Fire-driven shifts in growth and reproduction strategies of Setaria parviflora in wetland ecosystems.

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Francielli Bao, Evaldo Benedito de Souza, Arnildo Pott, Geraldo Alves Damasceno Junior This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5059283/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 22 Jan, 2025 Read the published version in Wetlands → Version 1 posted 6 You are reading this latest preprint version Abstract Climate change and land use are intensifying wildfires in the Brazilian Pantanal, altering the dynamics of natural grasslands. Grasslands subjected to burning can experience turnover in species composition depending on fire intensity and frequency. Understanding species persistence and regeneration strategies is essential for predicting when and where fire-induced changes in plant communities may occur. Our objective was to evaluate how fire affects the seedling stage and influences survival and development, and reproductive traits. We exposed seedlings of the grass Setaria parviflora to fire and then assessed seedling performance ( e.g. , survival rate, regrowth speed) and adult plant characteristics ( e.g ., reproduction speed, seed number per spikelet) of the surviving plants compared to those of a control group without fire exposure. We also evaluated attributes related to survival, such as culm length, leaves, architecture (tillers), and roots. The survival rate was high (77%), with regrowth speed increasing after the third day post-fire. Plants that regrew after the fire had longer roots and more tillers (± 3) compared to the control group, showing significant differences. In contrast, the control group had longer culms. Regrowth attributes reflect the primary strategy for species maintenance, and despite the faster reproduction, seed production was low. Our findings suggest that fire during the seedling stage reduces the number of seeds produced, even though it enhances reproduction speed, modifies plant architecture, and increases regeneration potential through rhizomes. Fire Reproduction speed Seedling traits Survival strategies Figures Figure 1 Figure 2 Figure 3 1 INTRODUCTION In Brazil, the Pantanal stands out as a biome where fire and flooding interact uniquely, shaping vegetation and playing a crucial role in wetland fire ecology (Garcia et al., 2021 ). Seasonal cycles of floods and fires create a dynamic ecological mosaic. Fire removes aboveground biomass, stimulating vegetation regeneration, while subsequent floods provide recovery periods and redistribute nutrients (Pausas et al. 2018 ; Damasceno-Junior et al. 2022 ). Plants in these ecosystems exhibit functional traits like protected buds (e.g., Melochia parviflora ), underground rhizomes (e.g., Echinodorus longiscapus and grasses species), and thick bark (e.g., Tabebuia aurea ), enhancing their ability to resprout after fire (Damasceno-Junior et al. 2022 ). Reproductive strategies are equally vital. Some plants produce seeds with impermeable coats, ensuring viability until the next fire cycle (Gonzalez & Ghermandi 2012 ). Resprouting species focus on survival traits, while others prioritize rapid post-fire reproduction to secure reproductive success before the next disturbance (Zirondi et al. 2021 ). This strategies diversity highlights the adaptive complexity of Pantanal vegetation, where the balance between fire and flooding shapes ecological processes and supports resilience against climate change and human pressures. Functional adaptations that enhance survival in fire and flood-prone environments may be associated with low fitness and loss of competitiveness, potentially compromising survival, especially in species with fragile structures or low seed production (Westoby & Wright 2006 ). For instance, small and less robust seeds can reduce reproductive viability and increase fire vulnerability (Donohue et al. 2010 ). Rapid reproduction can be an effective strategy for habitat colonization, contributing to seed bank formation (Bao et al. 2014 ; Linder et al. 2018 ). Many species in flammable ecosystems survive for years with low seed production, leveraging their high regenerative potential provided by underground structures (Pilon et al. 2021 ). However, in environments with recurrent disturbances, such as wetland grasslands, the transition from seeds to seedlings is a critical stage. Herbaceous seedlings, for example, are particularly vulnerable due to their proximity to the soil surface, exposing them to high temperatures and fire (Williams et al. 2005 ). Additionally, some species face a high risk of reproductive failure, especially when they have only one chance to reproduce between fire cycles (Thompson & Grime 1979 ). This not only limits individual survival but can also reduce genetic variability within populations, making them less resilient to future disturbances (Oliveira & Gibbs 2002 ). These dynamics reflect the delicate balance between adaptation, regeneration, and vulnerability in ecosystems subjected to recurring fire regimes. The Brazilian Pantanal is characterized by extensive grasslands with a strong natural regeneration potential, primarily through soil seed banks, particularly following seasonal floods (2,806 ± 3,105 seeds/m²; Bao et al. 2014 ). Seeds also arrive through hydrochory from neighboring areas (Souza et al. 2016 ). However, recent rain shortages have led to prolonged droughts, and vegetation that was once shaped by floods is now facing recurrent fires (Garcia et al. 2021 ). Post-fire persistence in grasses largely depends on belowground organs, primarily short or long rhizomes, rather than stolons (Pausas & Paula 2020 ). The formation of caespitose tussocks with short rhizomes is essential for fire tolerance, while stolon and rhizomatous growth (mat-forming, as noted by Archibald et al. 2019 ) are important for grazing. The increased spread of cespitose grasses, such as Setaria parviflora , has been observed in wetlands with the rising of fires frequency (Damasceno-Junior & Pott 2022 ). Cespitose species often accumulate highly flammable aboveground biomass, which can intensify the severity and fires frequency (Pausas & Paula 2020 ). This positive feedback loop (more grasses = more fire) can transform complex ecosystems into fire-resistant monocultures, completely altering ecological dynamics. Studying the spread of grasses helps to better understand how the Pantanal responds to climate change and anthropogenic pressures, such as inadequate fire management. Thus, we raise the following questions: Does fire exposure during the seedling stage influence plant development until reaching the reproductive phase? Additionally, after a disturbance event, do plants prioritize survival and regeneration or invest in accelerated reproduction? To address these questions, we conducted a controlled experiment using Setaria parviflora (Poir.) Kerguélen, a native cespitose grass widely distributed in wetlands and recognized for its high seed production. We hypothesize that seedlings exposed to fire will exhibit greater regenerative capacity and more effective reproductive strategies compared to those not exposed. Furthermore, we expect that fire exposure will promote the development of more robust plants with enhanced reproductive performance. 2 METHODS 2.1 Key species description and seed collection area We collected seeds of S. parviflora , it is a native grass widely distributed in Brazil, with relevant economic importance as a forage in various tropical countries. This species was chosen because it is abundant in the seed banks in Brazilian Pantanal wetland (Bao et al. 2014 ), so we can observe whether there will be an effect of fire on regrowth traits until seed production. It is a perennial and caespitose fast-growing graminoid with short rhizomes and erect culm, 0.2-0.5m tall, sometimes reaching 1m at flowering. The spikelet is a spiciform cylindric panicle with persistent involucral bristles involving the deciduous spikelet (here called seeds) (Filgueiras & Rodrigues 2016 ; Souza et al. 2023). We harvested seeds from grasses in the Abobral subregion, Pantanal, Mato Grosso do Sul (Central-West of Brazil, 19º29'27,3" S; 57º01'55,9" W). Seeds were collected from different individuals located in flooded areas with different burning frequency and intensity, so all seeds have a history of fire from their matrices. The climate is tropical, and seasonal, with rainy summer and dry winter, a mean annual temperature of 26°C, and a mean annual rainfall of 1100 mm. The Pantanal is regulated by flood pulses, with river overflow lag to April-August, three months after the rains (Hamilton et al. 1996 ). September to November are critical dry periods, favoring wildfires. Local vegetation has patches with fire-prone grassland and savanna species (Pott & Silva 2015 ). We collected all seeds in plots with a fire and flood history (leading abiotic drivers in the Pantanal). 2.2 Experiment set up We put seeds to germinate, to obtain 400 seedlings, submitting 200 to fire treatment and 200 as control (without fire). We experimented in a greenhouse with ambient temperature (25ºC) at the Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Brazil. Seedlings were irrigated twice a day by suspended sprinklers. Germination was controlled and recorded for ca. one month until the seedling stage (germination data were not evaluated). Emerged seedlings had transplanted them into nursery bags half filled with latosol (Figure S1A), and later we applied the fire treatment. Experimental burns were made in the open, in the early morning ( e.g. , Whelan 1995 ). Seedlings were split into four blocks with 50 individuals to promote randomness and burned separately. Seedling bags were placed in square boxes 1m 2 , approximately 20 cm deep. Seedlings were spaced at ca. 10cm each (Figure S1A-B). The area over and between bags was filled with soil + sand so that soil bag tips stayed at the soil surface level (see Botha et al. 2020 ). A uniform fuel layer of dry grass (ca. 20cm thick/1.170kg) was spread between and over the seedlings, ensuring the fuel bed had enough aeration (Figure S1C). Burning lasted approximately 2.40 minutes (Figures S1D-E). Soil temperatures before (± 25°C) and immediately after (± 45°C) were recorded using a thermometer (Figure S1F). Immediately after burning, the seedling bags were unearthed and transferred back to the greenhouse. In the experiment, we retained all fire residues on the bags to avoid nutrient loss resulting from fire (see Lavorel & Garnier 2002), approaching the actual field conditions. 2.3 Traits immediately after fire First, after applying the burning treatment, the regrowth potential was evaluated by regrowth speed, where we considered the initial time (first day) the day after the fire and the final time (last day) when the first tiller emerged (green part); evaluation of the regrowth time lasted ca. 30 days. We considered tillering (architecture) also a regrowth attribute (Pérez-Harguindeguy et al. 2013 ) (Table 1 ). It is noteworthy that we did not consider the occurrence of defoliation without burning, to have a control experiment. Table 1 List of attributes measured in adult plants of Setaria parviflora in both treatments: post-fire and without fire (control). Attributes Objectives Data collection and evaluation method Control Post-fire References Root length Assess survival and fitness potential. Pachymeter (mm). Yes Yes Larson et al., 2015 Leaves number Assess fitness. Continuous count Yes Yes Botha et al., 2020 Total length Assess survival and fitness potential. Pachymeter (mm). Yes Yes Larson et al., 2015 Culm diameter Assess survival and fitness potential. Pachymeter (mm), from 1 cm above the ground. Yes Yes Wigley et al ., 2021 Side branches Evaluate architectural changes due to fire exposure. Continuous count. No Yes Pérez-Harguindeguy et al., 2013 ; Botha et al., 2020 Resprouting ratio speed Assess resprout potential. Continuous Count per day. No Yes Pérez-Harguindeguy et al., 2013 Survival rate Assess survival rate. Percentage (%). No Yes Botha et al., 2020 Flowering ratio speed Assess reproductive potential. Continuous count per day. Yes Yes Wigley et al., 2020 Seeds number Assess reproductive potential. Continuous count. Yes Yes Benvenuti, 2007 >>>Table 1 2.4 Traits in the reproductive stage We monitored seedling development in regrown plants until they reached the reproduction stage (spikelet emission) and evaluated the functional traits in all plants from both the post-fire and control (no fire) treatments (Table 1 ). We assessed the reproductive attribute "reproduction speed" by conducting daily counts of all surviving plants in the post-fire group and those in the control group. For the post-fire group, the initial time point was the start of regrowth (first tiller emergence), and the final time point was spikelet emission. In the control group, the initial time point was the first day of germination (coleoptile emergence), and the final time point was also spikelet emission. For all plants that reproduced, we recorded the number of seeds produced per spikelet. To evaluate fitness in terms of reproductive aspects, we measured growth traits at the end of the experiment (once reproduction occurred). These traits included total plant height, culm diameter and height, number of leaves, and root length ( e.g. , Botha et al. 2020 ; Larson et al. 2015 ) (Table 1 ). Plants in the control group remained in the greenhouse throughout the entire experimental period. 2.5 Data analyses To verify if fire affects the reproduction speed, we made analyses of survival curves through the non-parametric estimator Kaplan-Meier (Kaplan & Meier 1958 ), with the survfit function of the package survival (Therneau 2015 ). The survival curves of both groups (post-fire vs. control) were compared through the log-rank test (or Mantel-Haenszel test) (Harrington & Fleming 1982 ), applying the function survdiff. The log-rank test calculates a Chi-Square (χ 2 ) value for all events in each group and sums the results. The sum of these results for each group are utilized to generate a χ 2 to compare the full curves of each group. The curves also can visually be compared by plotting confidence intervals. Non-overlapping confidence intervals indicate significant difference between curves. The survival graph was presented with inverted curves for better observation reproduction ratio speed. We used Shapiro-Wilk test to test the normality of each treat and Levene test to variance homogeneity. To assess the responses of the traits to fire, because all traits have a normal or approximately normal distribution, we utilized Linear mixed models (LMM). Because of heteroscedasticity, we specified the within-groups variance structure in the model. We set the four lots per treatment as a random effect for the model intercept. The model assumptions were acceded by diagnostic plots (fitted versus residuals). Besides, to evaluate the effect of fire on the variability of traits, we calculated the coefficient of variation (CV) of traits in each treatment. All statistical analyses were performed using the program R packages (R Core Team 2023 ). 3 RESULTS 3.1 Seedling survival rate and regrowth traits The seedling survival rate was 77% in the post-fire group. The regrowth speed was 6.4 seedlings/day, recorded between the 3r d and 14th day (Fig. 1 A). Despite the whole aerial part having been burned, regrowth started from the return of the main culm (Fig. 1 B) and the emergence of tillers (Fig. 1 C). We did not find the tillering in the control group. >>> Fig. 1 The culm length of the control was twice longer (mean = 333.83 ± 56 mm) that of the post-fire (176.16 ± 18.69 mm) (Fig. 2 A samples). In the post-fire group, seedlings invested more in the culm diameter (1.18 ± 0.22 mm) and root length (163.19 ± 10.24 mm) than in the control (Fig. 2 B-C). In contrast, full plant height had a higher mean in the control (482.78 ± 61.55 mm) due to culm length (Fig. 2 D). The leaf number per branch was higher in the control than in post-fire treatment (Table S1; Fig. 2 E). From the coefficient of variation, we also observed that fire determines a homogeneous response (meaning lower variation) of the attribute’s culm length, root length, total height, and seed number (Figure S2). In the traits of culm diameter and leaf number, the coefficient of variance was lower in the control (Figure S2). >>> Fig. 2 3.2 Reproductive traits All plants produced seeds in both treatments. The reproduction ratio in the post-fire group was higher between the 6th and 16th day. Based on the difference between the survival curves, reproduction was significantly different between treatments (χ 2 = 164; p < 0.001; Fig. 3 ). We observed that with fire, most plants (44) reproduced themselves within a short period homogeneously between 7th and 10th day, while in the control, reproduction was relatively heterogeneous between the 10th and 30th day, with peaks on days 22 and 23 (Table 2 ). However, the number of seeds per spikelet/plant was drastically reduced in the post-fire (ca. 16) compared with the control (ca. 60) (Fig. 2 F). Table 2 Log-Rank Mantel-Haenszel test for Kaplan-Meier estimates between control and post-fire treatments. Treatment N O E (O-E) ^2/E (O-E) ^2/V Control 200 200 151.5 17.5 164 Post-fire 200 144 25.5 104.2 164 N = total number of seedlings per treatment, O = Observed, E = expected, and V = variance. Supplementary table 1. Mean and standard deviation (Sd) of Setaria parviflora attributes per treatment (control - C and post-fire - F). >>> Fig. 3 >>> Table 2 4 DISCUSSION 4.1 Seedling survival rate The survival rate of Setaria parviflora seedlings after fire was remarkably high, especially considering that small plants, being close to the ground, are typically more vulnerable to damage caused by high temperatures. This pattern reflects significant adaptations of grasses in fire-prone ecosystems. For instance, underground structures such as rhizomes and stolons are critical for post-fire survival and recovery after intense grazing, as observed in tropical grasses (Gittins et al. 2011 ). Comparatively, grasses from other flammable ecosystems, such as Cenchrus ciliaris in African savannas, exhibit similar survival strategies, relying on underground storage structures and rapid vegetative regeneration (Miller et al. 2010 ). Conversely, herbaceous plants in temperate grasslands often depend on heat-resistant seeds to persist under intense fire regimes (Larson & Funk 2016 ). This diversity of strategies highlights how fire adaptations vary among species and habitats, shaping the composition and resilience of plant communities. Fire intensity and frequency also play critical roles. High-intensity fires can elevate soil temperatures to levels that compromise underground structures, even in grasses with deep rhizomes (Ramsay & Oxley 1996 ). Studies on Andropogon gerardii and other prairie grasses have shown that less frequent fires allow the recovery of underground reserves, whereas recurrent fires can deplete plants' regenerative capacity (Kimball et al. 2016 ). Thus, although S. parviflora demonstrated high survival rates in the present study, its response likely varies significantly depending on fire intensity and frequency. Furthermore, the plant’s life stage directly influences its ability to withstand fire. Young seedlings and plants in early developmental stages are generally more vulnerable, while mature plants with more developed underground systems exhibit greater resilience (Archibald et al. 2019 ; Larson et al. 2020 ). In the case of S. parviflora, the initiation of rhizome development during the seedling stage may have contributed to the observed 77% survival rate, underscoring the importance of this trait for the species' persistence in environments subject to extreme disturbances. Understanding how different fire intensities affect seedling survival and the development of grasses such as S. parviflora is essential for comprehending plant regeneration dynamics in flammable ecosystems. This knowledge not only aids in predicting changes in vegetation composition under altered fire regimes but also provides critical insights for management and conservation strategies, particularly in tropical wetlands like the Pantanal. 4.2 Regrowth traits The regrowth speed observed from the third day after the fire reinforces the idea that fire acts as a key driver in the dynamics of the herbaceous layer, as previously suggested in other studies (Parrini & Owen-Smith 2010 ). This response indicates that traits promoting fire resilience, such as regenerative capacity, are already present during the early stages of development. Plants adapted to fire-prone environments often possess underground structures, such as rhizomes and storage organs, which play a critical role in vegetation regeneration and resilience (Fidelis et al. 2014; Le Stradic et al. 2020). These attributes result from selective pressures in environments with recurring fires, leading some species to evolve as "resprouters" (Lamont & Downes 2011 ; Pausas & Keeley 2014 ; Pausas et al. 2018 ). However, further studies are needed to understand the long-term impacts of fire management on seedlings. In our study, regeneration was initiated by both the main culm and tillers, with fire clearly inducing changes in plant architecture. While the control group showed no evidence of tillering, fire-exposed plants exhibited uniform post-fire tillering. This response suggests that fire not only triggers regeneration but also directly influences plant morphology. Architectural changes, such as an increase in extravaginal tillering, can lead to more decumbent lateral colonization strategies, reducing plant height (Briske 1991 ). This reduction may have important implications, such as decreased attractiveness to herbivory in areas with shorter grasses (Pfeiffer & Hartnett 1995 ). Moreover, increased tillering can result in a higher number of inflorescences, potentially altering population dynamics and plant community composition in savanna ecosystems. Comparisons with other species in the same ecosystem provide further insights into differential fire responses. For example, grasses such as Andropogon bicornis , also common in savanna and wetland areas, show rapid post-fire regeneration but tend to maintain greater height (Damasceno-Júnior et al. 2022), making them more attractive to herbivory (Hoffmann & Moreira 2002). In contrast, invasive grass species like Urochloa brizantha rely more heavily on seed-based regeneration and tend to increase in dominance following frequent fires, potentially excluding native species (Vilà et al. 2001 ). These comparisons highlight how S. parviflora combines post-fire tillering and the development of longer roots as strategies to persist in disturbance-prone environments. Additionally, changes in plant architecture can influence interspecific competition and population regeneration processes. The reduced height of fire-exposed plants may favor taller competing species, altering plant community structure (Archibald & Bond 2003 ). However, the increased root length observed in fire-exposed plants offers competitive advantages in resource uptake, especially in stressed environments. Longer roots are often associated with greater capacity for water and nutrient extraction, traits essential in wetland ecosystems subjected to fire and drought cycles (Le Stradic et al. 2020). The structural changes observed, such as reduced culm length in burned plants and increased root length, have direct implications for vegetation resilience and community composition. In areas prone to grass invasions, the relationship between abundance and fire regimes can amplify the risk of recurring fires, favoring invasive species at the expense of native ones (Vilà et al. 2001 ). Understanding how fire alters the architecture of species like S. parviflora is crucial for predicting dominance patterns and designing effective management and conservation strategies. Finally, even at early stages such as seedlings, S. parviflora exhibited adaptive traits that ensured a relatively high survival rate. The development of longer roots and the presence of tillers contributed to its resilience and post-fire regrowth. These responses underscore the importance of studies that consider different fire intensities and frequencies, as well as their impacts on coexisting species, to fully comprehend the dynamics of regeneration in ecosystems subject to extreme disturbances, such as the Pantanal. 4.3 Reproductive traits All regrowth individuals produced reproductive structures, and our study found that fire accelerated the rate of reproduction. Previous field studies, such as those on certain sedges ( Bulbostylis paradoxa , Rhynchospora confusa , and R. terminalis ), have shown that flowering can occur within 24 hours after fire (Fidelis et al. 2019 ; Pilon et al. 2021 ). Fast reproduction is a strategy to rapidly disperse a high number of seeds within a short recruitment window (Zirondi et al. 2021 ). However, our study indicated that although fire increased the reproduction speed, it significantly reduced the number of seeds produced per individual. This reduction can be attributed to the fact that plants, particularly in early developmental stages, prioritize regrowth and establishment over high resource allocation to reproduction. Thus, the observed fast reproduction may not necessarily correlate with effective seed production and dispersal, raising questions about long-term population sustainability. Reproductive dynamics play a crucial role in genetic diversity and population success. In species such as S. parviflora , fast reproductive events after fire may promote cross-pollination among nearby populations due to flowering synchronization, enhancing genetic variability (Wright et al. 2022 ). On the other hand, reduced seed production per individual may limit long-distance dispersal, restricting the colonization of new habitats and favoring genetically more homogeneous populations. This limitation may be partially offset by the increase in post-fire tillering, which can lead to a greater number of spikelets per individual over time (Keeley et al. 2011 ). Higher spikelet production may contribute to the maintenance of local populations, although its impact on the structure of plant communities still requires investigation. Historically, open savanna ecosystems often exhibit more flowering in burned areas compared to unburned areas (Fidelis & Blanco 2014 ). This difference is influenced by the plants' ability to rapidly allocate resources to reproduction after the removal of aerial biomass, when competition for light is reduced and the availability of soil nutrients increases (Keeley et al. 2011 ). Moreover, the fire regime plays a critical role in shaping reproductive strategies (Fidelis et al. 2019 ). Factors such as fire frequency, intensity, and seasonality can influence the ability of plants to combine vegetative propagation strategies with seed production and dispersal (Lamont et al. 2019 ). Frequent fire regimes may favor species with high resilience and rapid reproductive strategies but may disadvantage species requiring longer intervals between disturbances to accumulate energy reserves and produce a larger seed yield. Environmental conditions, such as water availability, nutrients, and light intensity, also directly influence post-fire reproductive success (Pyke 2017 ). In wetlands areas like the Pantanal, seasonal changes and drought cycles may interact with fire regimes, altering the conditions for germination and establishment of new plants (Soares et al. 2021 ). These interactions are critical in determining the composition of plant communities and may favor species with a greater capacity to adapt to multiple disturbances. Our findings demonstrate that this species exhibits resilience and versatility in response to disturbances such as fire. Despite its high seed dispersal capacity and role in pasture regeneration through seed banks (Bao et al. 2014 ), the species also shows significant potential for regrowth, even when fire occurs at an early developmental stage. However, further studies are needed to understand how reproductive strategies influence population dynamics and genetic diversity in the long term, especially in the context of climate change, which may intensify fire regimes and alter the environmental conditions these species inhabit. 4.4 Structural Implications in Grasslands Regarding the main questions driving this study, the fire occurrence during the seedling stage significantly impacts plant development up to reproduction. The plant tends to allocate more resources to traits associated with regrowth and persistence, such as root length and tiller production. Despite exhibiting a higher reproduction rate, S. parviflora showed a reduction in seed production compared to the control group. This pattern suggests that, at early developmental stages, the plant prioritizes strategies that enhance its resilience and immediate survival over a high allocation of resources to reproduction. However, our study did not evaluate subsequent reproductive phases, such as the number of spikelets per culm, nor did it test seed viability. Therefore, traits related to regrowth provided a more comprehensive understanding of ecological colonization strategies than purely reproductive characteristics. Previous studies indicate that changes in fire regimes can drastically affect colonization strategies and the maintenance of grasses in wetland ecosystems. Our findings suggest that even after a single fire event, the disturbance regime can alter plant architecture, promoting increased tillering and resulting in shorter, more branched individuals. These traits may enhance individual persistence through the development of underground structures, such as rhizomes, while potentially reducing population regeneration via the seed bank. This reduction may limit the species' expansion in the Pantanal but could also contribute to the stability of local populations in contexts of high resource competition. Contextualizing these results, it is possible to extrapolate that the versatility of S. parviflora in responding to fire and other disturbances positions it as a species well-adapted to a wide range of ecological scenarios. This adaptability has implications not only for the structure and composition of local plant communities but also for management strategies in wetland ecosystems vulnerable to invasions and alterations in disturbance regimes. Future studies should further investigate seed viability, the impacts of long-term fire regimes, and competitive interactions in natural communities to better understand the ecological role and potential threats associated with S. parviflora and other grasses. 5 CONCLUSIONS Regrowth traits reflect the primary strategy of the species maintenance, and, despite fast reproduction, seed production was low. Our findings indicate that seedlings of the model species ( S. parviflora ) are capable of withstanding fire exposure, leading to changes in plant produced tillers and increased regeneration potential through rhizomes. These adaptations, although effective for individual persistence, may lead to a reduction in the species' seed bank, which, in turn, could negatively affect long-term population regeneration. Based on these findings, it is essential to consider the potential ecological impacts and implications for managing grasslands subjected to frequent fire regimes. Management strategies could focus on balancing the need to maintain the seed bank with preserving species resilience to disturbances, ensuring both long-term regeneration and the stability of the plant community. Declarations AUTHORS CONTRIBUTION Conceptualization – FB; Funding acquisition – GADJ; Investigation – FB, GADJ; Supervision – GADJ; Writing – Original Draft – FB, EBS, AP, GADJ; Writing – Review & Editing – FB, EBS, AP, GADJ; Visualization – FB, EBS, AP, GADJ. DECLARATION OF COMPETING INTEREST The authors declare that they have no known competing financial interests or personal relationships that could influence this paper. DATA AVAILABILITY Data will be made available on request. This work was supported by the PELD Program (CNPq process 445354/2020-8; FUNDECT 427/2021), Instituto de Meio Ambiente de Mato Grosso do Sul (IMASUL TF 001/2022), and MCTI - Pantanal Research Network (grant number: FINEP: 01.20.0201.00). 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Funct Ecol 34: 968-979. Le Stradic S, Roumet C, Durigan G, Cancian L, Fidelis A (2021) Variation in biomass allocation and root functional parameters in response to fire history in Brazilian savannas. J Ecol 109: 4143-4157. Linder HP, Lehmann CE, Archibald S, Osborne CP, Richardson DM (2018) Global grass (Poaceae) success underpinned by traits facilitating colonization, persistence and habitat transformation. Biol Rev 93: 1125-1144. Miller G, Friedel M, Adam P, Chewings V (2010) Ecological impacts of buffel grass ( Cenchrus ciliaris L.) invasion in central Australia–does field evidence support a fire-invasion feedback?. Rangeland J 32: 353-365. Oliveira PE, Gibbs PE (2002) Pollination and reproductive biology in cerrado plant communities. In: Oliveira PE, Marquis RJ eds. The cerrados of Brazil: Ecology and Natural History of a Neotropical Savanna. New York: Columbia University. Parrini F, Owen‐Smith N (2010) The importance of post‐fire regrowth for sable antelope in a Southern African savanna. Afr J Ecol 48: 526-534. Pausas JG, Keeley JE (2014) Evolutionary ecology of resprouting and seeding in fire‐prone ecosystems. New Phytol 204: 55-65. Pausas JG, Lamont BB, Paula S, Appezzato‐da‐Glória B, Fidelis A (2018) Unearthing belowground bud banks in fire‐prone ecosystems. New Phytol 217: 1435-1448. Pausas JG, Paula S (2020) Grasses and fire. New Phytol 226: 957-959. Pérez-Harguindeguy N, Díaz S, Garnier E et al (2013) New handbook for standardised measurement of plant functional traits worldwide. Aust J Bot 61: 167-234. Pfeiffer KE, Hartnett DC (1995) Bison selectivity and grazing response of little bluestem in tallgrass prairie. J Range Manag 48: 26-31. Pilon NA, Cava MG, Hoffmann WA, Abreu RC, Fidelis A, Durigan G (2021) The diversity of post‐fire regeneration strategies in the Cerrado ground layer. J Ecol 109: 154-166. Pott A, Silva JSV (2015) Terrestrial and aquatic vegetation diversity of the Pantanal wetland in: Bergier I, Assine ML (Eds.), Dynamics of the Pantanal Wetland in South America. Handb. Environ. Chem Lett 37: 111-131. Pyke GH (2017) Fire-stimulated flowering: a review and look to the future. Crit Rev Plant Sci 36: 179-189. R Core Team (2023) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available at http://www.R-project.org Ramsay PM, Oxley ERB (1996) Fire temperatures and postfire plant community dynamics in Ecuadorian grass páramo. Plant Ecol 124: 129-144. Soares VC, Scremin-Dias E, Daibes LF, Damasceno-Junior GA, Pott A, Lima LB (2021) Fire has little to no effect on the enhancement of germination, but buried seeds may survive in a Neotropical wetland. Flora 278: 151801. Souza EB, Ferreira FA, Pott A (2016) Effects of flooding and its temporal variation on seedling recruitment from the soil seed bank of a Neotropical floodplain. Acta Bot Brasilica 31: 64-75. Sousa VF, Santos CAG, Boldrini II (2023) Setaria in Flora e Funga do Brasil. Jardim Botânico do Rio de Janeiro. Available at https://floradobrasil.jbrj.gov.br/FB13588. Access in 18 jun 2023. Therneau T (2015) A package for survival analysis in S. R package version . 2: 7. Thompson K, Grime JP (1979) Seasonal variation in the seed banks of herbaceous species in ten contrasting habitats. J Ecol 15: 893-921. Vilà M, Lloret F, Ogheri E, Terradas J (2001) Positive fire–grass feedback in Mediterranean Basin woodlands. For Ecol Manage 147: 3-14. Westoby M, Wright IJ (2006) Land-plant ecology based on functional traits. Trends Ecol Evol 21: 261-268. Whelan RJ (1995) The Ecology of Fire. Cambridge: Cambridge University Press. 346p. Wigley BJ, Charles-Dominique T, Hempson GP et al (2020) A handbook for the standardised sampling of plant functional traits in disturbance-prone ecosystems, with a focus on open ecosystems. Aust J Bot 68: 473-531. Williams PR, Congdon RA, Grice AC, Clarke PJ (2005) Effect of season of burning and removal of herbaceous cover on seedling emergence in a eucalypt savanna of north‐eastern Australia. Austral Ecol 30: 491-496. Wright BR, Franklin DC, Fensham RJ (2022) The ecology, evolution and management of mast reproduction in Australian plants. Austral J Bot 70: 509-530. Zirondi HL, Ooi MKJ, Fidelis A (2021) Fire-triggered flowering is the dominant post-fire strategy in a tropical savanna. J Veg Sci 32: e12995. Supplementary Files supplementaryfigure.docx Cite Share Download PDF Status: Published Journal Publication published 22 Jan, 2025 Read the published version in Wetlands → Version 1 posted Editorial decision: Accept 13 Jan, 2025 Editor assigned by journal 09 Jan, 2025 Reviewers agreed at journal 10 Dec, 2024 Reviewers invited by journal 05 Dec, 2024 Editor invited by journal 05 Dec, 2024 First submitted to journal 04 Dec, 2024 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. We do this by developing innovative software and high quality services for the global research community. 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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-5059283","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":386585533,"identity":"b2bf3d7f-4387-4e98-984f-e3444b785ef6","order_by":0,"name":"Francielli Bao","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1UlEQVRIiWNgGAWjYBAC9gYGBmYgLcfAwAMT48GtHCx9AKLFmHQtiQ3Ea5E+/OxxQY1N+objZw8++MBgJ6fbwHvsA14tfGnmxjOOpeVuOJOXbDiDIdnY7ABf8gx8Wux5GMykedgO5244kANkMBxI3HaAxxi/w3jYv0nz/DucbnD+DdFaeMykedsOJxjcIN4WnjLpmX1phjNvvDE2nGEA9MthvmRCDtsmXfDNRp7vfI7hgw8VdnJmx3sP49UCBwoHQKQBAySaiALyDcSqHAWjYBSMghEHADfWQVfQ4s1mAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0003-0536-1668","institution":"Universidade Federal de Mato Grosso do Sul","correspondingAuthor":true,"prefix":"","firstName":"Francielli","middleName":"","lastName":"Bao","suffix":""},{"id":386585534,"identity":"bca7cafa-84ad-4000-83f5-9b7e36415acd","order_by":1,"name":"Evaldo Benedito de Souza","email":"","orcid":"","institution":"Universidade Federal de Mato Grosso do Sul","correspondingAuthor":false,"prefix":"","firstName":"Evaldo","middleName":"Benedito","lastName":"de Souza","suffix":""},{"id":386585537,"identity":"4c7d2a27-6c6a-4aeb-805a-b4f0d4704a79","order_by":2,"name":"Arnildo Pott","email":"","orcid":"","institution":"Universidade Federal de Mato Grosso do Sul","correspondingAuthor":false,"prefix":"","firstName":"Arnildo","middleName":"","lastName":"Pott","suffix":""},{"id":386585538,"identity":"7ede7f0f-53d4-4bb9-9a74-2efb18f95fbe","order_by":3,"name":"Geraldo Alves Damasceno Junior","email":"","orcid":"","institution":"Universidade Federal de Mato Grosso do Sul","correspondingAuthor":false,"prefix":"","firstName":"Geraldo","middleName":"Alves Damasceno","lastName":"Junior","suffix":""}],"badges":[],"createdAt":"2024-09-09 16:01:03","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5059283/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5059283/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s13157-025-01903-1","type":"published","date":"2025-01-22T15:57:47+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":70738817,"identity":"e7e4b1fd-a180-48e7-82bd-b7a261f07d64","added_by":"auto","created_at":"2024-12-06 07:18:31","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":93693,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eA\u003c/strong\u003e Kaplan-Meier resprouting curve for \u003cem\u003eSetaria parviflora\u003c/em\u003e regrowth ratio post-fire. Shaded areas represent 95% confidence intervals. \u003cstrong\u003eB\u003c/strong\u003e \u003cem\u003eS. parviflora\u003c/em\u003e regrowth from the return of the main culm (3r\u003csup\u003ed \u003c/sup\u003eday post-fire). \u003cstrong\u003eC\u003c/strong\u003e Emergence of tillers (10\u003csup\u003eth \u003c/sup\u003eday post-fire).\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5059283/v1/2f465a5d781b3b7e0b4e4329.jpg"},{"id":70738818,"identity":"3abe6587-6700-4222-a1a4-93431ef6f5c3","added_by":"auto","created_at":"2024-12-06 07:18:31","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":72512,"visible":true,"origin":"","legend":"\u003cp\u003eBoxplots comparing the attribute values between the control and post-fire treatments. The F-values and significance levels (p \u0026lt; 0.05) are indicated for each trait.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5059283/v1/6a377746400a10f32adbce8a.jpg"},{"id":70737682,"identity":"face48d6-e593-45fd-9528-56eb1866bf03","added_by":"auto","created_at":"2024-12-06 07:02:31","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":39124,"visible":true,"origin":"","legend":"\u003cp\u003eLog-rank test on the Kaplan-Meier survival curves for comparison of \u003cem\u003eSetaria parviflora\u003c/em\u003e flowering between control and post-fire treatments. Shaded areas represent 95% confidence intervals.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5059283/v1/a2771ed40a9e43e7d23c8c80.jpg"},{"id":74858424,"identity":"e9ab6717-5b49-4071-aaf2-80ee7ed6b456","added_by":"auto","created_at":"2025-01-27 16:09:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":912528,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5059283/v1/3fcefcb8-e620-4d4f-bb30-4432ca9b4bb3.pdf"},{"id":70738653,"identity":"916fa426-ee32-4516-b5c4-44f545d362ae","added_by":"auto","created_at":"2024-12-06 07:10:31","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":459414,"visible":true,"origin":"","legend":"","description":"","filename":"supplementaryfigure.docx","url":"https://assets-eu.researchsquare.com/files/rs-5059283/v1/74f72226e2b94c8d4e9a95ab.docx"}],"financialInterests":"","formattedTitle":"Fire-driven shifts in growth and reproduction strategies of Setaria parviflora in wetland ecosystems.","fulltext":[{"header":"1 INTRODUCTION","content":"\u003cp\u003eIn Brazil, the Pantanal stands out as a biome where fire and flooding interact uniquely, shaping vegetation and playing a crucial role in wetland fire ecology (Garcia et al., \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Seasonal cycles of floods and fires create a dynamic ecological mosaic. Fire removes aboveground biomass, stimulating vegetation regeneration, while subsequent floods provide recovery periods and redistribute nutrients (Pausas et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Damasceno-Junior et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Plants in these ecosystems exhibit functional traits like protected buds (e.g., \u003cem\u003eMelochia parviflora\u003c/em\u003e), underground rhizomes (e.g., \u003cem\u003eEchinodorus longiscapus\u003c/em\u003e and grasses species), and thick bark (e.g., \u003cem\u003eTabebuia aurea\u003c/em\u003e), enhancing their ability to resprout after fire (Damasceno-Junior et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eReproductive strategies are equally vital. Some plants produce seeds with impermeable coats, ensuring viability until the next fire cycle (Gonzalez \u0026amp; Ghermandi \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Resprouting species focus on survival traits, while others prioritize rapid post-fire reproduction to secure reproductive success before the next disturbance (Zirondi et al. \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). This strategies diversity highlights the adaptive complexity of Pantanal vegetation, where the balance between fire and flooding shapes ecological processes and supports resilience against climate change and human pressures.\u003c/p\u003e \u003cp\u003eFunctional adaptations that enhance survival in fire and flood-prone environments may be associated with low fitness and loss of competitiveness, potentially compromising survival, especially in species with fragile structures or low seed production (Westoby \u0026amp; Wright \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). For instance, small and less robust seeds can reduce reproductive viability and increase fire vulnerability (Donohue et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Rapid reproduction can be an effective strategy for habitat colonization, contributing to seed bank formation (Bao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Linder et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Many species in flammable ecosystems survive for years with low seed production, leveraging their high regenerative potential provided by underground structures (Pilon et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, in environments with recurrent disturbances, such as wetland grasslands, the transition from seeds to seedlings is a critical stage. Herbaceous seedlings, for example, are particularly vulnerable due to their proximity to the soil surface, exposing them to high temperatures and fire (Williams et al. \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2005\u003c/span\u003e). Additionally, some species face a high risk of reproductive failure, especially when they have only one chance to reproduce between fire cycles (Thompson \u0026amp; Grime \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e1979\u003c/span\u003e). This not only limits individual survival but can also reduce genetic variability within populations, making them less resilient to future disturbances (Oliveira \u0026amp; Gibbs \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). These dynamics reflect the delicate balance between adaptation, regeneration, and vulnerability in ecosystems subjected to recurring fire regimes.\u003c/p\u003e \u003cp\u003eThe Brazilian Pantanal is characterized by extensive grasslands with a strong natural regeneration potential, primarily through soil seed banks, particularly following seasonal floods (2,806\u0026thinsp;\u0026plusmn;\u0026thinsp;3,105 seeds/m\u0026sup2;; Bao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Seeds also arrive through hydrochory from neighboring areas (Souza et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). However, recent rain shortages have led to prolonged droughts, and vegetation that was once shaped by floods is now facing recurrent fires (Garcia et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Post-fire persistence in grasses largely depends on belowground organs, primarily short or long rhizomes, rather than stolons (Pausas \u0026amp; Paula \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The formation of caespitose tussocks with short rhizomes is essential for fire tolerance, while stolon and rhizomatous growth (mat-forming, as noted by Archibald et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) are important for grazing.\u003c/p\u003e \u003cp\u003eThe increased spread of cespitose grasses, such as \u003cem\u003eSetaria parviflora\u003c/em\u003e, has been observed in wetlands with the rising of fires frequency (Damasceno-Junior \u0026amp; Pott \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Cespitose species often accumulate highly flammable aboveground biomass, which can intensify the severity and fires frequency (Pausas \u0026amp; Paula \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). This positive feedback loop (more grasses\u0026thinsp;=\u0026thinsp;more fire) can transform complex ecosystems into fire-resistant monocultures, completely altering ecological dynamics. Studying the spread of grasses helps to better understand how the Pantanal responds to climate change and anthropogenic pressures, such as inadequate fire management.\u003c/p\u003e \u003cp\u003eThus, we raise the following questions: Does fire exposure during the seedling stage influence plant development until reaching the reproductive phase? Additionally, after a disturbance event, do plants prioritize survival and regeneration or invest in accelerated reproduction? To address these questions, we conducted a controlled experiment using \u003cem\u003eSetaria parviflora\u003c/em\u003e (Poir.) Kergu\u0026eacute;len, a native cespitose grass widely distributed in wetlands and recognized for its high seed production. We hypothesize that seedlings exposed to fire will exhibit greater regenerative capacity and more effective reproductive strategies compared to those not exposed. Furthermore, we expect that fire exposure will promote the development of more robust plants with enhanced reproductive performance.\u003c/p\u003e"},{"header":"2 METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Key species description and seed collection area\u003c/h2\u003e \u003cp\u003eWe collected seeds of \u003cem\u003eS. parviflora\u003c/em\u003e, it is a native grass widely distributed in Brazil, with relevant economic importance as a forage in various tropical countries. This species was chosen because it is abundant in the seed banks in Brazilian Pantanal wetland (Bao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), so we can observe whether there will be an effect of fire on regrowth traits until seed production. It is a perennial and caespitose fast-growing graminoid with short rhizomes and erect culm, 0.2-0.5m tall, sometimes reaching 1m at flowering. The spikelet is a spiciform cylindric panicle with persistent involucral bristles involving the deciduous spikelet (here called seeds) (Filgueiras \u0026amp; Rodrigues \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Souza et al. 2023).\u003c/p\u003e \u003cp\u003eWe harvested seeds from grasses in the Abobral subregion, Pantanal, Mato Grosso do Sul (Central-West of Brazil, 19\u0026ordm;29'27,3\" S; 57\u0026ordm;01'55,9\" W). Seeds were collected from different individuals located in flooded areas with different burning frequency and intensity, so all seeds have a history of fire from their matrices. The climate is tropical, and seasonal, with rainy summer and dry winter, a mean annual temperature of 26\u0026deg;C, and a mean annual rainfall of 1100 mm. The Pantanal is regulated by flood pulses, with river overflow lag to April-August, three months after the rains (Hamilton et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). September to November are critical dry periods, favoring wildfires. Local vegetation has patches with fire-prone grassland and savanna species (Pott \u0026amp; Silva \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). We collected all seeds in plots with a fire and flood history (leading abiotic drivers in the Pantanal).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Experiment set up\u003c/h2\u003e \u003cp\u003eWe put seeds to germinate, to obtain 400 seedlings, submitting 200 to fire treatment and 200 as control (without fire). We experimented in a greenhouse with ambient temperature (25\u0026ordm;C) at the Federal University of Mato Grosso do Sul (UFMS), Campo Grande, Brazil. Seedlings were irrigated twice a day by suspended sprinklers. Germination was controlled and recorded for ca. one month until the seedling stage (germination data were not evaluated). Emerged seedlings had transplanted them into nursery bags half filled with latosol (Figure S1A), and later we applied the fire treatment. Experimental burns were made in the open, in the early morning (\u003cem\u003ee.g.\u003c/em\u003e, Whelan \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e1995\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eSeedlings were split into four blocks with 50 individuals to promote randomness and burned separately. Seedling bags were placed in square boxes 1m\u003csup\u003e2\u003c/sup\u003e, approximately 20 cm deep. Seedlings were spaced at ca. 10cm each (Figure S1A-B). The area over and between bags was filled with soil\u0026thinsp;+\u0026thinsp;sand so that soil bag tips stayed at the soil surface level (see Botha et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). A uniform fuel layer of dry grass (ca. 20cm thick/1.170kg) was spread between and over the seedlings, ensuring the fuel bed had enough aeration (Figure S1C). Burning lasted approximately 2.40 minutes (Figures S1D-E). Soil temperatures before (\u0026plusmn;\u0026thinsp;25\u0026deg;C) and immediately after (\u0026plusmn;\u0026thinsp;45\u0026deg;C) were recorded using a thermometer (Figure S1F). Immediately after burning, the seedling bags were unearthed and transferred back to the greenhouse. In the experiment, we retained all fire residues on the bags to avoid nutrient loss resulting from fire (see Lavorel \u0026amp; Garnier 2002), approaching the actual field conditions.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Traits immediately after fire\u003c/h2\u003e \u003cp\u003eFirst, after applying the burning treatment, the regrowth potential was evaluated by regrowth speed, where we considered the initial time (first day) the day after the fire and the final time (last day) when the first tiller emerged (green part); evaluation of the regrowth time lasted ca. 30 days. We considered tillering (architecture) also a regrowth attribute (P\u0026eacute;rez-Harguindeguy et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). It is noteworthy that we did not consider the occurrence of defoliation without burning, to have a control experiment.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eList of attributes measured in adult plants of \u003cem\u003eSetaria parviflora\u003c/em\u003e in both treatments: post-fire and without fire (control).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAttributes\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eObjectives\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eData collection and evaluation method\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003ePost-fire\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eReferences\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRoot length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess survival and fitness potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePachymeter (mm).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLarson et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2015\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeaves number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess fitness.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eContinuous count\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBotha et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess survival and fitness potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePachymeter (mm).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eLarson et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2015\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCulm diameter\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess survival and fitness potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePachymeter (mm), from 1 cm above the ground.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eWigley \u003cem\u003eet al\u003c/em\u003e., 2021\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSide branches\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEvaluate architectural changes due to fire exposure.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eContinuous count.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP\u0026eacute;rez-Harguindeguy et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Botha et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResprouting ratio speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess resprout potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eContinuous Count per day.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eP\u0026eacute;rez-Harguindeguy et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2013\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurvival rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess survival rate.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePercentage (%).\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBotha et al., \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFlowering ratio speed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess reproductive potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eContinuous count per day.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eWigley et al., \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2020\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeeds number\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAssess reproductive potential.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eContinuous count.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eYes\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eBenvenuti, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2007\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026gt;\u0026gt;\u0026gt;Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Traits in the reproductive stage\u003c/h2\u003e \u003cp\u003eWe monitored seedling development in regrown plants until they reached the reproduction stage (spikelet emission) and evaluated the functional traits in all plants from both the post-fire and control (no fire) treatments (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). We assessed the reproductive attribute \"reproduction speed\" by conducting daily counts of all surviving plants in the post-fire group and those in the control group. For the post-fire group, the initial time point was the start of regrowth (first tiller emergence), and the final time point was spikelet emission. In the control group, the initial time point was the first day of germination (coleoptile emergence), and the final time point was also spikelet emission. For all plants that reproduced, we recorded the number of seeds produced per spikelet.\u003c/p\u003e \u003cp\u003eTo evaluate fitness in terms of reproductive aspects, we measured growth traits at the end of the experiment (once reproduction occurred). These traits included total plant height, culm diameter and height, number of leaves, and root length (\u003cem\u003ee.g.\u003c/em\u003e, Botha et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Larson et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Plants in the control group remained in the greenhouse throughout the entire experimental period.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.5 Data analyses\u003c/h2\u003e \u003cp\u003eTo verify if fire affects the reproduction speed, we made analyses of survival curves through the non-parametric estimator Kaplan-Meier (Kaplan \u0026amp; Meier \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1958\u003c/span\u003e), with the survfit function of the package survival (Therneau \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). The survival curves of both groups (post-fire \u003cem\u003evs.\u003c/em\u003e control) were compared through the log-rank test (or Mantel-Haenszel test) (Harrington \u0026amp; Fleming \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e1982\u003c/span\u003e), applying the function survdiff. The log-rank test calculates a Chi-Square (χ\u003csup\u003e2\u003c/sup\u003e) value for all events in each group and sums the results. The sum of these results for each group are utilized to generate a χ\u003csup\u003e2\u003c/sup\u003e to compare the full curves of each group. The curves also can visually be compared by plotting confidence intervals. Non-overlapping confidence intervals indicate significant difference between curves. The survival graph was presented with inverted curves for better observation reproduction ratio speed.\u003c/p\u003e \u003cp\u003eWe used Shapiro-Wilk test to test the normality of each treat and Levene test to variance homogeneity. To assess the responses of the traits to fire, because all traits have a normal or approximately normal distribution, we utilized Linear mixed models (LMM). Because of heteroscedasticity, we specified the within-groups variance structure in the model. We set the four lots per treatment as a random effect for the model intercept. The model assumptions were acceded by diagnostic plots (fitted versus residuals). Besides, to evaluate the effect of fire on the variability of traits, we calculated the coefficient of variation (CV) of traits in each treatment. All statistical analyses were performed using the program R packages (R Core Team \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e"},{"header":"3 RESULTS","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Seedling survival rate and regrowth traits\u003c/h2\u003e \u003cp\u003eThe seedling survival rate was 77% in the post-fire group. The regrowth speed was 6.4 seedlings/day, recorded between the 3r\u003csup\u003ed\u003c/sup\u003e and 14th day (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). Despite the whole aerial part having been burned, regrowth started from the return of the main culm (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eB) and the emergence of tillers (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). We did not find the tillering in the control group.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e\u0026gt;\u0026gt;\u0026gt; Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e \u003cp\u003eThe culm length of the control was twice longer (mean\u0026thinsp;=\u0026thinsp;333.83\u0026thinsp;\u0026plusmn;\u0026thinsp;56 mm) that of the post-fire (176.16\u0026thinsp;\u0026plusmn;\u0026thinsp;18.69 mm) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003eA samples). In the post-fire group, seedlings invested more in the culm diameter (1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22 mm) and root length (163.19\u0026thinsp;\u0026plusmn;\u0026thinsp;10.24 mm) than in the control (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003eB-C). In contrast, full plant height had a higher mean in the control (482.78\u0026thinsp;\u0026plusmn;\u0026thinsp;61.55 mm) due to culm length (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003eD). The leaf number per branch was higher in the control than in post-fire treatment (Table S1; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003eE). From the coefficient of variation, we also observed that fire determines a homogeneous response (meaning lower variation) of the attribute\u0026rsquo;s culm length, root length, total height, and seed number (Figure S2). In the traits of culm diameter and leaf number, the coefficient of variance was lower in the control (Figure S2).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e\u0026gt;\u0026gt;\u0026gt; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Reproductive traits\u003c/h2\u003e \u003cp\u003eAll plants produced seeds in both treatments. The reproduction ratio in the post-fire group was higher between the 6th and 16th day. Based on the difference between the survival curves, reproduction was significantly different between treatments (χ\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;164; p\u0026thinsp;\u0026lt;\u0026thinsp;0.001; Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003e). We observed that with fire, most plants (44) reproduced themselves within a short period homogeneously between 7th and 10th day, while in the control, reproduction was relatively heterogeneous between the 10th and 30th day, with peaks on days 22 and 23 (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). However, the number of seeds per spikelet/plant was drastically reduced in the post-fire (ca. 16) compared with the control (ca. 60) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e2\u003c/span\u003eF).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLog-Rank Mantel-Haenszel test for Kaplan-Meier estimates between control and post-fire treatments.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eO\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e(O-E) ^2/E\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e(O-E) ^2/V\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eControl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e151.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e17.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e164\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePost-fire\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e144\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e25.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e104.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e164\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eN\u0026thinsp;=\u0026thinsp;total number of seedlings per treatment, O\u0026thinsp;=\u0026thinsp;Observed, E\u0026thinsp;=\u0026thinsp;expected, and V\u0026thinsp;=\u0026thinsp;variance.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eSupplementary table 1. Mean and standard deviation (Sd) of \u003cem\u003eSetaria parviflora\u003c/em\u003e attributes per treatment (control - C and post-fire - F).\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e\u0026gt;\u0026gt;\u0026gt; Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u003c/p\u003e \u003cp\u003e\u0026gt;\u0026gt;\u0026gt; Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003c/p\u003e \u003c/div\u003e"},{"header":"4 DISCUSSION","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Seedling survival rate\u003c/h2\u003e \u003cp\u003eThe survival rate of \u003cem\u003eSetaria parviflora\u003c/em\u003e seedlings after fire was remarkably high, especially considering that small plants, being close to the ground, are typically more vulnerable to damage caused by high temperatures. This pattern reflects significant adaptations of grasses in fire-prone ecosystems. For instance, underground structures such as rhizomes and stolons are critical for post-fire survival and recovery after intense grazing, as observed in tropical grasses (Gittins et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eComparatively, grasses from other flammable ecosystems, such as \u003cem\u003eCenchrus ciliaris\u003c/em\u003e in African savannas, exhibit similar survival strategies, relying on underground storage structures and rapid vegetative regeneration (Miller et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Conversely, herbaceous plants in temperate grasslands often depend on heat-resistant seeds to persist under intense fire regimes (Larson \u0026amp; Funk \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). This diversity of strategies highlights how fire adaptations vary among species and habitats, shaping the composition and resilience of plant communities.\u003c/p\u003e \u003cp\u003eFire intensity and frequency also play critical roles. High-intensity fires can elevate soil temperatures to levels that compromise underground structures, even in grasses with deep rhizomes (Ramsay \u0026amp; Oxley \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e1996\u003c/span\u003e). Studies on Andropogon gerardii and other prairie grasses have shown that less frequent fires allow the recovery of underground reserves, whereas recurrent fires can deplete plants' regenerative capacity (Kimball et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Thus, although S. parviflora demonstrated high survival rates in the present study, its response likely varies significantly depending on fire intensity and frequency.\u003c/p\u003e \u003cp\u003eFurthermore, the plant\u0026rsquo;s life stage directly influences its ability to withstand fire. Young seedlings and plants in early developmental stages are generally more vulnerable, while mature plants with more developed underground systems exhibit greater resilience (Archibald et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Larson et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In the case of S. parviflora, the initiation of rhizome development during the seedling stage may have contributed to the observed 77% survival rate, underscoring the importance of this trait for the species' persistence in environments subject to extreme disturbances.\u003c/p\u003e \u003cp\u003eUnderstanding how different fire intensities affect seedling survival and the development of grasses such as S. parviflora is essential for comprehending plant regeneration dynamics in flammable ecosystems. This knowledge not only aids in predicting changes in vegetation composition under altered fire regimes but also provides critical insights for management and conservation strategies, particularly in tropical wetlands like the Pantanal.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Regrowth traits\u003c/h2\u003e \u003cp\u003eThe regrowth speed observed from the third day after the fire reinforces the idea that fire acts as a key driver in the dynamics of the herbaceous layer, as previously suggested in other studies (Parrini \u0026amp; Owen-Smith \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). This response indicates that traits promoting fire resilience, such as regenerative capacity, are already present during the early stages of development. Plants adapted to fire-prone environments often possess underground structures, such as rhizomes and storage organs, which play a critical role in vegetation regeneration and resilience (Fidelis et al. 2014; Le Stradic et al. 2020). These attributes result from selective pressures in environments with recurring fires, leading some species to evolve as \"resprouters\" (Lamont \u0026amp; Downes \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Pausas \u0026amp; Keeley \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Pausas et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). However, further studies are needed to understand the long-term impacts of fire management on seedlings.\u003c/p\u003e \u003cp\u003eIn our study, regeneration was initiated by both the main culm and tillers, with fire clearly inducing changes in plant architecture. While the control group showed no evidence of tillering, fire-exposed plants exhibited uniform post-fire tillering. This response suggests that fire not only triggers regeneration but also directly influences plant morphology. Architectural changes, such as an increase in extravaginal tillering, can lead to more decumbent lateral colonization strategies, reducing plant height (Briske \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1991\u003c/span\u003e). This reduction may have important implications, such as decreased attractiveness to herbivory in areas with shorter grasses (Pfeiffer \u0026amp; Hartnett \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e1995\u003c/span\u003e). Moreover, increased tillering can result in a higher number of inflorescences, potentially altering population dynamics and plant community composition in savanna ecosystems.\u003c/p\u003e \u003cp\u003eComparisons with other species in the same ecosystem provide further insights into differential fire responses. For example, grasses such as \u003cem\u003eAndropogon bicornis\u003c/em\u003e, also common in savanna and wetland areas, show rapid post-fire regeneration but tend to maintain greater height (Damasceno-J\u0026uacute;nior et al. 2022), making them more attractive to herbivory (Hoffmann \u0026amp; Moreira 2002). In contrast, invasive grass species like \u003cem\u003eUrochloa brizantha\u003c/em\u003e rely more heavily on seed-based regeneration and tend to increase in dominance following frequent fires, potentially excluding native species (Vil\u0026agrave; et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). These comparisons highlight how \u003cem\u003eS. parviflora\u003c/em\u003e combines post-fire tillering and the development of longer roots as strategies to persist in disturbance-prone environments.\u003c/p\u003e \u003cp\u003eAdditionally, changes in plant architecture can influence interspecific competition and population regeneration processes. The reduced height of fire-exposed plants may favor taller competing species, altering plant community structure (Archibald \u0026amp; Bond \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). However, the increased root length observed in fire-exposed plants offers competitive advantages in resource uptake, especially in stressed environments. Longer roots are often associated with greater capacity for water and nutrient extraction, traits essential in wetland ecosystems subjected to fire and drought cycles (Le Stradic et al. 2020).\u003c/p\u003e \u003cp\u003eThe structural changes observed, such as reduced culm length in burned plants and increased root length, have direct implications for vegetation resilience and community composition. In areas prone to grass invasions, the relationship between abundance and fire regimes can amplify the risk of recurring fires, favoring invasive species at the expense of native ones (Vil\u0026agrave; et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). Understanding how fire alters the architecture of species like \u003cem\u003eS. parviflora\u003c/em\u003e is crucial for predicting dominance patterns and designing effective management and conservation strategies.\u003c/p\u003e \u003cp\u003eFinally, even at early stages such as seedlings, \u003cem\u003eS. parviflora\u003c/em\u003e exhibited adaptive traits that ensured a relatively high survival rate. The development of longer roots and the presence of tillers contributed to its resilience and post-fire regrowth. These responses underscore the importance of studies that consider different fire intensities and frequencies, as well as their impacts on coexisting species, to fully comprehend the dynamics of regeneration in ecosystems subject to extreme disturbances, such as the Pantanal.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e4.3 Reproductive traits\u003c/h2\u003e \u003cp\u003eAll regrowth individuals produced reproductive structures, and our study found that fire accelerated the rate of reproduction. Previous field studies, such as those on certain sedges (\u003cem\u003eBulbostylis paradoxa\u003c/em\u003e, \u003cem\u003eRhynchospora confusa\u003c/em\u003e, and \u003cem\u003eR. terminalis\u003c/em\u003e), have shown that flowering can occur within 24 hours after fire (Fidelis et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Pilon et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Fast reproduction is a strategy to rapidly disperse a high number of seeds within a short recruitment window (Zirondi et al. \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). However, our study indicated that although fire increased the reproduction speed, it significantly reduced the number of seeds produced per individual. This reduction can be attributed to the fact that plants, particularly in early developmental stages, prioritize regrowth and establishment over high resource allocation to reproduction. Thus, the observed fast reproduction may not necessarily correlate with effective seed production and dispersal, raising questions about long-term population sustainability.\u003c/p\u003e \u003cp\u003eReproductive dynamics play a crucial role in genetic diversity and population success. In species such as \u003cem\u003eS. parviflora\u003c/em\u003e, fast reproductive events after fire may promote cross-pollination among nearby populations due to flowering synchronization, enhancing genetic variability (Wright et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). On the other hand, reduced seed production per individual may limit long-distance dispersal, restricting the colonization of new habitats and favoring genetically more homogeneous populations. This limitation may be partially offset by the increase in post-fire tillering, which can lead to a greater number of spikelets per individual over time (Keeley et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Higher spikelet production may contribute to the maintenance of local populations, although its impact on the structure of plant communities still requires investigation.\u003c/p\u003e \u003cp\u003eHistorically, open savanna ecosystems often exhibit more flowering in burned areas compared to unburned areas (Fidelis \u0026amp; Blanco \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). This difference is influenced by the plants' ability to rapidly allocate resources to reproduction after the removal of aerial biomass, when competition for light is reduced and the availability of soil nutrients increases (Keeley et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Moreover, the fire regime plays a critical role in shaping reproductive strategies (Fidelis et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Factors such as fire frequency, intensity, and seasonality can influence the ability of plants to combine vegetative propagation strategies with seed production and dispersal (Lamont et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Frequent fire regimes may favor species with high resilience and rapid reproductive strategies but may disadvantage species requiring longer intervals between disturbances to accumulate energy reserves and produce a larger seed yield.\u003c/p\u003e \u003cp\u003eEnvironmental conditions, such as water availability, nutrients, and light intensity, also directly influence post-fire reproductive success (Pyke \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). In wetlands areas like the Pantanal, seasonal changes and drought cycles may interact with fire regimes, altering the conditions for germination and establishment of new plants (Soares et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). These interactions are critical in determining the composition of plant communities and may favor species with a greater capacity to adapt to multiple disturbances.\u003c/p\u003e \u003cp\u003eOur findings demonstrate that this species exhibits resilience and versatility in response to disturbances such as fire. Despite its high seed dispersal capacity and role in pasture regeneration through seed banks (Bao et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), the species also shows significant potential for regrowth, even when fire occurs at an early developmental stage. However, further studies are needed to understand how reproductive strategies influence population dynamics and genetic diversity in the long term, especially in the context of climate change, which may intensify fire regimes and alter the environmental conditions these species inhabit.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e4.4 Structural Implications in Grasslands\u003c/h2\u003e \u003cp\u003eRegarding the main questions driving this study, the fire occurrence during the seedling stage significantly impacts plant development up to reproduction. The plant tends to allocate more resources to traits associated with regrowth and persistence, such as root length and tiller production. Despite exhibiting a higher reproduction rate, \u003cem\u003eS. parviflora\u003c/em\u003e showed a reduction in seed production compared to the control group. This pattern suggests that, at early developmental stages, the plant prioritizes strategies that enhance its resilience and immediate survival over a high allocation of resources to reproduction. However, our study did not evaluate subsequent reproductive phases, such as the number of spikelets per culm, nor did it test seed viability. Therefore, traits related to regrowth provided a more comprehensive understanding of ecological colonization strategies than purely reproductive characteristics.\u003c/p\u003e \u003cp\u003ePrevious studies indicate that changes in fire regimes can drastically affect colonization strategies and the maintenance of grasses in wetland ecosystems. Our findings suggest that even after a single fire event, the disturbance regime can alter plant architecture, promoting increased tillering and resulting in shorter, more branched individuals. These traits may enhance individual persistence through the development of underground structures, such as rhizomes, while potentially reducing population regeneration via the seed bank. This reduction may limit the species' expansion in the Pantanal but could also contribute to the stability of local populations in contexts of high resource competition.\u003c/p\u003e \u003cp\u003eContextualizing these results, it is possible to extrapolate that the versatility of \u003cem\u003eS. parviflora\u003c/em\u003e in responding to fire and other disturbances positions it as a species well-adapted to a wide range of ecological scenarios. This adaptability has implications not only for the structure and composition of local plant communities but also for management strategies in wetland ecosystems vulnerable to invasions and alterations in disturbance regimes. Future studies should further investigate seed viability, the impacts of long-term fire regimes, and competitive interactions in natural communities to better understand the ecological role and potential threats associated with \u003cem\u003eS. parviflora\u003c/em\u003e and other grasses.\u003c/p\u003e \u003c/div\u003e"},{"header":"5 CONCLUSIONS","content":"\u003cp\u003eRegrowth traits reflect the primary strategy of the species maintenance, and, despite fast reproduction, seed production was low. Our findings indicate that seedlings of the model species (\u003cem\u003eS. parviflora\u003c/em\u003e) are capable of withstanding fire exposure, leading to changes in plant produced tillers and increased regeneration potential through rhizomes. These adaptations, although effective for individual persistence, may lead to a reduction in the species' seed bank, which, in turn, could negatively affect long-term population regeneration. Based on these findings, it is essential to consider the potential ecological impacts and implications for managing grasslands subjected to frequent fire regimes. Management strategies could focus on balancing the need to maintain the seed bank with preserving species resilience to disturbances, ensuring both long-term regeneration and the stability of the plant community.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAUTHORS CONTRIBUTION\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization \u0026ndash; FB; Funding acquisition \u0026ndash; GADJ; Investigation \u0026ndash; FB, GADJ; Supervision \u0026ndash; GADJ; Writing \u0026ndash; Original Draft \u0026ndash; FB, EBS, AP, GADJ; Writing \u0026ndash; Review \u0026amp; Editing \u0026ndash; FB, EBS, AP, GADJ; Visualization \u0026ndash; FB, EBS, AP, GADJ.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDECLARATION OF COMPETING INTEREST\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could influence this paper.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDATA AVAILABILITY\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData will be made available on request.\u003c/p\u003e\n\u003cp\u003eThis work was supported by the PELD Program (CNPq process 445354/2020-8; FUNDECT 427/2021), Instituto de Meio Ambiente de Mato Grosso do Sul (IMASUL TF 001/2022), and MCTI - Pantanal Research Network (grant number: FINEP: 01.20.0201.00). We are also grateful for the first author postdoctoral scholarship (CNPq process 150922/2022-1) and AP researcher grant (CNPq process 309698/2021-9), and for grants of GADJ (CNPq process 312500/2022-0).\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eArchibald S, Bond WJ (2003) Growing tall vs growing wide: Tree architecture and allometry of Acacia karroo in forest, savanna, and arid environments. Oikos 102: 3-14.\u003c/li\u003e\n\u003cli\u003eArchibald S, Hempson GP, Lehmann C (2019) A unified framework for plant life history strategies shaped by fire and herbivory. New Phytol 224: 1490-1503. \u003c/li\u003e\n\u003cli\u003eBao F, Pott A, Ferreira FA, Arruda R (2014) Soil seed bank of floodable native and cultivated grassland in the Pantanal wetland: effects of flood gradient, season and species invasion. 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J Veg Sci 32: e12995.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"wetlands","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wela","sideBox":"Learn more about [Wetlands](https://www.springer.com/journal/13157)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/wela/default.aspx","title":"Wetlands","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Fire, Reproduction speed, Seedling traits, Survival strategies","lastPublishedDoi":"10.21203/rs.3.rs-5059283/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5059283/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eClimate change and land use are intensifying wildfires in the Brazilian Pantanal, altering the dynamics of natural grasslands. Grasslands subjected to burning can experience turnover in species composition depending on fire intensity and frequency. Understanding species persistence and regeneration strategies is essential for predicting when and where fire-induced changes in plant communities may occur. Our objective was to evaluate how fire affects the seedling stage and influences survival and development, and reproductive traits. We exposed seedlings of the grass \u003cem\u003eSetaria parviflora\u003c/em\u003e to fire and then assessed seedling performance (\u003cem\u003ee.g.\u003c/em\u003e, survival rate, regrowth speed) and adult plant characteristics (\u003cem\u003ee.g\u003c/em\u003e., reproduction speed, seed number per spikelet) of the surviving plants compared to those of a control group without fire exposure. We also evaluated attributes related to survival, such as culm length, leaves, architecture (tillers), and roots. The survival rate was high (77%), with regrowth speed increasing after the third day post-fire. Plants that regrew after the fire had longer roots and more tillers (\u0026plusmn;\u0026thinsp;3) compared to the control group, showing significant differences. In contrast, the control group had longer culms. Regrowth attributes reflect the primary strategy for species maintenance, and despite the faster reproduction, seed production was low. Our findings suggest that fire during the seedling stage reduces the number of seeds produced, even though it enhances reproduction speed, modifies plant architecture, and increases regeneration potential through rhizomes.\u003c/p\u003e","manuscriptTitle":"Fire-driven shifts in growth and reproduction strategies of Setaria parviflora in wetland ecosystems.","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-06 07:02:26","doi":"10.21203/rs.3.rs-5059283/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Accept","date":"2025-01-13T10:36:57+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-01-09T07:04:25+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-12-10T19:10:05+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-12-05T09:37:09+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Wetlands","date":"2024-12-05T09:29:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Wetlands","date":"2024-12-04T07:19:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"wetlands","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wela","sideBox":"Learn more about [Wetlands](https://www.springer.com/journal/13157)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/wela/default.aspx","title":"Wetlands","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"d5c91edd-6c2c-41b9-b436-35f12255a599","owner":[],"postedDate":"December 6th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-01-27T16:02:36+00:00","versionOfRecord":{"articleIdentity":"rs-5059283","link":"https://doi.org/10.1007/s13157-025-01903-1","journal":{"identity":"wetlands","isVorOnly":false,"title":"Wetlands"},"publishedOn":"2025-01-22 15:57:47","publishedOnDateReadable":"January 22nd, 2025"},"versionCreatedAt":"2024-12-06 07:02:26","video":"","vorDoi":"10.1007/s13157-025-01903-1","vorDoiUrl":"https://doi.org/10.1007/s13157-025-01903-1","workflowStages":[]},"version":"v1","identity":"rs-5059283","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5059283","identity":"rs-5059283","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}