Environmental heterogeneity and its influence on fern diversity: A case study in the low-altitude mountain forest in central Taiwan

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As ferns are highly sensitive to environmental fluctuations, they are often regarded as effective ecological indicators. This study investigates the influence of environmental variation on understory fern communities within a one-hectare permanent plot in a low-altitude mountainous forest in central Taiwan. A total of 51 fern species (including Lycophytes), belonging to 20 families and 30 genera, were recorded. Among these, 43 were terrestrial and eight epiphytic species; however, only terrestrial species were analyzed due to limited representation of epiphytes. Multiple regression analyses identified four to eight key environmental variables influencing fern richness, abundance, and composition, with topographic factors—particularly stream distance—being most frequently selected. Two-way indicator species analysis (TWINSPAN) categorized the ferns into four distinct groups, while Canonical Correspondence Analysis (CCA) revealed that elevation and stream distance significantly explained compositional variation among these groups. This study underscores the role of topographic and soil-related heterogeneity in structuring fern communities and highlights potential indicator species for future ecological monitoring in subtropical forest ecosystems. Biological sciences/Ecology Earth and environmental sciences/Ecology fern community topography soil properties biotic factors indicator species Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Environmental gradients exert strong influences on the diversity and spatial distribution of plant communities. At regional scales, climate variables such as temperature and precipitation are dominant drivers 1 – 3 . In contrast, at local scales, fine-scale topography, soil characteristics, and biological interactions play significant roles 4 – 9 . Among biotic factors, canopy structure and density are widely recognized for their influence on understory plant communities 10 , 11 . Ferns, the second largest group of vascular plants, are a dominant component of understory vegetation in tropical and subtropical forests 3 , 12 and are particularly sensitive to environmental heterogeneity. Topographic variables—such as elevation, slope, aspect, and stream proximity—shape microhabitats by altering light, temperature, and moisture regimes 13 , 14 . Even minor elevation changes at a local scale can distinguish ridges from valleys, influencing species assemblages 15 , 16 . For ferns, local topographical variation is known to affect both fern diversity 10 and abundance 17 . Stream proximity, in particular, is a strong predictor of fern assemblages 18 . Soil characteristics are also closely tied to plant distribution. Soil moisture (or humidity) are critical for the growth and development of ferns 5 , 19 . Variables such as nutrient content (e.g., N, P, K, Ca, Mg), pH, and organic matter significantly influence fern performance 5 , 18 , 20 . The carbon-to-nitrogen (C/N) ratio, in particular, serves as a proxy for soil fertility and has been linked to fern richness in several tropical studies 21 , 22 . Understory ferns depend on canopy-mediated light availability for growth and reproduction 23 , 24 . Canopy openness not only alters photosynthetically active radiation but also modulates temperature and humidity in the understory 25 . In Southeast Asia and Taiwan, canopy openness has been shown to correlate with fern richness and cover 10 , 26 . Furthermore, ferns interact with other plant groups. Dense fern layers can suppress tree seedling recruitment 27 , 28 , whereas diversity in co-occurring understory taxa can enhance fern richness 29 , 30 . These biotic interactions may result in mutual inhibition or facilitation depending on local environmental conditions. Given their sensitivity to microhabitat variation, ferns serve as ecological indicators of habitat condition 31 – 33 . However, in Taiwan, few studies have explicitly examined the micro-scale environmental determinants of fern community structure in natural low-altitude forests. This study investigates the relationship between environmental heterogeneity and fern diversity within a one-hectare plot embedded in a broader 25-hectare permanent plot in the Lienhuachih region, central Taiwan. We address the following questions: (1) Which environmental factors most strongly influence fern richness, abundance, and composition? (2) How do ferns cluster into ecological groups based on these factors? (3) Which species may serve as potential indicators for ecological monitoring in heterogeneous subtropical forests? Materials and methods Study area The study site is located in the Lienhuachih Experimental Forest (23°55'N, 120°52'E), situated in a low-altitude mountainous area of central Taiwan (Fig. 1 ). A one-hectare permanent plot was established within a natural forest and represents the northwest section of a broader 25-hectare forest dynamics plot initiated in 2007. The plot encompasses both mid-slope and riparian habitats. Based on earlier tree surveys (DBH ≥ 1 cm), two forest types were identified: one dominated by Diospyros morrisiana and Cryptocarya chinensis , and the other by Machilus japonica var. kusanoi and Helicia formosana 16 . The region experiences a mean annual temperature of 21.2°C and receives approximately 2,178 mm of precipitation annually, with rainfall concentrated from March to September and a dry season from October to November 26 . Sampling Design Vegetation data were collected using 10 m × 10 m subplots, within which all ferns, herbs, vines, and tree saplings were recorded. Fern abundance was assessed through counts and percent cover. Epiphytic ferns and vines were measured by the vertical projection of their canopy cover. Tree data (DBH ≥ 1 cm) were also recorded. Ferns were categorized as either terrestrial or epiphytic, with the former defined as growing on soil or rocks and the latter as occurring on tree trunks. Taxonomy follows Volume 6 of the Flora of Taiwan 34 and the classification by Kuo et al. 35 . Surveys were conducted from July 13 to 15, 2023. Environmental variables Topographic variables included elevation, plan curvature, slope, aspect, topographic wetness index (TWI), and distance to stream. Soil variables 36 included pH, carbon-to-nitrogen ratio (C/N), nitrogen, phosphorus, potassium, calcium, magnesium, manganese, zinc, iron, and copper. Soil data were collected at a 20 m × 20 m resolution, with values assigned to the nearest 10 m × 10 m subplot. Soil moisture was measured at 5 cm depth using a RiXEN M-700S meter between February 26 and March 3, 2024, averaged from three diagonal points per subplot. Canopy openness was measured from March 15 to 22, 2024, using spherical crown densiometers at 1.3 m height at the center of each 10 m × 10 m subplot. Statistical analysis The importance value (IV) for each fern species was calculated as the sum of its relative density and relative cover. Twenty-two environmental variables—spanning topography, soil properties, and biotic factors (canopy openness, tree density, sapling IV, and herb/vine IV)—were included in the analyses (Supplementary Table S1 ). Dependent variables were fern richness (species count), abundance (IV), and community composition (first two DCA axes). Forward stepwise multiple regression was used for model selection. Significant predictors (p 5 were excluded iteratively. Poisson regression was used for richness; linear regression for abundance and composition. Community classification was performed using TWINSPAN 37 , and indicator species were identified using IndVal 38 , 39 (Supplementary Note). Detrended correspondence analysis (DCA) 40 was used to ordinate species and plots. Canonical correspondence analysis (CCA) 41 related species distributions to environmental gradients. All analyses were performed in R v4.3.1. Results A total of 51 fern species representing 20 families and 30 genera were recorded within the one-hectare plot. Of these, 43 species were terrestrial and eight were epiphytic. Diplazium dilatatum was the most abundant species, with 1,011 individuals observed in 98 subplots, followed by Pleocnemia winitii with 567 individuals in 90 subplots. These two species accounted for 55.8% of the total abundance of terrestrial ferns (Table 1). In contrast, ten terrestrial species were found in only one subplot (Supplementary Table S2), representing 23.3% of the total terrestrial fern richness. In addition to ferns, 80 herb and vine species and 76 seedling species were recorded, bringing the total understory species count to 207. Due to limited abundance and patchy distribution, epiphytic ferns were excluded from further analyses but are documented in Supplementary Table S2. Among the environmental variables, elevation showed the highest number of significant correlations with soil properties (11), followed by slope (nine) and stream distance (seven) (Supplementary Table S3). Regression models (Table 2) revealed that fern richness was significantly influenced by stream distance (negatively) and sapling abundance (positively), among six selected variables. Fern abundance was most strongly associated with herb and vine cover. For fern composition, DCA1 was associated with stream distance, C/N ratio, manganese, and herb and vine cover—with the last two being significant. DCA2 included eight variables, among which elevation, curvature, slope, and TWI were significant. TWINSPAN classified the fern community into four groups (Fig. 2a): Diplazium donianum group (DIPLDO, n = 52), Dip. donianum var. aphanoneuron group (DIPLAP, n = 21), Blechnopsis orientalis group (BLECOR, n = 8), and Angiopteris lygodiifolia group (ANGILY, n = 19). Mean fern richness was lowest in DIPLDO (4.2 ± 1.9) and highest in ANGILY (6.4 ± 2.5) (Fig. 3). Indicator species analysis (Table 3) identified Diplazium donianum as the sole indicator for DIPLDO. DIPLAP was characterized by Diplazium donianum var. aphanoneuron and Pteris dimorpha var. dimorpha . BLECOR included Blechnopsis orientalis and Sphaerostephanos taiwanensis , while ANGILY was represented by Angiopteris lygodiifolia , Hymenasplenium excisum , and Hy. apogamum . The cumulative explained variance of the first three CCA axes was 9.7%, 16.5%, and 21.2%, respectively. In the biplot (Fig. 2b), DIPLDO and DIPLAP were mostly located at higher elevations, greater distances from streams, and gentler slopes (Fig. 4). BLECOR occupied low-lying areas closer to streams with higher C/N ratios (Fig. 4). ANGILY subplots were predominantly situated in riparian zones characterized by steep slopes (Fig. 4) and high humidity. The species ordination (Fig. 2c) showed dominant ferns ( Diplazium dilatatum and Pleocnemia winitii ) near the plot center, while indicator species aligned with the environmental characteristics of their respective TWINSPAN groups. For example, DIPLDO’s Diplazium donianum was located in the topographic and edaphic space indicative of drier, upland sites. ANGILY species clustered in moist, shaded streamside locations. Dicranopteris linearis was positively associated with canopy openness, suggesting a preference for higher light conditions compared to most other ferns. Discussion This study demonstrates that environmental heterogeneity strongly influences fern community composition, richness, and abundance in a subtropical low-altitude forest. The multivariate analyses confirm that topography—particularly elevation and stream distance—is the most influential driver of fern distribution. Soil characteristics, especially the carbon-to-nitrogen (C/N) ratio, also play an important role but are closely intertwined with topographic gradients. Biological factors, such as canopy openness and the abundance of coexisting plant groups (herbs, vines, saplings), exert additional influence, highlighting the multidimensional nature of environmental filtering in understory fern communities. Topographical effects Topography has long been recognized as a key determinant of forest vegetation patterns 8 , 42 , 43 . In this study, elevation and stream distance emerged as primary predictors of fern richness and composition, despite the modest elevation range (~ 59 m) within the plot. These gradients reflect moisture availability: higher elevation ridges with well-drained soils tend to be drier, while lower streamside zones retain more moisture. The strong correlation between elevation and stream distance (r = 0.40, p < 0.001) reinforces this interpretation. Our findings align with previous studies 5 , 10 , 18 in montane forests where even fine-scale topographic variation influences fern diversity. Soil effects Soil properties such as nutrient concentrations and organic matter content often co-vary with topography due to erosion, leaching, and deposition 44 , 45 . In our plot, C/N ratio was significantly associated with fern composition, particularly along the first CCA axis. Stream-adjacent soils, rich in organic matter and nitrogen, had elevated carbon-to-nitrogen (C/N) ratios due to greater accumulation of organic matter than decomposition in moist areas. Although fern richness was not directly correlated with C/N, its indirect effects via topographic mediation were evident. Calcium and manganese were also included in regression models, though their contributions were comparatively modest. Water availability, inferred through topographic wetness index (TWI), slope, and stream distance, likely exerts a dominant control on fern distributions. While soil moisture measurements did not emerge as significant predictors in the models, the strong influence of hydrologically relevant topographic variables suggests their overriding importance in determining local fern composition. Biotic influences Light availability is a well-documented driver of fern performance, affecting morphology, abundance, and richness 10 , 24 . Although canopy openness was not retained in final regression models, its significant correlation with tree density (r = − 0.22, p < 0.05) implies indirect effects. Denser tree canopies may reduce understory light, thus constraining fern growth. Interestingly, this study found positive associations between fern richness and both sapling and herb/vine cover, contrary to previous findings that emphasized competitive suppression 28 , 46 . This suggests potential facilitative interactions under specific microclimatic conditions, such as shaded and moist environments common in riparian zones. Tuomisto et al. similarly reported that fern and Melastomataceae diversity co-occurred with tree richness in fertile tropical soils 29 . Fern vegetation and habitat differentiation TWINSPAN and CCA revealed clear compositional differentiation among four fern groups, corresponding to distinct habitat types. DIPLDO and DIPLAP groups occupied ridge and upper slope habitats characterized by higher elevation and drier conditions. In contrast, BLECOR and ANGILY groups were associated with lower elevations, stream proximity, steeper slopes, and higher humidity. These habitat preferences support the role of environmental filtering in fern assembly and align with prior vegetation classifications within the same forest 16 . Ecological indicators Ferns are widely recognized as ecological indicators due to their sensitivity to environmental gradients 31 , 33 . This study identified several species with high indicator value scores. Diplazium donianum , its variety aphanoneuron , Pteris dimorpha var. dimorpha were associated with upland forest interiors, while Blechnopsis orientalis and Sphaerostephanos taiwanensis marked stream-adjacent open habitats. Angiopteris lygodiifolia and Hymenasplenium spp. were characteristic of moist, closed-canopy riparian zones. Conversely, widespread dominants like Diplazium dilatatum and Pleocnemia winitii lacked strong habitat specificity and are less suited as indicators. These findings underscore the utility of indicator species for long-term monitoring of microhabitat change. Conclusion This study highlights the significant role of environmental heterogeneity in shaping fern diversity and community composition in a low-altitude subtropical forest. Among the examined factors, topographic variables—particularly elevation and stream distance—exerted the strongest influence on fern richness, abundance, and species assemblage. Soil properties, especially the carbon-to-nitrogen (C/N) ratio, further mediated these relationships and reflected microhabitat variation. Although canopy openness was not directly retained in final models, its association with tree density and indirect effects on fern communities remain ecologically relevant. The classification of ferns into four ecological groups based on environmental gradients demonstrates the structuring effect of habitat differentiation. Species such as Diplazium donianum , Pteris dimorpha var. dimorpha, Blechnopsis orientalis , Sphaerostephanos taiwanensis, Angiopteris lygodiifolia , and Hymenasplenium spp. were identified as reliable ecological indicators, each associated with distinct environmental niches. These indicator species have narrow ecological tolerances and thus serve as effective tools for assessing forest microhabitats and monitoring environmental changes over time. Given the modest spatial scale of this study, future research should expand to larger plots and different forest types to evaluate the consistency and applicability of these findings across broader ecological gradients. Long-term monitoring incorporating both abiotic and biotic variables will be essential for understanding how fern communities respond to environmental change and for informing conservation strategies in subtropical forest ecosystems. Declarations Data availability The datasets utilized and/or analyzed during the current study are available from the first author upon reasonable request. Acknowledgements We thank the students of the Department of Forestry at National Chung Hsing University for their assistance in the wild investigation. Additional Information Author Contributions Statement Conception or design of the work: Pei-Hsuan Lee, Hsy-Yu Tzeng Data collection: Pei-Hsuan Lee, Li-Wan Chang, Jian-Hong Yang Data analysis and interpretation: Pei-Hsuan Lee Drafting the article: Pei-Hsuan Lee Critical revision of the article: Wen-Liang Chiou, Yao-Moan Huang, Hsy-Yu Tzeng, Yen-Hsueh Tseng All authors reviewed the manuscript. Competing Financial Interests statement The authors declare no competing financial interests. Supplementary Information Below is the link to the electronic supplementary material. Supplementary Material References Antonelli, A. et al. Geological and climatic influences on mountain biodiversity. Nat. Geosci. 11 , 718–725 (2018). Lin, H. Y. et al. Climate-based approach for modeling the distribution of montane forest vegetation in Taiwan. Appl. Veg. Sci. 23 , 239–253 (2020). Suissa, J. S., Sundue, M. A. & Testo, W. L. Mountains, climate and niche heterogeneity explain global patterns of fern diversity. J. Biogeogr. 48 , 1296–1308 (2021). Richard, M., Bernhardt, T. & Bell, G. Environmental heterogeneity and the spatial structure of fern species diversity in one hectare of old-growth forest. Ecography 23 , 231–245 (2000). Karst, J., Gilbert, B. & Lechowicz, M. J. Fern community assembly: The roles of chance and the environment at local and intermediate scales. Ecology 86 , 2473–2486 (2005). Bohlman, A. S. et al. Importance of soils, topography and geographic distance in structuring central Amazonian tree communities. J. Veg. Sci. 19 , 863–874 (2008). Da Silva, K. E. et al. Tree species community spatial structure in a terra firme Amazon forest, Brazil. Bosque (Valdivia) . 35 , 347–355 (2014). Zhou, T. et al. Biodiversity of Jinggangshan Mountain: The importance of topography and geographical location in supporting higher biodiversity. PLoS ONE 10 , (2015). Zuleta, D. et al. Importance of topography for tree species habitat distributions in a terra firme forest in the Colombian Amazon. Plant. Soil. 450 , 133–149 (2020). Jones, M. M., Cicuzza, D., Straaten, O., Veldkamp, E. & Kessler, M. Determinants of fern and angiosperm herb community structure in lower montane rainforest in Indonesia. J. Veg. Sci. 25 , 1216–1224 (2014). Mendes, C. N., Diniz, E. S., Terra, M. C. N. S., Jeannot, K. K. & Fontes, M. A. L. Light conditions imposed by canopy: Allometric strategies of an understorey palm (Geonoma schottianamart) in Atlantic forest. J. Trop. Sci. 31 , 332–342 (2019). Weigand, A. et al. Global fern and lycophyte richness explained: How regional and local factors shape plot richness. J. Biogeogr. 47 , 59–71 (2020). Chao, K. J., Chao, W. C., Chen, K. M. & Hsieh, C. F. Vegetation dynamics of a lowland rainforest at the northern border of the Paleotropics at Nanjenshan, southern Taiwan. Taiwan. J. Sci. 25 , 29–40 (2010). Moeslund, J. E., Arge, L., Bøcher, P. K., Dalgaard, T. & Svenning, J. C. Topography as a driver of local terrestrial vascular plant diversity patterns. Nord J. Bot 31 , (2013). Homeier, J., Breckle, S. W., Günter, S., Rollenbeck, R. T. & Leuschner, C. Tree diversity, forest structure and productivity along altitudinal and topographical gradients in a species-rich Ecuadorian montane rain forest. Biotropica 42 , 140–148 (2010). Chang, L. W. et al. Changes of plant communities classification and species composition along the micro-topography at the Lienhuachih forest dynamics plot in the central Taiwan. Taiwania 57 , 359–371 (2012). Cicuzza, D. & Mammides, C. Soil, topography and forest Structure shape the abundance, richness and composition of fern species in the fragmented tropical landscape of Xishuangbanna, Yunnan, China. Forests 13, (2022). Bonari, G. et al. Fine-scale fern ecological responses inform on riparian forest habitat conservation status. Biodivers. Conserv. 31 , 2141–2161 (2022). Poulsen, A. D., Tuomisto, H. & Balslev, H. Edaphic and floristic variation within a 1-ha plot of lowland Amazonian rain forest. Biotropica 38 , 468–478 (2006). Viana, J. L., Turner, B. L. & Dalling, J. W. Compositional variation in understorey fern and palm communities along a soil fertility and rainfall gradient in a lower montane tropical forest. J. Veg. Sci. 32 , 12947. https://doi.org/10.1111/jvs.12947 (2021). Lwanga, J. S., Balmford, A. & Badaza, R. Assessing fern diversity: Relative species richness and its environmental correlates in Uganda. Biodivers. Conserv. 7 , 1387–1398 (1998). Zuquim, G. et al. Predicting environmental gradients with fern species composition in Brazilian Amazonia. J. Veg. Sci. 25 , 1195–1207 (2014). Messier, C., Parent, S. & Bergeron, Y. Effects of overstory and understory vegetation on the understory light environment in mixed boreal forests. J. Veg. Sci. 9 , 511–520 (1998). Hill, J. D. & Silander, J. A. Distribution and dynamics of two ferns: Dennstaedtia punctilobula (Dennstaedtiaceae) and Thelypteris noveboracensis (Thelypteridaceae) in a Northeast mixed hardwoods–hemlock forest. Am. J. Bot. 88 , 894–902 (2001). Angelini, A., Corona, P., Chianucci, F. & Portoghesi, L. Structural attributes of stand overstory and light under the canopy. Ann. Silvic Res. 39 , 23–31. https://doi.org/10.12899/ASR-993 (2015). Lee, P. H., Huang, Y. M., Chiou, W. L., Tseng, Y. H. & Tzeng, H. Y. The correlation between fern diversity and environmental factors-case study in a Chinese Fir Plantation in Lienhuachih, central Taiwan. Taiwan. J. Sci. 39 , 271–289 (2024). George, L. O. & Bazzaz, F. A. The fern understory as an ecological filter: Growth and survival of canopy-tree seedlings. Ecology 80 , 846–856 (1999). Royo, A. A. & Carson, W. P. On the formation of dense understory layers in forests worldwide: Consequences and implications for forest dynamics, biodiversity, and succession. Can. J. Res. 36 , 1345–1362. https://doi.org/10.1139/X06-025 (2006). Tuomisto, H. et al. Distribution and diversity of pteridophytes and melastomataceae along edaphic gradients in Yasuní National Park, Ecuadorian Amazonia. Biotropica 34 , 516–533 (2002). Chang, L. W., Huang, J. L., Luo, S. F. & Lee, P. H. Understory plant composition and its relations with environmental factors of the Lienhuachih forest dynamics plot at a subtropical evergreen broadleaf forest in central Taiwan. Taiwan. J. Sci. 30 , 245–257 (2015). Ferrer-Castán, D. & Vetaas, O. R. Pteridophyte richness, climate and topography in the Iberian Peninsula: Comparing spatial and nonspatial models of richness patterns. Glob Ecol. Biogeogr. 14 , 155–165 (2005). Da Silva, V. L. & Schmitt, J. L. The effects of fragmentation on Araucaria forest: Analysis of the fern and lycophyte communities at sites subject to different edge conditions. Acta Bot. Brasilica . 29 , 223–230 (2015). Da Silva, V. L., Mehltreter, K. & Schmitt, J. L. Ferns as potential ecological indicators of edge effects in two types of Mexican forests. Ecol. Indic. 93 , 669–676 (2018). Boufford, D. E. et al. A Checklist of the Vascular Plants of Taiwan. in Flora of Taiwan, 2nd edition, Vol. 6 (ed. Editorial Committee of the Flora of Taiwan, S. E.) 15–139 (2003). Kuo, L. Y. et al. Updating taiwanese pteridophyte checklist: A new phylogenetic classification. Taiwania 64 , 367–395 (2019). Chang, L. W., Zelený, D., Li, C. F., Chiu, S. T. & Hsieh, C. F. Better environmental data may reverse conclusions about niche- and dispersal-based processes in community assembly. Ecology 94 , 2145–2151 (2013). Hill, M. TWINSPAN—A fortran program for arranging multivariate data in an ordered two-way table by classification of the individuals and attributes. in Ecology and Systematics (ed University, C.) (1979). Ithaca, N. Y.) (Cornell University. Section of Ecology and Systematics. De Cáceres, M. & Legendre, P. Associations between species and groups of sites: Indices and statistical inference. Ecology 90 , 3566–3574 (2009). De Cáceres, M., Legendre, P., Wiser, S. K. & Brotons, L. Using species combinations in indicator value analyses. Methods Ecol. Evol. 3 , 973–982 (2012). Hill, M. O. & Gauch, H. G. Detrended correspondence analysis: An improved ordination technique. Vegetatio 42 , 47–58 (1980). Ter Braak, C. J. F. Canonical correspondence analysis: A new eigenvector technique for multivariate direct gradient analysis. Ecology 67 , 1167–1179 (1986). Itoh, A. et al. Importance of topography and soil texture in the spatial distribution of two sympatric dipterocarp trees in a Bornean rainforest. Ecol. Res. 18 , 307–320 (2003). Jucker, T. et al. Topography shapes the structure, composition and function of tropical forest landscapes. Ecol. Lett. 21 , 989–1000 (2018). Wilcke, W. et al. Soil properties and tree growth along an altitudinal transect in Ecuadorian tropical montane forest. J. Plant. Nutr. Soil. Sci. 171 , 220–230 (2008). Chang, L. W. et al. Lienhuachih Subtropical Evergreen Broadleaf Forest Dynamics Plot Tree Species Characteristics and Distribution Patterns (Taiwan Forestry Research Institute, 2012). Liang, M. et al. Research progress on the ecology of dense fern understory. J. Trop. Subtrop Bot. 30 , 219–300 (2022). Tables Table 1. The number of subplot, relative individuals, and relative coverage for terrestrial species of fern in the one-hectare plot of the low-altitude natural forest of central Taiwan. The species doesn’t include the occurrence of 1 and 2 subplots. Scientific Name Abbreviation Subplot Relative individuals Relative coverage Alsophila podophylla Hook. ALSOPO 3 0.17 0.97 Angiopteris lygodiifolia Rosenst. ANGILY 21 1.50 2.73 Arachniodes amabilis (Blume) Tindale var. fimbriata K.Iwats ARACAM 3 0.21 0.43 Arachniodes pseudoaristata (Tagawa) Ohwi ARACPS 18 1.81 0.43 Blechnopsis orientalis (L.) C.Presl BLECOR 9 1.01 4.18 Christella parasitica (L.) H.Lév. ex Y.H.Chang CHRIPA 7 0.28 0.17 Cibotium barometz (L.) J.Sm. CIBOBA 34 3.48 10.71 Dicranopteris linearis (Burm.f.) Underw. DICRLI 4 0.42 0.07 Diplazium dilatatum Blume DIPLDI 98 35.21 37.25 Diplazium donianum (Mett.) Tardieu var. aphanoneuron (Ohwi) Tagawa DIPLAP 21 6.48 0.85 Diplazium donianum (Mett.) Tardieu var. donianum DIPLDO 33 10.76 1.81 Dryopteris polita Rosenst. DRYOPO 3 0.14 0.02 Hymenasplenium apogamum (N.Murak. & Hatan.) Nakaike HYMEAP 9 1.78 0.71 Hymenasplenium cheilosorum (Kunze ex Mett.) Tagawa HYMECH 7 0.87 0.29 Hymenasplenium excisum (C.Presl) S.Linds. HYMEEX 12 2.02 0.33 Leptochilus hemionitideus (C.Presl) Noot. LEPTHE 5 0.77 0.14 Lygodium japonicum (Thunb.) Sw. LYGOJA 4 0.31 0.71 Microlepia hookeriana (Wall. ex Hook.) C.Presl MICRHO 4 0.28 0.03 Microlepia marginata (Panzer) C.Chr. MICRMA 8 0.38 0.08 Microlepia obtusiloba Hayata MICROB 13 1.18 0.90 Microlepia speluncae (L.) T.Moore MICRSP 3 0.10 0.24 Pleocnemia winitii Holttum PLEOWI 90 19.75 16.70 Pteris arisanensis Tagawa PTERAR 10 0.45 1.45 Pteris dimorpha Copel. PTERDI 18 1.78 0.10 Pteris grevilleana Wall. ex J. Agardh PTERGR 4 0.35 0.01 Selaginella doederleinii Hieron. SELADO 5 0.42 0.57 Sphaerostephanos taiwanensis (C.Chr.) Holttum ex C.M.Kuo SPHATA 6 1.78 7.69 Tectaria simonsii (Baker) Ching TECTSI 26 2.58 0.93 Table 2. Environmental factor models in a one-hectare natural forest plot in Lienhuachih used Poisson regression for fern richness and linear regression for fern abundance and composition (two DCA axes). Model fit was assessed using the Akaike Information Criterion (AIC), where smaller values indicate a better fit. “VIF” indicates the Variance Inflation Factor test. *: p < 0.05; **: p < 0.01; ***: p < 0.001. Variables Estimate Standard Error VIF Fern richness [AIC: 421.16] Elevation -0.0010 0.0041 1.80 Curvature 0.0068 0.0144 2.07 TWI 0.1374 0.0927 2.37 Stream distance -0.0106 * 0.0053 1.75 Ca -0.0030 0.0043 1.61 Sapling 0.0039 * 0.0019 1.08 Fern abundance [AIC: 402.7] Elevation -0.0104 0.0136 1.33 Stream distance -0.0045 0.0202 1.90 C/N 0.3507 0.2620 1.49 Tree’s density 0.0094 0.0184 1.50 Herb & vine 1.0151 *** 0.1365 1.37 Sapling -0.0081 0.0092 1.33 DCA1 [AIC: 153.55] Stream distance 0.0038 0.0052 1.48 C/N 0.3024 *** 0.0759 1.48 Mn -0.0073 * 0.0034 1.01 Herb & vine 0.0963 ** 0.0362 1.14 DCA2 [AIC: 123.01] Elevation -0.0164 *** 0.0044 2.38 Curvature 0.0478 ** 0.0170 3.17 Slope 0.0229 * 0.0092 2.30 TWI 0.3635 ** 0.1136 3.68 Stream distance -0.0016 0.0068 3.60 C/N 0.1350 0.0708 1.81 Ca -0.0030 0.0042 1.74 Tree’s density -0.0066 0.0047 1.63 Table 3. Indicator value analysis (IndVal) results in the 1ha plot of Lienhuachih, the low-altitude natural forest of central Taiwan. Detail in the Supplementary. Species A B sqrtIV p Group of DIPLDO Diplazium donianum var. donianum 0.974 0.571 0.645 0.005 Group of DIPLAP Diplazium donianum var. aphanoneuron 0.728 0.571 0.645 0.005 Pteris dimorpha var. dimorpha 0.727 0.429 0.558 0.005 Group of BLECOR Blechnopsis orientalis 0.833 1 0.913 0.005 Sphaerostephanos taiwanensis 1.000 0.75 0.866 0.005 Group of ANGILY Angiopteris lygodiifolia 0.736 0.789 0.762 0.005 Hymenasplenium apogamum 0.929 0.316 0.542 0.005 Hymenasplenium excisum 1.000 0.632 0.795 0.005 Additional Declarations No competing interests reported. Supplementary Files SupplementaryMaterialchiouLee1.docx Cite Share Download PDF Status: Published Journal Publication published 23 Dec, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 28 Jul, 2025 Reviews received at journal 16 Jul, 2025 Reviewers agreed at journal 24 Jun, 2025 Reviews received at journal 19 Jun, 2025 Reviewers agreed at journal 09 Jun, 2025 Reviewers invited by journal 08 Jun, 2025 Editor assigned by journal 08 Jun, 2025 Editor invited by journal 06 Jun, 2025 Submission checks completed at journal 06 Jun, 2025 First submitted to journal 28 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6772342","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":468379324,"identity":"0c8477b7-47de-40e1-8b73-d7a837c69891","order_by":0,"name":"Pei Hsuan Lee","email":"","orcid":"","institution":"National Chung Hsing University","correspondingAuthor":false,"prefix":"","firstName":"Pei","middleName":"Hsuan","lastName":"Lee","suffix":""},{"id":468379325,"identity":"caba324d-4bd0-4679-b613-7c9155eaf1b7","order_by":1,"name":"Yao Moan Huang","email":"","orcid":"","institution":"Taiwan Forestry Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Yao","middleName":"Moan","lastName":"Huang","suffix":""},{"id":468379327,"identity":"20939bfe-6074-41e0-bf1d-78560d1785f3","order_by":2,"name":"Li Wan Chang","email":"","orcid":"","institution":"Taiwan Forestry Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"Wan","lastName":"Chang","suffix":""},{"id":468379329,"identity":"af3b3fc6-a83c-48c1-9404-e1cb1e95a094","order_by":3,"name":"Jian Hong Yang","email":"","orcid":"","institution":"Taiwan Forestry Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"Hong","lastName":"Yang","suffix":""},{"id":468379332,"identity":"d6a79bad-83d1-4de8-a69b-b754008b6487","order_by":4,"name":"Wen Liang Chiou","email":"","orcid":"","institution":"Taiwan Forestry Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Wen","middleName":"Liang","lastName":"Chiou","suffix":""},{"id":468379334,"identity":"7a61ad5f-daed-4048-938a-580de48803da","order_by":5,"name":"Yen Hsueh Tseng","email":"","orcid":"","institution":"Taiwan Forestry Research Institute","correspondingAuthor":false,"prefix":"","firstName":"Yen","middleName":"Hsueh","lastName":"Tseng","suffix":""},{"id":468379335,"identity":"1625caae-a052-4ac0-991f-7bda0f15fcff","order_by":6,"name":"Hsy Yu Tzeng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYPACG8YGGNMARPAQ0nCAIQ1TiwQBLYdJ0MIvffjg5w8152W3tx+/+LiA4Y68uUQC44O3bQx1Bgewa5HsS0uWOHDstvGcMznFxjMYnhnunJHAbDi3jUEClxaDMzxmDAfYbifOYMhJk+ZhOJxgcCOBTZoXqMUMhxb7M/zfGA78O5c4g/8NXAv7b3xaDHh42BgOth1InCGRfgxuCzM+LRJn2IwlzvYlG8+QeMNszGNw2HDDmYfNknPOSUjux6GFv4f54YeKb3ayM/jTHz7mqTgsb3A8+eCHN2U2/JIN2LUgAR4DaKSA4wh/TEIB+wNiVI2CUTAKRsEIBAAPC1pwcoGJ8QAAAABJRU5ErkJggg==","orcid":"","institution":"National Chung Hsing University","correspondingAuthor":true,"prefix":"","firstName":"Hsy","middleName":"Yu","lastName":"Tzeng","suffix":""}],"badges":[],"createdAt":"2025-05-29 03:38:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6772342/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6772342/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-025-28048-9","type":"published","date":"2025-12-23T15:57:33+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":84381002,"identity":"62a880da-3a83-44b7-a54e-64a6ddd38518","added_by":"auto","created_at":"2025-06-11 09:15:32","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":393809,"visible":true,"origin":"","legend":"\u003cp\u003eThe Taiwan map (left) and a topographic map (right) of the one-hectare natural forest plot in Lienhuachih within Houloun stream catchment, a mountainous region in central Taiwan.\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/840b2711fbad7e7ef5cbe63d.jpg"},{"id":84381907,"identity":"a4472709-6dc5-482e-b1b0-7d1c0db657dc","added_by":"auto","created_at":"2025-06-11 09:23:32","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":236294,"visible":true,"origin":"","legend":"\u003cp\u003eTWINSPAN and CCA from a one-hectare natural forest plot in the Lienhuachih area of central Taiwan. a) TWINSPAN identified four fern groups: DIPLDO (□), DIPLAP (△), BLECOR (○), and ANGILY (●). b) The figure of the first two axes from CCA; the words beside lines represent environmental and biological factors, and the direction indicates the trend in which the value increases. c) The same analysis as in b, with the letters representing the fern species (see Table 1).\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/e37b0232c040e2cf267d71bd.jpg"},{"id":84383154,"identity":"fd2d767c-4fab-4fec-be73-cc318c486e59","added_by":"auto","created_at":"2025-06-11 09:31:32","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":48812,"visible":true,"origin":"","legend":"\u003cp\u003eThe richness of fern vegetation within the one-hectare natural forest plot located in the Lienhuachih area of central Taiwan. Distinct letters denote statistically significant differences among various fern vegetation (p \u0026lt; 0.05). Fern vegetation: 1-DIPLDO, 2-DIPLAP, 3-BLECOR, 4-ANGILY.\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/7230376b2149b7d8df7aaad2.jpg"},{"id":84384151,"identity":"ee1a428b-6e17-410d-a891-84ab56cd8f9d","added_by":"auto","created_at":"2025-06-11 09:39:32","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":126599,"visible":true,"origin":"","legend":"\u003cp\u003eThe variations in elevation (a), stream distance (b), slope (c), and C/N (d) among different fern communities. Different letters denote statistically significant differences among the different fern vegetation (p \u0026lt; 0.05). Fern vegetation: 1- DIPLDO, 2- DIPLAP, 3- BLECOR, 4- ANGILY.\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/9b6464ac422ab6bdb245b09c.jpg"},{"id":99172276,"identity":"81420608-dcb5-4860-8b88-e6daeb292193","added_by":"auto","created_at":"2025-12-29 16:07:01","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1713654,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/94047a6e-0e6d-4ac0-b3e5-46a8957111c7.pdf"},{"id":84381001,"identity":"de0aa892-e2b6-4e72-b7dd-548fcd84d449","added_by":"auto","created_at":"2025-06-11 09:15:32","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":56414,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMaterialchiouLee1.docx","url":"https://assets-eu.researchsquare.com/files/rs-6772342/v1/b064614e77dbbd98e85287d7.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Environmental heterogeneity and its influence on fern diversity: A case study in the low-altitude mountain forest in central Taiwan","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEnvironmental gradients exert strong influences on the diversity and spatial distribution of plant communities. At regional scales, climate variables such as temperature and precipitation are dominant drivers\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. In contrast, at local scales, fine-scale topography, soil characteristics, and biological interactions play significant roles\u003csup\u003e\u003cspan additionalcitationids=\"CR5 CR6 CR7 CR8\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. Among biotic factors, canopy structure and density are widely recognized for their influence on understory plant communities\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Ferns, the second largest group of vascular plants, are a dominant component of understory vegetation in tropical and subtropical forests\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e,\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e and are particularly sensitive to environmental heterogeneity.\u003c/p\u003e \u003cp\u003eTopographic variables\u0026mdash;such as elevation, slope, aspect, and stream proximity\u0026mdash;shape microhabitats by altering light, temperature, and moisture regimes\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e,\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Even minor elevation changes at a local scale can distinguish ridges from valleys, influencing species assemblages\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. For ferns, local topographical variation is known to affect both fern diversity\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e and abundance\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Stream proximity, in particular, is a strong predictor of fern assemblages\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSoil characteristics are also closely tied to plant distribution. Soil moisture (or humidity) are critical for the growth and development of ferns \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Variables such as nutrient content (e.g., N, P, K, Ca, Mg), pH, and organic matter significantly influence fern performance \u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e,\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. The carbon-to-nitrogen (C/N) ratio, in particular, serves as a proxy for soil fertility and has been linked to fern richness in several tropical studies\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e,\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eUnderstory ferns depend on canopy-mediated light availability for growth and reproduction\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e,\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. Canopy openness not only alters photosynthetically active radiation but also modulates temperature and humidity in the understory\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. In Southeast Asia and Taiwan, canopy openness has been shown to correlate with fern richness and cover\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eFurthermore, ferns interact with other plant groups. Dense fern layers can suppress tree seedling recruitment\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e, whereas diversity in co-occurring understory taxa can enhance fern richness\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e,\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. These biotic interactions may result in mutual inhibition or facilitation depending on local environmental conditions.\u003c/p\u003e \u003cp\u003eGiven their sensitivity to microhabitat variation, ferns serve as ecological indicators of habitat condition\u003csup\u003e\u003cspan additionalcitationids=\"CR32\" citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. However, in Taiwan, few studies have explicitly examined the micro-scale environmental determinants of fern community structure in natural low-altitude forests.\u003c/p\u003e \u003cp\u003eThis study investigates the relationship between environmental heterogeneity and fern diversity within a one-hectare plot embedded in a broader 25-hectare permanent plot in the Lienhuachih region, central Taiwan. We address the following questions: (1) Which environmental factors most strongly influence fern richness, abundance, and composition? (2) How do ferns cluster into ecological groups based on these factors? (3) Which species may serve as potential indicators for ecological monitoring in heterogeneous subtropical forests?\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy area\u003c/h2\u003e \u003cp\u003eThe study site is located in the Lienhuachih Experimental Forest (23\u0026deg;55'N, 120\u0026deg;52'E), situated in a low-altitude mountainous area of central Taiwan (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). A one-hectare permanent plot was established within a natural forest and represents the northwest section of a broader 25-hectare forest dynamics plot initiated in 2007. The plot encompasses both mid-slope and riparian habitats. Based on earlier tree surveys (DBH\u0026thinsp;\u0026ge;\u0026thinsp;1 cm), two forest types were identified: one dominated by \u003cem\u003eDiospyros morrisiana\u003c/em\u003e and \u003cem\u003eCryptocarya chinensis\u003c/em\u003e, and the other by \u003cem\u003eMachilus japonica\u003c/em\u003e var. \u003cem\u003ekusanoi\u003c/em\u003e and \u003cem\u003eHelicia formosana\u003c/em\u003e\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. The region experiences a mean annual temperature of 21.2\u0026deg;C and receives approximately 2,178 mm of precipitation annually, with rainfall concentrated from March to September and a dry season from October to November\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSampling Design\u003c/h3\u003e\n\u003cp\u003eVegetation data were collected using 10 m \u0026times; 10 m subplots, within which all ferns, herbs, vines, and tree saplings were recorded. Fern abundance was assessed through counts and percent cover. Epiphytic ferns and vines were measured by the vertical projection of their canopy cover. Tree data (DBH\u0026thinsp;\u0026ge;\u0026thinsp;1 cm) were also recorded. Ferns were categorized as either terrestrial or epiphytic, with the former defined as growing on soil or rocks and the latter as occurring on tree trunks. Taxonomy follows Volume 6 of the Flora of Taiwan\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e and the classification by Kuo et al.\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. Surveys were conducted from July 13 to 15, 2023.\u003c/p\u003e\n\u003ch3\u003eEnvironmental variables\u003c/h3\u003e\n\u003cp\u003eTopographic variables included elevation, plan curvature, slope, aspect, topographic wetness index (TWI), and distance to stream. Soil variables\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e included pH, carbon-to-nitrogen ratio (C/N), nitrogen, phosphorus, potassium, calcium, magnesium, manganese, zinc, iron, and copper. Soil data were collected at a 20 m \u0026times; 20 m resolution, with values assigned to the nearest 10 m \u0026times; 10 m subplot. Soil moisture was measured at 5 cm depth using a RiXEN M-700S meter between February 26 and March 3, 2024, averaged from three diagonal points per subplot. Canopy openness was measured from March 15 to 22, 2024, using spherical crown densiometers at 1.3 m height at the center of each 10 m \u0026times; 10 m subplot.\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe importance value (IV) for each fern species was calculated as the sum of its relative density and relative cover. Twenty-two environmental variables\u0026mdash;spanning topography, soil properties, and biotic factors (canopy openness, tree density, sapling IV, and herb/vine IV)\u0026mdash;were included in the analyses (Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). Dependent variables were fern richness (species count), abundance (IV), and community composition (first two DCA axes). Forward stepwise multiple regression was used for model selection. Significant predictors (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05, Chi-squared test or F-test) were included, and collinearity was assessed using the Variance Inflation Factor (VIF). Variables with VIF\u0026thinsp;\u0026gt;\u0026thinsp;5 were excluded iteratively. Poisson regression was used for richness; linear regression for abundance and composition.\u003c/p\u003e \u003cp\u003eCommunity classification was performed using TWINSPAN\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e, and indicator species were identified using IndVal\u003csup\u003e\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e,\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e (Supplementary Note). Detrended correspondence analysis (DCA)\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e was used to ordinate species and plots. Canonical correspondence analysis (CCA)\u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e related species distributions to environmental gradients. All analyses were performed in R v4.3.1.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 51 fern species representing 20 families and 30 genera were recorded within the one-hectare plot. Of these, 43 species were terrestrial and eight were epiphytic. \u003cem\u003eDiplazium dilatatum\u003c/em\u003e was the most abundant species, with 1,011 individuals observed in 98 subplots, followed by \u003cem\u003ePleocnemia winitii\u003c/em\u003e with 567 individuals in 90 subplots. These two species accounted for 55.8% of the total abundance of terrestrial ferns (Table 1). In contrast, ten terrestrial species were found in only one subplot (Supplementary Table S2), representing 23.3% of the total terrestrial fern richness.\u003c/p\u003e\n\u003cp\u003eIn addition to ferns, 80 herb and vine species and 76 seedling species were recorded, bringing the total understory species count to 207. Due to limited abundance and patchy distribution, epiphytic ferns were excluded from further analyses but are documented in Supplementary Table S2. Among the environmental variables, elevation showed the highest number of significant correlations with soil properties (11), followed by slope (nine) and stream distance (seven) (Supplementary Table S3).\u003c/p\u003e\n\u003cp\u003eRegression models (Table 2) revealed that fern richness was significantly influenced by stream distance (negatively) and sapling abundance (positively), among six selected variables. Fern abundance was most strongly associated with herb and vine cover. For fern composition, DCA1 was associated with stream distance, C/N ratio, manganese, and herb and vine cover\u0026mdash;with the last two being significant. DCA2 included eight variables, among which elevation, curvature, slope, and TWI were significant.\u003c/p\u003e\n\u003cp\u003eTWINSPAN classified the fern community into four groups (Fig. 2a): \u003cem\u003eDiplazium donianum\u003c/em\u003e group (DIPLDO, n = 52),\u003cem\u003e\u0026nbsp;Dip. donianum\u0026nbsp;\u003c/em\u003evar.\u003cem\u003e\u0026nbsp;aphanoneuron\u003c/em\u003e group (DIPLAP, n = 21), \u003cem\u003eBlechnopsis orientalis\u003c/em\u003e group (BLECOR, n = 8), and \u003cem\u003eAngiopteris lygodiifolia\u003c/em\u003e group (ANGILY, n = 19). Mean fern richness was lowest in DIPLDO (4.2 \u0026plusmn; 1.9) and highest in ANGILY (6.4 \u0026plusmn; 2.5) (Fig. 3). Indicator species analysis (Table 3) identified \u003cem\u003eDiplazium donianum\u003c/em\u003e as the sole indicator for DIPLDO. DIPLAP was characterized by \u003cem\u003eDiplazium donianum\u0026nbsp;\u003c/em\u003evar.\u003cem\u003e\u0026nbsp;aphanoneuron\u0026nbsp;\u003c/em\u003eand\u003cem\u003e\u0026nbsp;Pteris dimorpha\u0026nbsp;\u003c/em\u003evar.\u003cem\u003e\u0026nbsp;dimorpha\u003c/em\u003e. BLECOR included \u003cem\u003eBlechnopsis orientalis\u003c/em\u003e and \u003cem\u003eSphaerostephanos taiwanensis\u003c/em\u003e, while ANGILY was represented by\u003cem\u003e\u0026nbsp;Angiopteris lygodiifolia\u003c/em\u003e, \u003cem\u003eHymenasplenium excisum\u003c/em\u003e, and\u003cem\u003e\u0026nbsp;Hy. apogamum\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003eThe cumulative explained variance of the first three CCA axes was 9.7%, 16.5%, and 21.2%, respectively. In the biplot (Fig. 2b), DIPLDO and DIPLAP were mostly located at higher elevations, greater distances from streams, and gentler slopes (Fig. 4). BLECOR occupied low-lying areas closer to streams with higher C/N ratios (Fig. 4). ANGILY subplots were predominantly situated in riparian zones characterized by steep slopes (Fig. 4) and high humidity.\u003c/p\u003e\n\u003cp\u003eThe species ordination (Fig. 2c) showed dominant ferns (\u003cem\u003eDiplazium dilatatum\u003c/em\u003e and \u003cem\u003ePleocnemia winitii\u003c/em\u003e) near the plot center, while indicator species aligned with the environmental characteristics of their respective TWINSPAN groups. For example, DIPLDO\u0026rsquo;s \u003cem\u003eDiplazium donianum\u003c/em\u003e was located in the topographic and edaphic space indicative of drier, upland sites. ANGILY species clustered in moist, shaded streamside locations. \u003cem\u003eDicranopteris linearis\u003c/em\u003e was positively associated with canopy openness, suggesting a preference for higher light conditions compared to most other ferns.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study demonstrates that environmental heterogeneity strongly influences fern community composition, richness, and abundance in a subtropical low-altitude forest. The multivariate analyses confirm that topography\u0026mdash;particularly elevation and stream distance\u0026mdash;is the most influential driver of fern distribution. Soil characteristics, especially the carbon-to-nitrogen (C/N) ratio, also play an important role but are closely intertwined with topographic gradients. Biological factors, such as canopy openness and the abundance of coexisting plant groups (herbs, vines, saplings), exert additional influence, highlighting the multidimensional nature of environmental filtering in understory fern communities.\u003c/p\u003e\n\u003ch3\u003eTopographical effects\u003c/h3\u003e\n\u003cp\u003eTopography has long been recognized as a key determinant of forest vegetation patterns\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e,\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. In this study, elevation and stream distance emerged as primary predictors of fern richness and composition, despite the modest elevation range (~\u0026thinsp;59 m) within the plot. These gradients reflect moisture availability: higher elevation ridges with well-drained soils tend to be drier, while lower streamside zones retain more moisture. The strong correlation between elevation and stream distance (r\u0026thinsp;=\u0026thinsp;0.40, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) reinforces this interpretation. Our findings align with previous studies\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e in montane forests where even fine-scale topographic variation influences fern diversity.\u003c/p\u003e\n\u003ch3\u003eSoil effects\u003c/h3\u003e\n\u003cp\u003eSoil properties such as nutrient concentrations and organic matter content often co-vary with topography due to erosion, leaching, and deposition\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e,\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e. In our plot, C/N ratio was significantly associated with fern composition, particularly along the first CCA axis. Stream-adjacent soils, rich in organic matter and nitrogen, had elevated carbon-to-nitrogen (C/N) ratios due to greater accumulation of organic matter than decomposition in moist areas. Although fern richness was not directly correlated with C/N, its indirect effects via topographic mediation were evident. Calcium and manganese were also included in regression models, though their contributions were comparatively modest.\u003c/p\u003e \u003cp\u003eWater availability, inferred through topographic wetness index (TWI), slope, and stream distance, likely exerts a dominant control on fern distributions. While soil moisture measurements did not emerge as significant predictors in the models, the strong influence of hydrologically relevant topographic variables suggests their overriding importance in determining local fern composition.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eBiotic influences\u003c/h2\u003e \u003cp\u003eLight availability is a well-documented driver of fern performance, affecting morphology, abundance, and richness\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. Although canopy openness was not retained in final regression models, its significant correlation with tree density (r = \u0026minus;\u0026thinsp;0.22, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05) implies indirect effects. Denser tree canopies may reduce understory light, thus constraining fern growth.\u003c/p\u003e \u003cp\u003eInterestingly, this study found positive associations between fern richness and both sapling and herb/vine cover, contrary to previous findings that emphasized competitive suppression\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e,\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. This suggests potential facilitative interactions under specific microclimatic conditions, such as shaded and moist environments common in riparian zones. Tuomisto et al. similarly reported that fern and Melastomataceae diversity co-occurred with tree richness in fertile tropical soils\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eFern vegetation and habitat differentiation\u003c/h2\u003e \u003cp\u003eTWINSPAN and CCA revealed clear compositional differentiation among four fern groups, corresponding to distinct habitat types. DIPLDO and DIPLAP groups occupied ridge and upper slope habitats characterized by higher elevation and drier conditions. In contrast, BLECOR and ANGILY groups were associated with lower elevations, stream proximity, steeper slopes, and higher humidity. These habitat preferences support the role of environmental filtering in fern assembly and align with prior vegetation classifications within the same forest\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eEcological indicators\u003c/h2\u003e \u003cp\u003eFerns are widely recognized as ecological indicators due to their sensitivity to environmental gradients\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e,\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. This study identified several species with high indicator value scores. \u003cem\u003eDiplazium donianum\u003c/em\u003e, its variety \u003cem\u003eaphanoneuron\u003c/em\u003e, \u003cem\u003ePteris dimorpha\u003c/em\u003e var. \u003cem\u003edimorpha\u003c/em\u003e were associated with upland forest interiors, while \u003cem\u003eBlechnopsis orientalis\u003c/em\u003e and \u003cem\u003eSphaerostephanos taiwanensis\u003c/em\u003e marked stream-adjacent open habitats. \u003cem\u003eAngiopteris lygodiifolia\u003c/em\u003e and \u003cem\u003eHymenasplenium\u003c/em\u003e spp. were characteristic of moist, closed-canopy riparian zones. Conversely, widespread dominants like \u003cem\u003eDiplazium dilatatum\u003c/em\u003e and \u003cem\u003ePleocnemia winitii\u003c/em\u003e lacked strong habitat specificity and are less suited as indicators. These findings underscore the utility of indicator species for long-term monitoring of microhabitat change.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis study highlights the significant role of environmental heterogeneity in shaping fern diversity and community composition in a low-altitude subtropical forest. Among the examined factors, topographic variables\u0026mdash;particularly elevation and stream distance\u0026mdash;exerted the strongest influence on fern richness, abundance, and species assemblage. Soil properties, especially the carbon-to-nitrogen (C/N) ratio, further mediated these relationships and reflected microhabitat variation. Although canopy openness was not directly retained in final models, its association with tree density and indirect effects on fern communities remain ecologically relevant.\u003c/p\u003e \u003cp\u003eThe classification of ferns into four ecological groups based on environmental gradients demonstrates the structuring effect of habitat differentiation. Species such as \u003cem\u003eDiplazium donianum\u003c/em\u003e, \u003cem\u003ePteris dimorpha\u003c/em\u003e var. \u003cem\u003edimorpha, Blechnopsis orientalis\u003c/em\u003e, \u003cem\u003eSphaerostephanos taiwanensis, Angiopteris lygodiifolia\u003c/em\u003e, and \u003cem\u003eHymenasplenium\u003c/em\u003e spp. were identified as reliable ecological indicators, each associated with distinct environmental niches. These indicator species have narrow ecological tolerances and thus serve as effective tools for assessing forest microhabitats and monitoring environmental changes over time.\u003c/p\u003e \u003cp\u003eGiven the modest spatial scale of this study, future research should expand to larger plots and different forest types to evaluate the consistency and applicability of these findings across broader ecological gradients. Long-term monitoring incorporating both abiotic and biotic variables will be essential for understanding how fern communities respond to environmental change and for informing conservation strategies in subtropical forest ecosystems.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets utilized and/or analyzed during the current study are available from the first author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the students of the Department of Forestry at National Chung Hsing University for their assistance in the wild investigation.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional Information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConception or design of the work: Pei-Hsuan Lee, Hsy-Yu Tzeng\u003c/p\u003e\n\u003cp\u003eData collection: Pei-Hsuan Lee, Li-Wan Chang, Jian-Hong Yang\u003c/p\u003e\n\u003cp\u003eData analysis and interpretation: Pei-Hsuan Lee\u003c/p\u003e\n\u003cp\u003eDrafting the article: Pei-Hsuan Lee\u003c/p\u003e\n\u003cp\u003eCritical revision of the article: Wen-Liang Chiou, Yao-Moan Huang, Hsy-Yu Tzeng, Yen-Hsueh Tseng\u003c/p\u003e\n\u003cp\u003eAll authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Financial Interests statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing financial interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplementary Information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBelow is the link to the electronic supplementary material.\u003c/p\u003e\n\u003cp\u003eSupplementary Material\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAntonelli, A. et al. Geological and climatic influences on mountain biodiversity. \u003cem\u003eNat. Geosci.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e, 718\u0026ndash;725 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLin, H. Y. et al. Climate-based approach for modeling the distribution of montane forest vegetation in Taiwan. \u003cem\u003eAppl. Veg. Sci.\u003c/em\u003e \u003cb\u003e23\u003c/b\u003e, 239\u0026ndash;253 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuissa, J. S., Sundue, M. A. \u0026amp; Testo, W. L. Mountains, climate and niche heterogeneity explain global patterns of fern diversity. \u003cem\u003eJ. Biogeogr.\u003c/em\u003e \u003cb\u003e48\u003c/b\u003e, 1296\u0026ndash;1308 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRichard, M., Bernhardt, T. \u0026amp; Bell, G. Environmental heterogeneity and the spatial structure of fern species diversity in one hectare of old-growth forest. \u003cem\u003eEcography\u003c/em\u003e \u003cb\u003e23\u003c/b\u003e, 231\u0026ndash;245 (2000).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKarst, J., Gilbert, B. \u0026amp; Lechowicz, M. J. Fern community assembly: The roles of chance and the environment at local and intermediate scales. \u003cem\u003eEcology\u003c/em\u003e \u003cb\u003e86\u003c/b\u003e, 2473\u0026ndash;2486 (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBohlman, A. S. et al. Importance of soils, topography and geographic distance in structuring central Amazonian tree communities. \u003cem\u003eJ. Veg. Sci.\u003c/em\u003e \u003cb\u003e19\u003c/b\u003e, 863\u0026ndash;874 (2008).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDa Silva, K. E. et al. Tree species community spatial structure in a terra firme Amazon forest, Brazil. \u003cem\u003eBosque (Valdivia)\u003c/em\u003e. \u003cb\u003e35\u003c/b\u003e, 347\u0026ndash;355 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhou, T. et al. Biodiversity of Jinggangshan Mountain: The importance of topography and geographical location in supporting higher biodiversity. \u003cem\u003ePLoS ONE\u003c/em\u003e \u003cb\u003e10\u003c/b\u003e, (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZuleta, D. et al. Importance of topography for tree species habitat distributions in a terra firme forest in the Colombian Amazon. \u003cem\u003ePlant. Soil.\u003c/em\u003e \u003cb\u003e450\u003c/b\u003e, 133\u0026ndash;149 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJones, M. M., Cicuzza, D., Straaten, O., Veldkamp, E. \u0026amp; Kessler, M. Determinants of fern and angiosperm herb community structure in lower montane rainforest in Indonesia. \u003cem\u003eJ. Veg. Sci.\u003c/em\u003e \u003cb\u003e25\u003c/b\u003e, 1216\u0026ndash;1224 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMendes, C. N., Diniz, E. S., Terra, M. C. N. S., Jeannot, K. K. \u0026amp; Fontes, M. A. L. Light conditions imposed by canopy: Allometric strategies of an understorey palm (Geonoma schottianamart) in Atlantic forest. \u003cem\u003eJ. Trop. Sci.\u003c/em\u003e \u003cb\u003e31\u003c/b\u003e, 332\u0026ndash;342 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWeigand, A. et al. Global fern and lycophyte richness explained: How regional and local factors shape plot richness. \u003cem\u003eJ. Biogeogr.\u003c/em\u003e \u003cb\u003e47\u003c/b\u003e, 59\u0026ndash;71 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChao, K. J., Chao, W. C., Chen, K. M. \u0026amp; Hsieh, C. F. Vegetation dynamics of a lowland rainforest at the northern border of the Paleotropics at Nanjenshan, southern Taiwan. \u003cem\u003eTaiwan. J. Sci.\u003c/em\u003e \u003cb\u003e25\u003c/b\u003e, 29\u0026ndash;40 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoeslund, J. E., Arge, L., B\u0026oslash;cher, P. K., Dalgaard, T. \u0026amp; Svenning, J. C. Topography as a driver of local terrestrial vascular plant diversity patterns. \u003cem\u003eNord J. Bot\u003c/em\u003e \u003cb\u003e31\u003c/b\u003e, (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHomeier, J., Breckle, S. W., G\u0026uuml;nter, S., Rollenbeck, R. T. \u0026amp; Leuschner, C. Tree diversity, forest structure and productivity along altitudinal and topographical gradients in a species-rich Ecuadorian montane rain forest. \u003cem\u003eBiotropica\u003c/em\u003e \u003cb\u003e42\u003c/b\u003e, 140\u0026ndash;148 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang, L. W. et al. Changes of plant communities classification and species composition along the micro-topography at the Lienhuachih forest dynamics plot in the central Taiwan. \u003cem\u003eTaiwania\u003c/em\u003e \u003cb\u003e57\u003c/b\u003e, 359\u0026ndash;371 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCicuzza, D. \u0026amp; Mammides, C. Soil, topography and forest Structure shape the abundance, richness and composition of fern species in the fragmented tropical landscape of Xishuangbanna, Yunnan, China. \u003cem\u003eForests\u003c/em\u003e 13, (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBonari, G. et al. Fine-scale fern ecological responses inform on riparian forest habitat conservation status. \u003cem\u003eBiodivers. Conserv.\u003c/em\u003e \u003cb\u003e31\u003c/b\u003e, 2141\u0026ndash;2161 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePoulsen, A. D., Tuomisto, H. \u0026amp; Balslev, H. Edaphic and floristic variation within a 1-ha plot of lowland Amazonian rain forest. \u003cem\u003eBiotropica\u003c/em\u003e \u003cb\u003e38\u003c/b\u003e, 468\u0026ndash;478 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eViana, J. L., Turner, B. L. \u0026amp; Dalling, J. W. Compositional variation in understorey fern and palm communities along a soil fertility and rainfall gradient in a lower montane tropical forest. \u003cem\u003eJ. Veg. Sci.\u003c/em\u003e \u003cb\u003e32\u003c/b\u003e, 12947. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1111/jvs.12947\u003c/span\u003e\u003cspan address=\"10.1111/jvs.12947\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLwanga, J. S., Balmford, A. \u0026amp; Badaza, R. Assessing fern diversity: Relative species richness and its environmental correlates in Uganda. \u003cem\u003eBiodivers. Conserv.\u003c/em\u003e \u003cb\u003e7\u003c/b\u003e, 1387\u0026ndash;1398 (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZuquim, G. et al. Predicting environmental gradients with fern species composition in Brazilian Amazonia. \u003cem\u003eJ. Veg. Sci.\u003c/em\u003e \u003cb\u003e25\u003c/b\u003e, 1195\u0026ndash;1207 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMessier, C., Parent, S. \u0026amp; Bergeron, Y. Effects of overstory and understory vegetation on the understory light environment in mixed boreal forests. \u003cem\u003eJ. Veg. Sci.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e, 511\u0026ndash;520 (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHill, J. D. \u0026amp; Silander, J. A. Distribution and dynamics of two ferns: \u003cem\u003eDennstaedtia punctilobula\u003c/em\u003e (Dennstaedtiaceae) and \u003cem\u003eThelypteris noveboracensis\u003c/em\u003e (Thelypteridaceae) in a Northeast mixed hardwoods\u0026ndash;hemlock forest. \u003cem\u003eAm. J. Bot.\u003c/em\u003e \u003cb\u003e88\u003c/b\u003e, 894\u0026ndash;902 (2001).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAngelini, A., Corona, P., Chianucci, F. \u0026amp; Portoghesi, L. Structural attributes of stand overstory and light under the canopy. \u003cem\u003eAnn. Silvic Res.\u003c/em\u003e \u003cb\u003e39\u003c/b\u003e, 23\u0026ndash;31. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.12899/ASR-993\u003c/span\u003e\u003cspan address=\"10.12899/ASR-993\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee, P. H., Huang, Y. M., Chiou, W. L., Tseng, Y. H. \u0026amp; Tzeng, H. Y. The correlation between fern diversity and environmental factors-case study in a Chinese Fir Plantation in Lienhuachih, central Taiwan. \u003cem\u003eTaiwan. J. Sci.\u003c/em\u003e \u003cb\u003e39\u003c/b\u003e, 271\u0026ndash;289 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeorge, L. O. \u0026amp; Bazzaz, F. A. The fern understory as an ecological filter: Growth and survival of canopy-tree seedlings. \u003cem\u003eEcology\u003c/em\u003e \u003cb\u003e80\u003c/b\u003e, 846\u0026ndash;856 (1999).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRoyo, A. A. \u0026amp; Carson, W. P. On the formation of dense understory layers in forests worldwide: Consequences and implications for forest dynamics, biodiversity, and succession. \u003cem\u003eCan. J. Res.\u003c/em\u003e \u003cb\u003e36\u003c/b\u003e, 1345\u0026ndash;1362. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1139/X06-025\u003c/span\u003e\u003cspan address=\"10.1139/X06-025\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTuomisto, H. et al. Distribution and diversity of pteridophytes and melastomataceae along edaphic gradients in Yasun\u0026iacute; National Park, Ecuadorian Amazonia. \u003cem\u003eBiotropica\u003c/em\u003e \u003cb\u003e34\u003c/b\u003e, 516\u0026ndash;533 (2002).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang, L. W., Huang, J. L., Luo, S. F. \u0026amp; Lee, P. H. Understory plant composition and its relations with environmental factors of the Lienhuachih forest dynamics plot at a subtropical evergreen broadleaf forest in central Taiwan. \u003cem\u003eTaiwan. J. Sci.\u003c/em\u003e \u003cb\u003e30\u003c/b\u003e, 245\u0026ndash;257 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFerrer-Cast\u0026aacute;n, D. \u0026amp; Vetaas, O. R. Pteridophyte richness, climate and topography in the Iberian Peninsula: Comparing spatial and nonspatial models of richness patterns. \u003cem\u003eGlob Ecol. Biogeogr.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e, 155\u0026ndash;165 (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDa Silva, V. L. \u0026amp; Schmitt, J. L. The effects of fragmentation on Araucaria forest: Analysis of the fern and lycophyte communities at sites subject to different edge conditions. \u003cem\u003eActa Bot. Brasilica\u003c/em\u003e. \u003cb\u003e29\u003c/b\u003e, 223\u0026ndash;230 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDa Silva, V. L., Mehltreter, K. \u0026amp; Schmitt, J. L. Ferns as potential ecological indicators of edge effects in two types of Mexican forests. \u003cem\u003eEcol. Indic.\u003c/em\u003e \u003cb\u003e93\u003c/b\u003e, 669\u0026ndash;676 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoufford, D. E. et al. A Checklist of the Vascular Plants of Taiwan. in \u003cem\u003eFlora of Taiwan, 2nd edition, Vol. 6\u003c/em\u003e (ed. Editorial Committee of the Flora of Taiwan, S. E.) 15\u0026ndash;139 (2003).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKuo, L. Y. et al. Updating taiwanese pteridophyte checklist: A new phylogenetic classification. \u003cem\u003eTaiwania\u003c/em\u003e \u003cb\u003e64\u003c/b\u003e, 367\u0026ndash;395 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang, L. W., Zelen\u0026yacute;, D., Li, C. F., Chiu, S. T. \u0026amp; Hsieh, C. F. Better environmental data may reverse conclusions about niche- and dispersal-based processes in community assembly. \u003cem\u003eEcology\u003c/em\u003e \u003cb\u003e94\u003c/b\u003e, 2145\u0026ndash;2151 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHill, M. TWINSPAN\u0026mdash;A fortran program for arranging multivariate data in an ordered two-way table by classification of the individuals and attributes. in Ecology and Systematics (ed University, C.) (1979). Ithaca, N. Y.) (Cornell University. Section of Ecology and Systematics.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe C\u0026aacute;ceres, M. \u0026amp; Legendre, P. Associations between species and groups of sites: Indices and statistical inference. \u003cem\u003eEcology\u003c/em\u003e \u003cb\u003e90\u003c/b\u003e, 3566\u0026ndash;3574 (2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDe C\u0026aacute;ceres, M., Legendre, P., Wiser, S. K. \u0026amp; Brotons, L. Using species combinations in indicator value analyses. \u003cem\u003eMethods Ecol. Evol.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e, 973\u0026ndash;982 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHill, M. O. \u0026amp; Gauch, H. G. Detrended correspondence analysis: An improved ordination technique. \u003cem\u003eVegetatio\u003c/em\u003e \u003cb\u003e42\u003c/b\u003e, 47\u0026ndash;58 (1980).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTer Braak, C. J. F. Canonical correspondence analysis: A new eigenvector technique for multivariate direct gradient analysis. \u003cem\u003eEcology\u003c/em\u003e \u003cb\u003e67\u003c/b\u003e, 1167\u0026ndash;1179 (1986).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eItoh, A. et al. Importance of topography and soil texture in the spatial distribution of two sympatric dipterocarp trees in a Bornean rainforest. \u003cem\u003eEcol. Res.\u003c/em\u003e \u003cb\u003e18\u003c/b\u003e, 307\u0026ndash;320 (2003).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJucker, T. et al. Topography shapes the structure, composition and function of tropical forest landscapes. \u003cem\u003eEcol. Lett.\u003c/em\u003e \u003cb\u003e21\u003c/b\u003e, 989\u0026ndash;1000 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWilcke, W. et al. Soil properties and tree growth along an altitudinal transect in Ecuadorian tropical montane forest. \u003cem\u003eJ. Plant. Nutr. Soil. Sci.\u003c/em\u003e \u003cb\u003e171\u003c/b\u003e, 220\u0026ndash;230 (2008).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang, L. W. et al. \u003cem\u003eLienhuachih Subtropical Evergreen Broadleaf Forest Dynamics Plot Tree Species Characteristics and Distribution Patterns\u003c/em\u003e (Taiwan Forestry Research Institute, 2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiang, M. et al. Research progress on the ecology of dense fern understory. \u003cem\u003eJ. Trop. Subtrop Bot.\u003c/em\u003e \u003cb\u003e30\u003c/b\u003e, 219\u0026ndash;300 (2022).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1. The\u0026nbsp;number\u0026nbsp;of subplot, relative individuals, and relative coverage for terrestrial species of fern in the one-hectare plot of the low-altitude natural forest of central Taiwan. The species doesn\u0026rsquo;t include the occurrence of 1 and 2 subplots.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"590\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003eScientific Name\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eAbbreviation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003eSubplot\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003eRelative\u0026nbsp;\u003cbr\u003e\u0026nbsp;individuals\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003eRelative\u0026nbsp;\u003cbr\u003e\u0026nbsp;coverage\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eAlsophila podophylla\u003c/em\u003e Hook.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eALSOPO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.17\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.97\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eAngiopteris lygodiifolia\u003c/em\u003e Rosenst.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eANGILY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.50\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e2.73\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eArachniodes amabilis\u003c/em\u003e (Blume) Tindale var. \u003cem\u003efimbriata\u003c/em\u003e K.Iwats\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eARACAM\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.21\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.43\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eArachniodes pseudoaristata\u003c/em\u003e (Tagawa) Ohwi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eARACPS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.81\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.43\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eBlechnopsis orientalis\u003c/em\u003e (L.) C.Presl\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eBLECOR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.01\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e4.18\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eChristella parasitica\u003c/em\u003e (L.) H.L\u0026eacute;v. \u003cem\u003eex\u003c/em\u003e Y.H.Chang\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eCHRIPA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.28\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.17\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eCibotium barometz\u003c/em\u003e (L.) J.Sm.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eCIBOBA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e3.48\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e10.71\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eDicranopteris\u003c/em\u003e \u003cem\u003elinearis\u003c/em\u003e (Burm.f.) Underw.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eDICRLI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.42\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.07\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eDiplazium dilatatum\u003c/em\u003e Blume\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eDIPLDI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e35.21\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e37.25\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eDiplazium donianum\u003c/em\u003e (Mett.) Tardieu var. \u003cem\u003eaphanoneuron\u003c/em\u003e (Ohwi) Tagawa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eDIPLAP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e6.48\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.85\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eDiplazium donianum\u003c/em\u003e (Mett.) Tardieu var. \u003cem\u003edonianum\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eDIPLDO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e10.76\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.81\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eDryopteris polita\u003c/em\u003e Rosenst.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eDRYOPO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.14\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.02\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eHymenasplenium apogamum\u003c/em\u003e (N.Murak. \u0026amp; Hatan.) Nakaike\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eHYMEAP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.78\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.71\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eHymenasplenium cheilosorum\u003c/em\u003e (Kunze ex Mett.) Tagawa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eHYMECH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.87\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.29\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eHymenasplenium\u003c/em\u003e \u003cem\u003eexcisum\u003c/em\u003e (C.Presl) S.Linds.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eHYMEEX\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e2.02\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.33\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eLeptochilus\u003c/em\u003e \u003cem\u003ehemionitideus\u003c/em\u003e (C.Presl) Noot.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLEPTHE\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.77\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.14\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eLygodium\u003c/em\u003e \u003cem\u003ejaponicum\u003c/em\u003e (Thunb.) Sw.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eLYGOJA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.31\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.71\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eMicrolepia\u003c/em\u003e \u003cem\u003ehookeriana\u003c/em\u003e (Wall. \u003cem\u003eex\u003c/em\u003e Hook.) C.Presl\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eMICRHO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.28\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.03\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eMicrolepia\u003c/em\u003e \u003cem\u003emarginata\u003c/em\u003e (Panzer) C.Chr.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eMICRMA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.38\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.08\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eMicrolepia\u003c/em\u003e \u003cem\u003eobtusiloba\u003c/em\u003e Hayata\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eMICROB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.18\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.90\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eMicrolepia\u003c/em\u003e \u003cem\u003espeluncae\u003c/em\u003e (L.) T.Moore\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eMICRSP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.10\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.24\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003ePleocnemia\u003c/em\u003e \u003cem\u003ewinitii\u003c/em\u003e Holttum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003ePLEOWI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e19.75\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e16.70\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003ePteris\u003c/em\u003e \u003cem\u003earisanensis\u003c/em\u003e Tagawa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003ePTERAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.45\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.45\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003ePteris\u003c/em\u003e \u003cem\u003edimorpha\u003c/em\u003e Copel.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003ePTERDI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.78\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.10\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003ePteris\u003c/em\u003e \u003cem\u003egrevilleana\u003c/em\u003e Wall. \u003cem\u003eex\u003c/em\u003e J. Agardh\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003ePTERGR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.35\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.01\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eSelaginella doederleinii\u003c/em\u003e Hieron.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eSELADO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.42\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.57\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eSphaerostephanos taiwanensis\u003c/em\u003e (C.Chr.) Holttum \u003cem\u003eex\u003c/em\u003e C.M.Kuo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eSPHATA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e1.78\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e7.69\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003e\u003cem\u003eTectaria simonsii\u0026nbsp;\u003c/em\u003e(Baker) Ching\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 88px;\"\u003e\n \u003cp\u003eTECTSI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 54px;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e2.58\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 77px;\"\u003e\n \u003cp\u003e0.93\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 2.\u0026nbsp;Environmental\u0026nbsp;factor models in a one-hectare natural forest plot in Lienhuachih used Poisson regression for fern richness and linear regression for fern abundance and composition (two DCA axes). Model fit was assessed using the Akaike Information Criterion (AIC), where smaller values indicate a better fit. \u0026ldquo;VIF\u0026rdquo; indicates the Variance Inflation Factor test. *: p \u0026lt; 0.05; **: p \u0026lt; 0.01; ***: p \u0026lt; 0.001.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"455\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eVariables\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 127px;\"\u003e\n \u003cp\u003eEstimate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 142px;\"\u003e\n \u003cp\u003eStandard Error\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 57px;\"\u003e\n \u003cp\u003eVIF\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eFern richness\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e[AIC: 421.16]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eElevation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0010\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0041\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.80\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eCurvature\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0068\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0144\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e2.07\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eTWI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.1374\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0927\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e2.37\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eStream distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0106\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0053\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.75\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eCa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0030\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0043\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.61\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eSapling\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0039\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0019\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.08\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eFern abundance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e[AIC: 402.7]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eElevation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0104\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0136\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eStream distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0045\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0202\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.90\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eC/N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.3507\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.2620\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.49\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eTree\u0026rsquo;s density\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0094\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0184\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eHerb \u0026amp; vine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e1.0151\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.1365\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.37\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eSapling\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0081\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0092\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.33\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eDCA1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e[AIC: 153.55]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eStream distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0038\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0052\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eC/N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.3024\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0759\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.48\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eMn\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0073\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0034\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.01\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eHerb \u0026amp; vine\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0963\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0362\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 113px;\"\u003e\n \u003cp\u003eDCA2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 14px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e[AIC: 123.01]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eElevation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0164\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e***\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0044\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e2.38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eCurvature\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0478\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0170\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e3.17\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eSlope\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.0229\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0092\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e2.30\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eTWI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.3635\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.1136\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e3.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eStream distance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0016\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0068\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e3.60\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eC/N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e0.1350\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0708\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eCa\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0030\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0042\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.74\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 130px;\"\u003e\n \u003cp\u003eTree\u0026rsquo;s density\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e-0.0066\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e0.0047\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e1.63\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 3. Indicator value analysis (IndVal) results\u0026nbsp;in the 1ha plot of Lienhuachih, the low-altitude natural forest of central Taiwan. Detail in the Supplementary.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"506\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003eSpecies\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003eA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003eB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003esqrtIV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003eGroup of DIPLDO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eDiplazium donianum\u003c/em\u003e var. \u003cem\u003edonianum\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.974\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.571\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.645\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003eGroup of DIPLAP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eDiplazium donianum\u0026nbsp;\u003c/em\u003evar.\u003cem\u003e\u0026nbsp;aphanoneuron\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.728\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.571\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.645\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003ePteris dimorpha\u003c/em\u003e var. \u003cem\u003edimorpha\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.727\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.429\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.558\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003eGroup of BLECOR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eBlechnopsis orientalis\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.833\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.913\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eSphaerostephanos taiwanensis\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.866\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003eGroup of ANGILY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eAngiopteris lygodiifolia\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.736\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.789\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.762\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eHymenasplenium apogamum\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.929\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.316\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.542\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 276px;\"\u003e\n \u003cp\u003e\u003cem\u003eHymenasplenium excisum\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.632\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e0.795\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 49px;\"\u003e\n \u003cp\u003e0.005\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n 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community, topography, soil properties, biotic factors, indicator species","lastPublishedDoi":"10.21203/rs.3.rs-6772342/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6772342/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eEnvironmental heterogeneity plays a crucial role in shaping the distribution and composition of natural vegetation, including understory ferns. As ferns are highly sensitive to environmental fluctuations, they are often regarded as effective ecological indicators. This study investigates the influence of environmental variation on understory fern communities within a one-hectare permanent plot in a low-altitude mountainous forest in central Taiwan. A total of 51 fern species (including Lycophytes), belonging to 20 families and 30 genera, were recorded. Among these, 43 were terrestrial and eight epiphytic species; however, only terrestrial species were analyzed due to limited representation of epiphytes. Multiple regression analyses identified four to eight key environmental variables influencing fern richness, abundance, and composition, with topographic factors\u0026mdash;particularly stream distance\u0026mdash;being most frequently selected. Two-way indicator species analysis (TWINSPAN) categorized the ferns into four distinct groups, while Canonical Correspondence Analysis (CCA) revealed that elevation and stream distance significantly explained compositional variation among these groups. This study underscores the role of topographic and soil-related heterogeneity in structuring fern communities and highlights potential indicator species for future ecological monitoring in subtropical forest ecosystems.\u003c/p\u003e","manuscriptTitle":"Environmental heterogeneity and its influence on fern diversity: A case study in the low-altitude mountain forest in central Taiwan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-11 09:15:27","doi":"10.21203/rs.3.rs-6772342/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-07-28T10:11:38+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-16T17:52:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"145133199719536305016106211593396678402","date":"2025-06-24T09:43:44+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-19T13:12:56+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"115473494915249398250569202251744250493","date":"2025-06-09T05:46:39+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-09T02:33:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-09T02:23:47+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-06-06T08:11:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-06T08:01:19+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-05-29T03:36:00+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"2b8d2aaf-8d3e-4fc9-8a4c-71ed4cc9d473","owner":[],"postedDate":"June 11th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":49723757,"name":"Biological sciences/Ecology"},{"id":49723758,"name":"Earth and environmental sciences/Ecology"}],"tags":[],"updatedAt":"2025-12-29T16:00:22+00:00","versionOfRecord":{"articleIdentity":"rs-6772342","link":"https://doi.org/10.1038/s41598-025-28048-9","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2025-12-23 15:57:33","publishedOnDateReadable":"December 23rd, 2025"},"versionCreatedAt":"2025-06-11 09:15:27","video":"","vorDoi":"10.1038/s41598-025-28048-9","vorDoiUrl":"https://doi.org/10.1038/s41598-025-28048-9","workflowStages":[]},"version":"v1","identity":"rs-6772342","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6772342","identity":"rs-6772342","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}