Population dynamics and conservation strategies for Echinocactus platyacanthus: A data- driven approach to protecting an endemic species

Population dynamics and conservation strategies for Echinocactus platyacanthus: A data- driven approach to protecting an endemic species | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Population dynamics and conservation strategies for Echinocactus platyacanthus: A data- driven approach to protecting an endemic species Erasmo Vázquez-Díaz, Huitzimengari Campos, José Rodolfo García-Nava, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5486568/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Echinocactus platyacanthus , an endemic and threatened species in Mexico, faces population declines due to overexploitation and habitat disturbance. To inform conservation strategies, we studied the population dynamics of six populations distributed across Central Mexico using demographic data and Integral Projection Models (IPMs). Our results showed considerable variation in asymptotic growth rates (λ) across populations and years (ranging from 0.9753 to 1.0842), highlighting local differences in population performance. Elasticity analyses revealed that survival-growth kernel had the greatest contribution to population persistence (96.6–99.7%), while the fertility kernel played a minimal role (0.3–3.4%). We emphasize the need for conservation efforts to focus on protecting medium to large individuals, which contribute significantly to population growth and stability. Limited seedling recruitment suggests that measures aimed at enhancing juvenile survival and reducing predation could improve population recovery. Our findings underscore the importance of tailored local conservation strategies to safeguard this species’ long-term viability. Candy barrel cactus population dynamics integral projection model conservation strategy vital rates Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Demographic studies on endangered plants play a critical role in both population management and the development of successful conservation strategies, as such studies provide powerful insights into the factors driving population decline (Buckley and Puy 2022 ). A comprehensive understanding of population demography is essential for designing a recovery plan for any threatened species (Cogoni et al. 2019 ). Additionally, for effective recovery management, it is important to recognize population variations across the species’ range (Sulis et al. 2020 ). In particular, evaluating population trends at the local level is crucial for understanding the mechanisms influencing vital rates in different populations, especially for endemic and/or threatened plant species. Research has shown that populations of the same species, even those in close proximity, can exhibit strong local adaptations and low correlations with overall population performance (Dibner et al. 2019 ). These adaptations to local environmental conditions, especially at the edges of the species' range, are often influenced by geographic and ecological gradients (Villellas et al. 2013 ), as well as factors like ecological niche variation (Papuga et al. 2018 ) and varying levels of human-induced disturbance. Despite the successful application of demographic analysis in plant ecology and evolutionary biology (Coulson 2012 ; Dibner et al. 2019 ), its use in conservation biology remains limited, particularly in regions like Mexico (Nicolè et al. 2011 ; Ferrer-Cervantes et al. 2012 ). While considerable attention has been given to cacti in arid ecosystems (Godínez-Álvarez et al. 2003 ), Agave species in agroforestry systems (Torres et al. 2015 ), and palms in tropical forests (Hernández-Barrios et al. 2015 ), it is imperative for a megadiverse country like Mexico to increase investment in training researchers and strengthening institutions involved in ecological and conservation research. Population dynamics, which seeks to explain variations in population size and structure over time, is a key area of study in conservation biology (Caswell 2001 ; Menges 2000 ). Determining whether a population is growing or declining is central to conservation efforts (Metcalf et al. 2013 ). Over the past few decades, population ecologists have consistently advocated for a greater use of quantitative demographic analyses to guide plant population management (Crone et al. 2011 ; Menges et al. 2016 ). Recent studies indicate that conservation needs often vary at a local level, as plant species may require different conservation measures depending on the conditions at specific locations (Fenu et al. 2020 ). Therefore, local demographic trends should serve as the primary guide for planning conservation actions at the local scale (Sulis et al. 2020 ). The candy barrel cactus ( Echinocactus platyacanthus Link & Otto), endemic to Mexico, is widely used for ornamental purposes, as fodder, and for human consumption. Overexploitation of this species has resulted in its classification under special legal protection. Despite laws prohibiting the harvest of these cacti, they continue to be destroyed in situ through illegal gathering and grazing by livestock (Jiménez-Sierra and Eguiarte 2010 ). To assess the conservation requirements for this species, this study conducted demographic analyses of six populations, representing the Mexican distribution of E. platyacanthus , to determine whether similar conservation strategies are needed across different local populations in central Mexico. Materials and methods Study species Echinocactus platyacanthus is a large, barrel-shaped cactus that can grow up to 2 meters in height and 80 centimeters in diameter (Bravo-Hollis and Sanchez-Mejorada, 1991). Endemic to Mexico, it inhabits areas between 18° N and 25° N latitudes and 97° W and 102° W longitudes (Trujillo 1984 ), primarily in the states of Coahuila, Guanajuato, Hidalgo, Nuevo León, Oaxaca, Puebla, Querétaro, San Luis Potosí, Tamaulipas, and Zacatecas. The plant’s stem is green, either light or dark, and features robust ribs, with spines emerging from its areoles (Fig. 1 A). The plant’s apex is recessed, either circular or elliptical, and covered with wool (Fig. 1 B). It produces diurnal yellow flowers, about 6 cm in diameter, and its fruits are yellow, dry, woolly, and approximately 7 cm long. The black seeds are roughly 2.5 mm in length (Jiménez-Sierra and Reyes 2000 ). Growth in E. platyacanthus is monopodial, but if the apical meristem is damaged, branching can occur, resulting in stem replication. These branches can produce new reproductive structures. Overharvesting for food, ornamental use, and other purposes has placed significant pressure on natural populations (Jiménez-Sierra et al. 2007 ), prompting the species' inclusion in Mexico’s environmental protection framework (SEMARNAT 2010 ). Data collection Demographic data were collected from six permanent plots established in six distinct populations across the species' central Mexican range (Fig. 1 C, Table 1 ). Two populations were located in San Luis Potosí, at the northwestern edge of the distribution: Coyote (CT) and Cruz (CZ); two in Querétaro, representing the central distribution: Pilón (PI) and Coyoteras (CY); and two in Puebla, marking the southern range: Moctezuma (MO) and Tempesquistle (TM). Each population's permanent plot measured 100 × 100 m and was randomly positioned within the area where the plants were concentrated. Demographic censuses were conducted over two annual transitions, spanning three years (2014–2016). During each census, all plants were marked, mapped, and regularly monitored, totaling 1,105 individuals in the initial survey (Appendix A). New seedlings emerging within the plots were also counted, measured, and mapped. Biannual surveys were conducted, with the initial survey occurring in March to map and measure plant height, maximum diameter, and rib count. For multi-stemmed individuals, measurements were taken for each stem. Survival and growth were tracked annually through March–May censuses, focusing on marked individuals. Reproductive data, including flower and fruit counts, were recorded during peak reproductive periods in July–August of each year. Seed production per fruit was estimated by counting seeds from 25 randomly collected fruits per plot, and total seed output was calculated by multiplying the average number of seeds per fruit by the fruit count per plant (Appendix B). Table 1 Geographical and ecological traits of Echinocactus platyacanthus Link & Otto populations: coordinates, elevation, soil texture, density of plants, and plant height within the monitored plots. State Population (code) Coordinates Elevation (m.a.s.l. a ) Soil texture Density Ind/ha b Height (cm) San Luis Potosí Coyote (CT) 22°38´N 100°30´W 1509 Loam 158 64 ± 3 Cruz (CZ) 22°37´N 100°30´W 1515 Loam 102 57 ± 3 Querétaro Pilón (PI) 21°3´N 99°47´W 1454 Clay loam 212 44 ± 2 Coyoteras (CY) 21°1´N 99°45´W 1307 Clay loam 178 28 ± 1 Puebla Moctezuma (MO) 18°12´N 97°38´W 2017 Clay loam 236 92 ± 2 Tempesquistle (TM) 18°12´N 97°39´W 1945 Clay 219 58 ± 2 a meters above sea level; b individuals per hectare. Demographic modelling Vital rate models were constructed to evaluate the influence of plant size ( z ) on survival, growth, and reproduction. A series of progressively complex generalized linear models were developed to assess survival ( s ( z )) and growth to size z' , conditional on survival ( g ( z’ , z )). These models used plant diameter size, along with a second-order polynomial of size, as predictors. Competing models were also created for reproduction probability ( p r ( z )) and fruit production ( r s ( z )) using either intercept-only or plant diameter size as fixed effects. Model selection was based on the lowest Akaike Information Criteria (AIC) value (Dauer and Jongejans 2013 ). Survival and reproduction probability models assumed binomial error distributions, while the growth model used Gaussian distributions. Additionally, the recruit size distribution was modeled using a truncated normal distribution, and recruitment probability was calculated by dividing the number of observed recruits by the total seed production. Each population was analyzed separately to capture local trends and assess demographic variability. Integral projection modelling and analysis We applied an Integral Projection Model (IPM) (Ellner et al. 2016 ) to combine the vital rate functions and estimate the population’s long-term dynamics. These models follow the general equation: $$\:n\left({z}^{{\prime\:}},t+1\right)={\int\:}_{L}^{U}K\left({z}^{{\prime\:}},z\right)n\left(z,t\right)dz$$ In this expression, n ( z′ , t + 1) represents the size distribution of the population at time t + 1, where z′ is the state variable used to characterize the population. The integral of this equation over the range of z′ gives the total population size. L and U are the lower and upper bounds of the state variable, respectively. K ( z′ , z ) is a bivariate kernel function describing transitions to state z′ , given an individual’s initial state z at time t . In this case, the state variable z refers to plant diameter. The kernel function K ( z′ , z ) is divided into two sub-kernels: one representing growth and survival ( P ) and the other representing sexual reproduction ( F ). These sub-kernels are further defined by functions that represent the vital rates, which were parameterized using the regression models described earlier. Therefore, our model contains two sub-kernels: P for survival-growth and F for reproduction. Incorporating these into the general equation, the model becomes: $$\:n\left({z}^{{\prime\:}},t+1\right)={\int\:}_{L}^{U}\left[P\left({z}^{{\prime\:}},z\right)+F\left({z}^{{\prime\:}},\:z\right)\right]n\left(z,t\right)dz$$ Since analytical solutions to these integrals are not available, we used numerical methods to solve the equation. Specifically, we applied the midpoint integration rule with 100 mesh points over the domain [L, U] to construct a 100x100 iteration matrix, K (Ellner et al. 2016 ). After implementing the IPM, we calculated the per-capita growth rate (λ), which represents the population growth over a single time step once the model reached its asymptotic behavior (Ellner et al. 2016 ). Additionally, we calculated the sensitivity and elasticity functions of λ at both the kernel and sub-kernel levels to assess the relative contributions of survival-growth transitions and reproductive transitions to the overall population growth rate. To account for uncertainty, we performed bootstrap resampling of the demographic data with replacement 1,000 times and re-estimated all vital rates using the same functional forms (Bogdan et al. 2021 ). IPMs were then constructed for each iteration, and per-capita growth rates, sensitivities, and elasticities were calculated. Thus, the λ values reported here represent the point estimates, along with 95% confidence intervals derived from the bootstrapping process. All analyses were performed using the "ipmr" package (version 0.0.4; Levin et al. 2021 ), and kernel plots were generated using the "ggplot2" package in R version 4.1.4 (R Core Team 2022 ). Results Survival and Growth The vital rates models confirmed that plant diameter was generally correlated with survival, growth, probability of flowering, and fruit number across both studied cycles (Fig. 2 ). In most cases, survival negatively correlated with plant size; however, several exceptions were noted. For example, in the Pilón (PI) and Moctezuma (MO) populations during both cycles, and in the Coyoteras (CY) population during cycle 1, deviations from this pattern were detected. For instance, the CY population in cycle 1 exhibited lower survival rates among smaller individuals but higher survival for intermediate and large plants. On the contrary, no clear correlation between survival and size was observed in the Coyote (CT), Cruz (CZ), and PI populations. In cycle 2, an exception occurred in PI, where survival initially decreased with size but later increased at larger diameters. Conversely, the MO population in cycle 2 showed a positive association between survival and size, with the highest mortality occurring among intermediate-sized plants. However, in the remaining populations, survival typically decreased with increasing size during this cycle. Growth rate consistently followed a linear trend, with smaller plants more likely to exhibit growth compared to larger individuals (Fig. 2 ). Larger plants, particularly in the MO and Tempesquistle (TM) populations, tended to cluster in certain size classes. Flowering probability strongly increased with diameter, especially when plants exceeded 35 cm in diameter. One notable exception occurred in the CT population during cycle 2, where flowering probability decreased for medium-large plants before increasing again for the largest individuals. Fruit production, similar to flowering, was highly dependent on size, with larger plants producing exponentially more fruits than smaller ones (Fig. 2 ). Population Growth Rates Population growth rates (λ) for the six studied populations were variable, with some populations showing growth or at least stability (Fig. 3 ). The confidence intervals surrounding these estimates were also variable across sites and cycles. In CZ during cycle 2, PI during cycle 1, and TM during cycle 2, λ overlapped with 1, indicating stable populations. However, the CT, CZ, and MO populations in cycle 2 exhibited λ values of 0.9815, 0.9977, and 0.9753, respectively. These results suggest that these populations would experience long-term declines under consistent environmental conditions and density-independent growth. The Integral Projection Model (IPM) kernels highlighted the significance of individuals across all size categories, as evidenced by the elevated values near the diagonal in the central region of the matrix. This pattern reflects the dominance of the survival function, which captures the stasis of individuals that persist into the following year without undergoing significant changes in size (Fig. 4 , first and second rows). Notably, in the populations PI, CY, MO, and TM, there was a minor contribution from the fertility kernel, observable in the bottom-right portion of the matrix (Fig. 4 , first and second rows). This contribution peaked in plants with diameters exceeding 60 cm, indicating that individuals of this size class played the most substantial role in reproduction. Moreover, the lack of representation in the bottom-left region of the matrix, which corresponds to new seedlings entering the smallest size class, suggests that seedling emergence was limited. The low survival rate of seedlings further confirms the high mortality of smaller individuals and the overall low seedling recruitment. The elasticity values were predominantly elevated along the diagonal, reflecting the survival of individuals across various size classes in a state of stasis. However, notable exceptions occurred in the CT, CZ, and CY populations during cycle 1, and in the PI population during both cycles, where larger plants exhibited the highest elasticity values (Fig. 4 , third and fourth rows). The detailed analysis of elasticity revealed that the P component, representing survival-growth transitions, was significantly greater than the F component, which corresponds to reproduction, across all populations. This finding indicates that survival and growth were the primary drivers of the population growth rate (λ) (Table 2 ). In all instances, the F component's contribution was either minimal or completely absent (Fig. 4 ). Table 2 Population growth rate (λ), and elasticity partition ( P and F components) of the six Echinocactus platyacanthus Link & Otto populations in the two transitions (C = cycles). Population (code) λ P component F component C1 C2 C1 C2 C1 C2 Coyote (CT) 1.0191 (1.0167–1.0377) 0.9814 (0.9759–0.9905) 0.9846 0.9973 0.0153 0.0026 Cruz (CZ) 1.0276 (1.0217–1.0792) 0.9977 (0.9920–1.0494) 0.9714 0.9913 0.0285 0.0086 Pilón (PI) 1.0465 (0.9908–1.0747) 1.0539 (1.0522–1.0805) 0.9753 0.9759 0.0246 0.0240 Coyoteras (CY) 1.0842 (1.0631–1.0891) 1.0292 (1.0126–1.0353) 0.9661 0.9796 0.0338 0.0203 Moctezuma (MO) 1.0130 (1.0086–1.0350) 0.9753 (0.9749–0.9972) 0.9882 0.9979 0.0117 0.0020 Tempesquistle (TM) 1.0558 (1.0385–1.0562) 1.0027 (0.9994–1.0085) 0.9710 0.9955 0.0289 0.0044 95% confidence intervals (95% CI) are shown in brackets. Discussion The use of demographic data has been recognized as one of the most effective and cost-efficient strategies for the recovery of narrow endemic and threatened plant species, as it provides critical insights into whether populations are declining, increasing, or stable (Menges 2000 ; Cogoni et al. 2019 ; Sulis et al. 2020 ). Despite the essential role that detailed demographic studies play in assessing the conservation status of such species and in informing appropriate conservation programs, few investigations have been conducted on Echinocactus platyacanthus . The studies that do exist primarily utilize matrix models (Jiménez-Sierra et al. 2007 ). In the current study, the short-term population dynamics of E. platyacanthus were found to be in equilibrium (λ ≈ 1), although this seems inconsistent with the threats and human disturbances observed in the field (Jiménez-Sierra et al. 2007 ). The analysis demonstrated that the local trends of the four fundamental demographic functions (growth, survival, flowering probability, and fruit production) were largely size-dependent. Survival generally increased with plant size, smaller individuals were more likely to grow than larger ones, and larger plants exhibited higher fecundity (Fig. 2 ). Most populations consisted primarily of medium-sized individuals with few seedlings and exhibited high mortality among medium-sized plants. This pattern, in conjunction with the slow growth of the species (stasis), suggests a low capacity for colonization but high local persistence, which is similar to other cacti species (Godínez-Álvarez et al. 2003 ; Arroyo-Cosultchi et al. 2016 ). However, vital rates and population dynamics varied between populations and across years (Fig. 3 ). Some populations exhibited growth, some appeared to be stable, and others were in decline, reflecting variability likely driven by environmental conditions, origin zones, and stochastic factors. This pattern may result from ecological conditions typical of arid systems or animal-mediated factors, such as grazing or the direct removal of plants (Jiménez-Sierra and Eguiarte 2010 ). Echinocactus platyacanthus plays a crucial role in the xerophilous scrublands of northern and central Mexico, serving as an important resource for local communities. Despite its illegal extraction, the species continues to be harvested, particularly for the production of "acitrón," a traditional Mexican candy sold widely across the country (Jiménez-Sierra and Eguiarte, 2010 ). Habitat alteration has led to significant challenges for the remaining populations, which generally exhibit low densities. The highest recorded density in this study was 236 individuals per hectare in the Moctezuma (MO) population (Table 1 ), a figure lower than those reported for other locations (Jiménez-Sierra et al. 2007 ; Jiménez-Sierra and Eguiarte, 2010 ). This reduction may be due to natural population declines or the effects of long-term disturbances. Human activity has also impacted the height of plants, with no individuals in the studied populations exceeding 100 cm, although the species can grow up to 200 cm (Jiménez-Sierra and Eguiarte, 2010 ). Larger plants are particularly targeted for collection, which explains their reduced presence. As expected, the elasticity analysis (Fig. 4 , third and fourth rows) confirmed that the P component (survival-growth transitions) was consistently higher than the F component (reproduction) in all populations (Table 2 ), indicating that the survival-growth transitions were the primary drivers of population growth (λ), with larger plants contributing most to reproduction. The absence of evidence in the bottom-left region of the IPM kernels (Fig. 4 ), which corresponds to seedlings entering the smallest size class (0–3 cm), suggests that only a limited number of seedlings were recruited and a small percentage survived to the following year, consistent with previous findings in other cacti species (Godínez-Álvarez et al. 2003 ; Jiménez-Sierra et al. 2007 ; Arroyo-Cosultchi et al. 2016 ). The sensitivity analysis further indicated that the rapid growth of individuals already of moderate size would have the most substantial impact on λ (Appendix C). This greater sensitivity of population growth to changes in adult survival and growth, as opposed to reproduction, is characteristic of many long-lived species (Silvertown et al. 1993 ). Indeed, in long-lived, iteroparous species, fecundity is generally less influential for population growth compared to survival (Silvertown et al. 1993 ; Franco and Silvertown 2004 ). Across the plant kingdom, the elasticity of λ to survival is known to increase with species longevity (Salguero-Gómez et al. 2016 ; Bogdan et al. 2021 ), underscoring the importance of maintaining healthy adult populations for long-term persistence in perennial plants. Moreover, in semiarid and arid ecosystems characterized by high environmental variability, perennial shrubs rely heavily on longevity for survival. The significant energy investment required for seedling establishment tends to divert resources toward stress tolerance mechanisms, enhancing survival but reducing reproductive output (Aragón et al. 2009 ). Therefore, the variability in population dynamics observed among the E. platyacanthus populations is likely attributable to microclimatic and ecological conditions that influence the relationship between plant size and vital rates. The disparity between the high number of seeds produced per fruit (Ruiz-Pérez et al. 2021 ) and the low seedling recruitment rates has been previously documented (Jiménez-Sierra et al. 2007 ), and seed limitation has been recognized as a significant bottleneck for many plant species (Turnbull et al. 2000 ; Clark et al. 2007 ). In studies of columnar cacti, the absence of seedlings is often inferred indirectly through germination or field experiments (Godínez-Alvarez and Valiente-Banuet, 2004 ; Esparza-Olguín et al. 2005 ; Rojas-Sandoval and Melendez-Ackerman, 2013 ). For many cactus species, recruitment occurs only in favorable years (Mandujano et al. 2001 ; Godínez-Alvarez et al. 2003), and the lack of recruitment during unfavorable years contributes to a pattern of population stasis. Indeed, recruitment in the studied populations ranged from 4 to 16 seedlings per hectare (Appendix B). Seedling survival is particularly low during the first year, with high mortality representing a significant bottleneck in the life cycle (Clark et al. 2007 ). The low establishment rates observed in cacti populations can be attributed to a combination of abiotic, biotic, and intrinsic factors affecting various life stages, leading to reduced numbers of seedlings and juveniles. For example, E. platyacanthus populations exhibited a frequency of 2 to 39 individuals per hectare in the smallest size class (diameter < 10 cm) (Appendix D). Conclusion Demographic studies of endangered plant species serve as a crucial foundation for developing effective conservation strategies and guiding population management efforts (Godefroid et al. 2011 ; Menges et al. 2016 ; Sulis et al. 2018 ). The findings from this study provide significant insights that can inform conservation actions for Echinocactus platyacanthus , a species of particular interest in Mexico. Our results emphasize that the survival of medium to large reproductive individuals is a critical factor for ensuring the long-term viability of E. platyacanthus populations. Consequently, conservation measures should prioritize the protection and enhancement of these medium to large plants, particularly in regions where human disturbances, such as grazing and illegal harvesting, are prevalent. As shown by prior research, the extreme environmental conditions typical of arid and semi-arid regions (e.g., drought, low nutrient availability, and high temperatures) significantly affect the persistence of plant populations in these habitats (Aragón-Gastélum et al. 2017 ; Antonini et al. 2020 ). In addition to these environmental stresses, external threats like livestock grazing and the removal of individuals for human consumption further exacerbate population declines by reducing the number of reproductive individuals and limiting the species' reproductive capacity (Jiménez-Sierra and Eguiarte, 2010 ). This is consistent with the study's findings on the extremely low rate of seedling recruitment, which represents a bottleneck for population growth. To address this seedling limitation and improve juvenile survival, conservation efforts should focus on reducing seedling predation and enhancing seed-to-seedling transitions through methods such as hand sowing. Reintroducing seedlings into the population may also be an effective management strategy, as has been demonstrated in other cactus species (Esparza-Olguín et al. 2002 ; Flores-Martínez et al. 2010 ). Finally, long-term monitoring of all populations is essential, though it poses challenges. Nevertheless, continuous monitoring is critical for assessing the conservation status of E. platyacanthus and implementing effective conservation strategies at the local level. Declarations Competing Interests: The authors have no relevant financial or non-financial interests to disclose. Funding: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Author Contribution Erasmo Vázquez-Díaz and José Rodolfo García-Nava designed the study. Erasmo Vázquez-Díaz collected the data. Huitzimengari Campos did the integral projection models, statistical data analysis and prepared the manuscript with contributions from all authors. Cecilia Beatriz Peña-Valdivia, Ebandro Uscanga-Mortera and Ma. Carmen Ybarra-Moncada provided guidance throughout the study and prepared for the revision. All authors read, reviewed, and approved the final version of the paper. Acknowledgement Erasmo Vázquez-Díaz was a doctoral student from Programa de Doctorado en Botánica, Colegio de Postgraduados and received fellowship from CONAHCYT. Data Availability Data and code are provided via the following link: https://github.com/Huitzimengari/ipmrDataAnalysis/tree/main/analysisR References Antonini Y, Dirzo R, de Quitete-Portela R C (2020) Are protected populations of two globular cactus species facing a demographic explosion or just a bonanza. year? J Arid Environ 179:104192. https://doi.org/10.1016/j.jaridenv.2020.104192 Aragón CF, Méndez M, Escudero A (2009) Survival costs of reproduction in a short-lived perennial plant: live hard, die young. 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Biol Conserv 144:672–682. https://doi.org/10.1016/j.biocon.2010.10.003 Godínez-Alvarez H, Valiente-Banuet A (2004) Demography of the columnar cactus Neobuxbaumia macrocephala : a comparative approach using population projection matrices. Plant Ecol 174:109–118. https://doi.org/10.1023/B:VEGE.0000046052.35390.59 Godínez-Álvarez H, Valverde T, Ortega-Baes P (2003) Demographic trends in the Cactaceae. Bot Rev The 69:173–203. https://doi.org/10.1663/0006-8101(2003 )069[0173:DTITC]2.0.CO;2 Hernández-Barrios JC, Anten NP, Martínez-Ramos M (2015) Sustainable harvesting of non-timber forest products based on ecological and economic criteria. J Appl Ecol 52:389–401. https://doi.org/10.1111/1365-2664.12384 Jiménez-Sierra CL, Reyes J (2000) Las cactáceas de Metztitlán. In: Armella MA, Yánez L, Sandoval ME (eds) Metztitlán: Lugar de la Luna y las Maravillas. SEMARNAP-UAM, México, pp 46–82 Jiménez-Sierra CL, Mandujano MC, Eguiarte LE (2007) Are populations of the candy barrel cactus ( Echinocactus platyacanthus ) in the desert of Tehuacán, México, at risk? Population projection matrix and life table response analysis. Biol Conserv 135:278–292. https://doi.org/10.1016/j.biocon.2006.10.038 Jiménez-Sierra C, Eguiarte LE (2010) Candy barrel cactus ( Echinocactus platyacanthus Link & Otto): a traditional plant resource in Mexico subject to uncontrolled extraction and browsing. Econ Bot 64:99–108. https://doi.org/10.1007/s12231-010-9119-y Levin SC, Childs DZ, Compagnoni A, Evers S, Knight TM, Salguero-Gómez R (2021) ipmr: Flexible implementation of integral projection models in R. Methods Ecol Evol 12:1826–1834. https://doi.org/10.1111/2041-210X.13683 Mandujano MC, Montana C, Franco M, Golubov J, Flores-Martínez A (2001) Integration of demographic annual variability in a clonal desert cactus. Ecology 82:344–359. https://doi.org/10.1890/0012-9658(2001)082 [0344:IODAVI]2.0.CO;2 Menges ES, Pace-Aldana B, Haller SJ, Smith SA (2016) Ecology and conservation of the endangered legume Crotalaria avonensis in Florida scrub. Southeast Nat 15:549–574. https://doi.org/10.1656/058.015.0318 Menges E (2000) Population viability analysis in plants: challenges and opportunities. Trends Ecol Evol 15:51–56. https://doi.org/10.1016/S0169-5347(99)01763-2 Metcalf CJE, McMahon SM, Salguero-Gómez R, Jongejans E (2013) IPMpack: an R package for integral projection models. Methods Ecol Evol 4:195–200. https://doi.org/10.1111/2041-210x.12001 Nicolè F, Dahlgren JP, Vival A, Till-Bottraud I, Ehrlén J (2011) Interdependent effects of habitat quality and climate on population growth of an endangered plant. J Ecol 99:1211–1218. https://doi.org/10.1111/j.1365-2745.2011.01852.x Papuga G, Gauthier P, Pons V, Farris E, Thompson JD (2018) Ecological niche differentiation in peripheral populations: a comparative analysis of eleven Mediterranean plant species. Ecography 41:1650–1664. https://doi.org/10.1111/ecog.03331 R Core Team (2022) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/ Rojas-Sandoval J, Melendez-Ackerman E (2013) Population dynamics of a threatened cactus species: general assessment and effects of matrix dimensionality. Popul Ecol 55:479–491. https://doi.org/10.1007/s10144-013-0378-1 Ruiz-Pérez A, Vázquez-Díaz E, Ybarra-Moncada MC, García-Nava JR (2021) Calidad de semilla y sobrevivencia de plántulas de Echinocactus platyacanthus de tres regiones de México. Rev Fitotec 44:33–40 Salguero-Gómez R, Jones OR, Jongejans E, Blomberg SP, Hodgson DJ, Mbeau-Ache C, Zuidema PA, de Kroon H, Buckley YM (2016) Fast–slow continuum and reproductive strategies structure plant life-history variation worldwide. Proc Natl Acad Sci USA 113:230–235. https://doi.org/10.1073/pnas.1506215112 SEMARNAT (2010) Norma Oficial Mexicana NOM-059-ECOL-2010. Protección Ambiental-Especies Nativas de Mexico de Flora y Fauna Silvestres. Categorías de Riesgo y Especificaciones para su Inclusión, Exclusión o Cambio. Lista de Especies en Riesgo. Secretaría de Medio Ambiente y Recursos Naturales, Diario Oficial de la Federación, México, D.F Silvertown J, Franco M, Pisanty I, Mendoza A (1993) Comparative plant demography: relative importance of lifecycle components to the finite rate of increase in woody and herbaceous perennials. J Ecol 81:465–476. https://doi.org/10.2307/2261525 Sulis E, Bacchetta G, Cogoni D, Fenu G (2020) From global to local scale: where is the best for conservation purpose? Biodivers Conserv 30:183–200. https://doi.org/10.1007/s10531-020-02085-4 Sulis E, Bacchetta G, Cogoni D, Fenu G (2018) Short-term population dynamics of Helianthemum caput-felis , a perennial Mediterranean coastal plant: a key element for an effective conservation programme. Syst Biodivers 16:774–783. https://doi.org/10.1080/14772000.2018.1492469 Sulis E, Bacchetta G, Cogoni D, Fenu G (2017) Reproductive performance of Helianthemum caput-felis along its fragmented distribution in the Mediterranean coasts. Flora 234:24–33. https://doi.org/10.1016/j.flora.2017.06.013 Torres I, Casas A, Vega E, Martínez-Ramos M, Delgado-Lemus A (2015) Population dynamics and sustainable management of mescal agaves in central Mexico: Agave potatorum in the Tehuacán-Cuicatlán Valley. Econ Bot 69:26–41. https://doi.org/10.1007/s12231-014-9295-2 Trujillo S (1984) Distribución geográfica y ecológica de Echinocactus platyacanthus : un ejemplo de distribución disyunta. Cact Sucul Mex 4:75–81 Turnbull LA, Crawley MJ, Rees M (2000) Are plant populations seed-limited? A review of seed sowing experiments. Oikos 88:225–238. https://doi.org/10.1034/j.1600-0706.2000.880201.x Villellas J, Morris WF, Garcia MB (2013) Variation in stochastic demography between and within central and peripheral regions in a widespread short-lived herb. Ecology 94:1378–1388. https://doi.org/10.1890/12-1163.1 Additional Declarations No competing interests reported. Supplementary Files Supplementary.docx Cite Share Download PDF Status: Posted Version 1 posted 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. 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Also discoverable on Platform About Our Team In Review Editorial Policies 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-5486568","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":381006762,"identity":"c8ff2ccb-d928-4083-bec8-9b87dfbba370","order_by":0,"name":"Erasmo Vázquez-Díaz","email":"","orcid":"","institution":"Colegio de Postgraduados","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Erasmo","middleName":"","lastName":"Vázquez-Díaz","suffix":""},{"id":381006763,"identity":"27b39f32-8261-4dd6-9939-3b35d830bbf6","order_by":1,"name":"Huitzimengari Campos","email":"data:image/png;base64,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","orcid":"","institution":"Benemérita Universidad Autónoma de Puebla","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Huitzimengari","middleName":"","lastName":"Campos","suffix":""},{"id":381006764,"identity":"e882a63b-1a26-4a09-a308-1fa21ccd45f6","order_by":2,"name":"José Rodolfo García-Nava","email":"","orcid":"","institution":"Colegio de Postgraduados","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"José","middleName":"Rodolfo","lastName":"García-Nava","suffix":""},{"id":381006765,"identity":"d24ab912-a07c-4858-975a-c433b00ee47a","order_by":3,"name":"Cecilia Beatriz Peña-Valdivia","email":"","orcid":"","institution":"Colegio de Postgraduados","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Cecilia","middleName":"Beatriz","lastName":"Peña-Valdivia","suffix":""},{"id":381006766,"identity":"49980837-95ac-4395-88ff-b277347a490c","order_by":4,"name":"Ebandro Uscanga-Mortera","email":"","orcid":"","institution":"Colegio de Postgraduados","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ebandro","middleName":"","lastName":"Uscanga-Mortera","suffix":""},{"id":381006767,"identity":"57bd884a-a694-486c-8c68-e1886bfb1e84","order_by":5,"name":"Ma. Carmen Ybarra-Moncada","email":"","orcid":"","institution":"Universidad Autónoma Chapingo","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Ma.","middleName":"Carmen","lastName":"Ybarra-Moncada","suffix":""}],"badges":[],"createdAt":"2024-11-20 00:38:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5486568/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5486568/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":70496275,"identity":"a197cb93-e19a-41aa-9d25-3baeee545059","added_by":"auto","created_at":"2024-12-03 19:06:05","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2448380,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e Link \u0026amp; Otto population with monopodial growth at the Coyotera site (A), close up at the apex showing flowers and fruits (B). Photos: Erasmo Vázquez-Díaz. Location of the six populations of \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e Link \u0026amp; Ottostudied in Central Mexico (C). Coyote (CT), Cruz (CZ), Pilón (PI), Coyoteras (CY), Moctezuma (MO) and Tempesquistle (TM).\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/d5340ed26633e7622467509a.png"},{"id":70495743,"identity":"51f65934-cfd2-426a-ba4a-55053657e4ab","added_by":"auto","created_at":"2024-12-03 18:50:05","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":1862657,"visible":true,"origin":"","legend":"\u003cp\u003eRelationship between plant size and survival probability (first and second row, from up to down), plant size and growth (third and four row, from up to down), plant’s flowering probability (five and six row, from up to down) and plant size and fruits production (seven and eight row, from up to down) in cycle 1 and cycle 2 respectively. Columns correspond to the six studied populations of \u003cem\u003eEchinocactus\u003c/em\u003e \u003cem\u003eplatyacanthus\u003c/em\u003e Link \u0026amp; Otto(see Table 1). Blue lines show the best-fit model prediction. The x-axis represents the plant size at time \u003cem\u003et\u003c/em\u003e; the y-axis represents the measured variable in plants at \u003cem\u003et\u003c/em\u003e + 1.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/667e22d2a14a4fb6abc0c057.png"},{"id":70496162,"identity":"d40f5ddd-b646-469b-8b95-60252f4d6ce0","added_by":"auto","created_at":"2024-12-03 18:58:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":413093,"visible":true,"origin":"","legend":"\u003cp\u003eAsymptotic population growth rates (l) for six \u003cem\u003eEchinocactus\u003c/em\u003e \u003cem\u003eplatyacanthus\u003c/em\u003e Link \u0026amp; Otto populations and two cycles. The figure shows point estimates, determined from the dominant eigenvalue of the population’s projection matrix, and 95% confidence intervals (error bars) determined from 1000 bootstraping resamples from the likelihood distributions of all underlying parameters. The line at l= 1 indicates stability.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/290375972922a7f8a09ebf9f.png"},{"id":70495741,"identity":"16f69ca3-de08-4feb-9478-f8b9f8e749eb","added_by":"auto","created_at":"2024-12-03 18:50:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1432477,"visible":true,"origin":"","legend":"\u003cp\u003eIPM kernels (first and second row, from up to down) and relationship between plant size and elasticity (third and four row, from up to down) from cycle 1 and cycle 2. Columns correspond to the six studied populations of \u003cem\u003eEchinocactus\u003c/em\u003e \u003cem\u003eplatyacanthus\u003c/em\u003e Link \u0026amp; Otto (see Table 1). The x-axis represents plant size at \u003cem\u003et\u003c/em\u003e; the y-axis represents plant size at \u003cem\u003et\u003c/em\u003e + 1.\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/86eec3ec4508aefec481742f.png"},{"id":70847525,"identity":"f953de7c-fa5e-4124-86af-911c5012160f","added_by":"auto","created_at":"2024-12-07 23:46:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5923282,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/28bd9f47-1a3a-41de-87fc-bad3de9e200a.pdf"},{"id":70495745,"identity":"51429744-6a6b-48d8-b054-7b71bb773768","added_by":"auto","created_at":"2024-12-03 18:50:05","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":466626,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementary.docx","url":"https://assets-eu.researchsquare.com/files/rs-5486568/v1/5da01bedf23534070e030788.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Population dynamics and conservation strategies for Echinocactus platyacanthus: A data- driven approach to protecting an endemic species","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDemographic studies on endangered plants play a critical role in both population management and the development of successful conservation strategies, as such studies provide powerful insights into the factors driving population decline (Buckley and Puy \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). A comprehensive understanding of population demography is essential for designing a recovery plan for any threatened species (Cogoni et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Additionally, for effective recovery management, it is important to recognize population variations across the species\u0026rsquo; range (Sulis et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In particular, evaluating population trends at the local level is crucial for understanding the mechanisms influencing vital rates in different populations, especially for endemic and/or threatened plant species. Research has shown that populations of the same species, even those in close proximity, can exhibit strong local adaptations and low correlations with overall population performance (Dibner et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). These adaptations to local environmental conditions, especially at the edges of the species' range, are often influenced by geographic and ecological gradients (Villellas et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), as well as factors like ecological niche variation (Papuga et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) and varying levels of human-induced disturbance.\u003c/p\u003e \u003cp\u003eDespite the successful application of demographic analysis in plant ecology and evolutionary biology (Coulson \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Dibner et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2019\u003c/span\u003e), its use in conservation biology remains limited, particularly in regions like Mexico (Nicol\u0026egrave; et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Ferrer-Cervantes et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). While considerable attention has been given to cacti in arid ecosystems (God\u0026iacute;nez-\u0026Aacute;lvarez et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2003\u003c/span\u003e), \u003cem\u003eAgave\u003c/em\u003e species in agroforestry systems (Torres et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), and palms in tropical forests (Hern\u0026aacute;ndez-Barrios et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2015\u003c/span\u003e), it is imperative for a megadiverse country like Mexico to increase investment in training researchers and strengthening institutions involved in ecological and conservation research.\u003c/p\u003e \u003cp\u003ePopulation dynamics, which seeks to explain variations in population size and structure over time, is a key area of study in conservation biology (Caswell \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Menges \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Determining whether a population is growing or declining is central to conservation efforts (Metcalf et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Over the past few decades, population ecologists have consistently advocated for a greater use of quantitative demographic analyses to guide plant population management (Crone et al. \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Menges et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Recent studies indicate that conservation needs often vary at a local level, as plant species may require different conservation measures depending on the conditions at specific locations (Fenu et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Therefore, local demographic trends should serve as the primary guide for planning conservation actions at the local scale (Sulis et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe candy barrel cactus (\u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e Link \u0026amp; Otto), endemic to Mexico, is widely used for ornamental purposes, as fodder, and for human consumption. Overexploitation of this species has resulted in its classification under special legal protection. Despite laws prohibiting the harvest of these cacti, they continue to be destroyed \u003cem\u003ein situ\u003c/em\u003e through illegal gathering and grazing by livestock (Jim\u0026eacute;nez-Sierra and Eguiarte \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). To assess the conservation requirements for this species, this study conducted demographic analyses of six populations, representing the Mexican distribution of \u003cem\u003eE. platyacanthus\u003c/em\u003e, to determine whether similar conservation strategies are needed across different local populations in central Mexico.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy species\u003c/h2\u003e \u003cp\u003e \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e is a large, barrel-shaped cactus that can grow up to 2 meters in height and 80 centimeters in diameter (Bravo-Hollis and Sanchez-Mejorada, 1991). Endemic to Mexico, it inhabits areas between 18\u0026deg; N and 25\u0026deg; N latitudes and 97\u0026deg; W and 102\u0026deg; W longitudes (Trujillo \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e1984\u003c/span\u003e), primarily in the states of Coahuila, Guanajuato, Hidalgo, Nuevo Le\u0026oacute;n, Oaxaca, Puebla, Quer\u0026eacute;taro, San Luis Potos\u0026iacute;, Tamaulipas, and Zacatecas. The plant\u0026rsquo;s stem is green, either light or dark, and features robust ribs, with spines emerging from its areoles (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). The plant\u0026rsquo;s apex is recessed, either circular or elliptical, and covered with wool (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). It produces diurnal yellow flowers, about 6 cm in diameter, and its fruits are yellow, dry, woolly, and approximately 7 cm long. The black seeds are roughly 2.5 mm in length (Jim\u0026eacute;nez-Sierra and Reyes \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). Growth in \u003cem\u003eE. platyacanthus\u003c/em\u003e is monopodial, but if the apical meristem is damaged, branching can occur, resulting in stem replication. These branches can produce new reproductive structures. Overharvesting for food, ornamental use, and other purposes has placed significant pressure on natural populations (Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), prompting the species' inclusion in Mexico\u0026rsquo;s environmental protection framework (SEMARNAT \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eData collection\u003c/h3\u003e\n\u003cp\u003eDemographic data were collected from six permanent plots established in six distinct populations across the species' central Mexican range (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC, Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Two populations were located in San Luis Potos\u0026iacute;, at the northwestern edge of the distribution: Coyote (CT) and Cruz (CZ); two in Quer\u0026eacute;taro, representing the central distribution: Pil\u0026oacute;n (PI) and Coyoteras (CY); and two in Puebla, marking the southern range: Moctezuma (MO) and Tempesquistle (TM). Each population's permanent plot measured 100 \u0026times; 100 m and was randomly positioned within the area where the plants were concentrated. Demographic censuses were conducted over two annual transitions, spanning three years (2014\u0026ndash;2016). During each census, all plants were marked, mapped, and regularly monitored, totaling 1,105 individuals in the initial survey (Appendix A). New seedlings emerging within the plots were also counted, measured, and mapped. Biannual surveys were conducted, with the initial survey occurring in March to map and measure plant height, maximum diameter, and rib count. For multi-stemmed individuals, measurements were taken for each stem. Survival and growth were tracked annually through March\u0026ndash;May censuses, focusing on marked individuals. Reproductive data, including flower and fruit counts, were recorded during peak reproductive periods in July\u0026ndash;August of each year. Seed production per fruit was estimated by counting seeds from 25 randomly collected fruits per plot, and total seed output was calculated by multiplying the average number of seeds per fruit by the fruit count per plant (Appendix B).\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\u003eGeographical and ecological traits of \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e Link \u0026amp; Otto populations: coordinates, elevation, soil texture, density of plants, and plant height within the monitored plots.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eState\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePopulation (code)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCoordinates\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eElevation\u003c/p\u003e \u003cp\u003e(m.a.s.l.\u003csup\u003ea\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSoil texture\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eDensity\u003c/p\u003e \u003cp\u003eInd/ha\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eHeight\u003c/p\u003e \u003cp\u003e(cm)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSan Luis Potos\u0026iacute;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCoyote\u003c/p\u003e \u003cp\u003e(CT)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22\u0026deg;38\u0026acute;N\u003c/p\u003e \u003cp\u003e100\u0026deg;30\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1509\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLoam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e158\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e64\u0026thinsp;\u0026plusmn;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCruz\u003c/p\u003e \u003cp\u003e(CZ)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22\u0026deg;37\u0026acute;N\u003c/p\u003e \u003cp\u003e100\u0026deg;30\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1515\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLoam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e102\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e57\u0026thinsp;\u0026plusmn;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuer\u0026eacute;taro\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePil\u0026oacute;n\u003c/p\u003e \u003cp\u003e(PI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u0026deg;3\u0026acute;N\u003c/p\u003e \u003cp\u003e99\u0026deg;47\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1454\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e212\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e44\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCoyoteras (CY)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u0026deg;1\u0026acute;N\u003c/p\u003e \u003cp\u003e99\u0026deg;45\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1307\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e178\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e28\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePuebla\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMoctezuma (MO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18\u0026deg;12\u0026acute;N\u003c/p\u003e \u003cp\u003e97\u0026deg;38\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClay loam\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e236\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e92\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTempesquistle (TM)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18\u0026deg;12\u0026acute;N\u003c/p\u003e \u003cp\u003e97\u0026deg;39\u0026acute;W\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1945\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eClay\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e219\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e58\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003csup\u003ea\u003c/sup\u003e meters above sea level; \u003csup\u003eb\u003c/sup\u003e individuals per hectare.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e\n\u003ch3\u003eDemographic modelling\u003c/h3\u003e\n\u003cp\u003eVital rate models were constructed to evaluate the influence of plant size (\u003cem\u003ez\u003c/em\u003e) on survival, growth, and reproduction. A series of progressively complex generalized linear models were developed to assess survival (\u003cem\u003es\u003c/em\u003e(\u003cem\u003ez\u003c/em\u003e)) and growth to size \u003cem\u003ez'\u003c/em\u003e, conditional on survival (\u003cem\u003eg\u003c/em\u003e(\u003cem\u003ez\u0026rsquo;\u003c/em\u003e, \u003cem\u003ez\u003c/em\u003e)). These models used plant diameter size, along with a second-order polynomial of size, as predictors. Competing models were also created for reproduction probability (\u003cem\u003ep\u003c/em\u003e\u003csub\u003e\u003cem\u003er\u003c/em\u003e\u003c/sub\u003e(\u003cem\u003ez\u003c/em\u003e)) and fruit production (\u003cem\u003er\u003c/em\u003e\u003csub\u003e\u003cem\u003es\u003c/em\u003e\u003c/sub\u003e(\u003cem\u003ez\u003c/em\u003e)) using either intercept-only or plant diameter size as fixed effects. Model selection was based on the lowest Akaike Information Criteria (AIC) value (Dauer and Jongejans \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Survival and reproduction probability models assumed binomial error distributions, while the growth model used Gaussian distributions. Additionally, the recruit size distribution was modeled using a truncated normal distribution, and recruitment probability was calculated by dividing the number of observed recruits by the total seed production. Each population was analyzed separately to capture local trends and assess demographic variability.\u003c/p\u003e\n\u003ch3\u003eIntegral projection modelling and analysis\u003c/h3\u003e\n\u003cp\u003eWe applied an Integral Projection Model (IPM) (Ellner et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) to combine the vital rate functions and estimate the population\u0026rsquo;s long-term dynamics. These models follow the general equation:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:n\\left({z}^{{\\prime\\:}},t+1\\right)={\\int\\:}_{L}^{U}K\\left({z}^{{\\prime\\:}},z\\right)n\\left(z,t\\right)dz$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eIn this expression, \u003cem\u003en\u003c/em\u003e(\u003cem\u003ez\u0026prime;\u003c/em\u003e, t\u0026thinsp;+\u0026thinsp;1) represents the size distribution of the population at time \u003cem\u003et\u003c/em\u003e\u0026thinsp;+\u0026thinsp;1, where z\u0026prime; is the state variable used to characterize the population. The integral of this equation over the range of \u003cem\u003ez\u0026prime;\u003c/em\u003e gives the total population size. \u003cem\u003eL\u003c/em\u003e and \u003cem\u003eU\u003c/em\u003e are the lower and upper bounds of the state variable, respectively. \u003cem\u003eK\u003c/em\u003e(\u003cem\u003ez\u0026prime;\u003c/em\u003e, \u003cem\u003ez\u003c/em\u003e) is a bivariate kernel function describing transitions to state \u003cem\u003ez\u0026prime;\u003c/em\u003e, given an individual\u0026rsquo;s initial state \u003cem\u003ez\u003c/em\u003e at time \u003cem\u003et\u003c/em\u003e. In this case, the state variable \u003cem\u003ez\u003c/em\u003e refers to plant diameter. The kernel function \u003cem\u003eK\u003c/em\u003e(\u003cem\u003ez\u0026prime;\u003c/em\u003e, \u003cem\u003ez\u003c/em\u003e) is divided into two sub-kernels: one representing growth and survival (\u003cem\u003eP\u003c/em\u003e) and the other representing sexual reproduction (\u003cem\u003eF\u003c/em\u003e). These sub-kernels are further defined by functions that represent the vital rates, which were parameterized using the regression models described earlier. Therefore, our model contains two sub-kernels: \u003cem\u003eP\u003c/em\u003e for survival-growth and \u003cem\u003eF\u003c/em\u003e for reproduction. Incorporating these into the general equation, the model becomes:\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:n\\left({z}^{{\\prime\\:}},t+1\\right)={\\int\\:}_{L}^{U}\\left[P\\left({z}^{{\\prime\\:}},z\\right)+F\\left({z}^{{\\prime\\:}},\\:z\\right)\\right]n\\left(z,t\\right)dz$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eSince analytical solutions to these integrals are not available, we used numerical methods to solve the equation. Specifically, we applied the midpoint integration rule with 100 mesh points over the domain [L, U] to construct a 100x100 iteration matrix, \u003cem\u003eK\u003c/em\u003e (Ellner et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2016\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAfter implementing the IPM, we calculated the per-capita growth rate (λ), which represents the population growth over a single time step once the model reached its asymptotic behavior (Ellner et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). Additionally, we calculated the sensitivity and elasticity functions of λ at both the kernel and sub-kernel levels to assess the relative contributions of survival-growth transitions and reproductive transitions to the overall population growth rate. To account for uncertainty, we performed bootstrap resampling of the demographic data with replacement 1,000 times and re-estimated all vital rates using the same functional forms (Bogdan et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). IPMs were then constructed for each iteration, and per-capita growth rates, sensitivities, and elasticities were calculated. Thus, the λ values reported here represent the point estimates, along with 95% confidence intervals derived from the bootstrapping process. All analyses were performed using the \"ipmr\" package (version 0.0.4; Levin et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), and kernel plots were generated using the \"ggplot2\" package in R version 4.1.4 (R Core Team \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eSurvival and Growth\u003c/h2\u003e \u003cp\u003eThe vital rates models confirmed that plant diameter was generally correlated with survival, growth, probability of flowering, and fruit number across both studied cycles (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In most cases, survival negatively correlated with plant size; however, several exceptions were noted. For example, in the Pil\u0026oacute;n (PI) and Moctezuma (MO) populations during both cycles, and in the Coyoteras (CY) population during cycle 1, deviations from this pattern were detected. For instance, the CY population in cycle 1 exhibited lower survival rates among smaller individuals but higher survival for intermediate and large plants. On the contrary, no clear correlation between survival and size was observed in the Coyote (CT), Cruz (CZ), and PI populations. In cycle 2, an exception occurred in PI, where survival initially decreased with size but later increased at larger diameters. Conversely, the MO population in cycle 2 showed a positive association between survival and size, with the highest mortality occurring among intermediate-sized plants. However, in the remaining populations, survival typically decreased with increasing size during this cycle.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eGrowth rate consistently followed a linear trend, with smaller plants more likely to exhibit growth compared to larger individuals (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Larger plants, particularly in the MO and Tempesquistle (TM) populations, tended to cluster in certain size classes. Flowering probability strongly increased with diameter, especially when plants exceeded 35 cm in diameter. One notable exception occurred in the CT population during cycle 2, where flowering probability decreased for medium-large plants before increasing again for the largest individuals. Fruit production, similar to flowering, was highly dependent on size, with larger plants producing exponentially more fruits than smaller ones (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePopulation Growth Rates\u003c/h3\u003e\n\u003cp\u003ePopulation growth rates (λ) for the six studied populations were variable, with some populations showing growth or at least stability (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The confidence intervals surrounding these estimates were also variable across sites and cycles. In CZ during cycle 2, PI during cycle 1, and TM during cycle 2, λ overlapped with 1, indicating stable populations. However, the CT, CZ, and MO populations in cycle 2 exhibited λ values of 0.9815, 0.9977, and 0.9753, respectively. These results suggest that these populations would experience long-term declines under consistent environmental conditions and density-independent growth.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Integral Projection Model (IPM) kernels highlighted the significance of individuals across all size categories, as evidenced by the elevated values near the diagonal in the central region of the matrix. This pattern reflects the dominance of the survival function, which captures the stasis of individuals that persist into the following year without undergoing significant changes in size (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, first and second rows). Notably, in the populations PI, CY, MO, and TM, there was a minor contribution from the fertility kernel, observable in the bottom-right portion of the matrix (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, first and second rows). This contribution peaked in plants with diameters exceeding 60 cm, indicating that individuals of this size class played the most substantial role in reproduction. Moreover, the lack of representation in the bottom-left region of the matrix, which corresponds to new seedlings entering the smallest size class, suggests that seedling emergence was limited. The low survival rate of seedlings further confirms the high mortality of smaller individuals and the overall low seedling recruitment.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe elasticity values were predominantly elevated along the diagonal, reflecting the survival of individuals across various size classes in a state of stasis. However, notable exceptions occurred in the CT, CZ, and CY populations during cycle 1, and in the PI population during both cycles, where larger plants exhibited the highest elasticity values (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, third and fourth rows).\u003c/p\u003e \u003cp\u003eThe detailed analysis of elasticity revealed that the \u003cem\u003eP\u003c/em\u003e component, representing survival-growth transitions, was significantly greater than the \u003cem\u003eF\u003c/em\u003e component, which corresponds to reproduction, across all populations. This finding indicates that survival and growth were the primary drivers of the population growth rate (λ) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). In all instances, the \u003cem\u003eF\u003c/em\u003e component's contribution was either minimal or completely absent (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\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\u003ePopulation growth rate (λ), and elasticity partition (\u003cem\u003eP\u003c/em\u003e and \u003cem\u003eF\u003c/em\u003e components) of the six \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e Link \u0026amp; Otto populations in the two transitions (C\u0026thinsp;=\u0026thinsp;cycles).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePopulation (code)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eλ\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e component\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003e\u003cem\u003eF\u003c/em\u003e component\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eC1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eC2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoyote (CT)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0191 (1.0167\u0026ndash;1.0377)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.9814 (0.9759\u0026ndash;0.9905)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9846\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9973\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0153\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0026\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCruz (CZ)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0276 (1.0217\u0026ndash;1.0792)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.9977\u003c/p\u003e \u003cp\u003e(0.9920\u0026ndash;1.0494)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9714\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9913\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0285\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0086\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePil\u0026oacute;n (PI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0465 (0.9908\u0026ndash;1.0747)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.0539 (1.0522\u0026ndash;1.0805)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9753\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9759\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0246\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0240\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoyoteras (CY)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0842 (1.0631\u0026ndash;1.0891)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.0292 (1.0126\u0026ndash;1.0353)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9661\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9796\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0338\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0203\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMoctezuma (MO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0130 (1.0086\u0026ndash;1.0350)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.9753 (0.9749\u0026ndash;0.9972)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9882\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9979\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0117\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0020\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTempesquistle (TM)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.0558 (1.0385\u0026ndash;1.0562)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.0027 (0.9994\u0026ndash;1.0085)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.9710\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.9955\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0289\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.0044\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e95% confidence intervals (95% CI) are shown in brackets.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe use of demographic data has been recognized as one of the most effective and cost-efficient strategies for the recovery of narrow endemic and threatened plant species, as it provides critical insights into whether populations are declining, increasing, or stable (Menges \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Cogoni et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Sulis et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Despite the essential role that detailed demographic studies play in assessing the conservation status of such species and in informing appropriate conservation programs, few investigations have been conducted on \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e. The studies that do exist primarily utilize matrix models (Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). In the current study, the short-term population dynamics of \u003cem\u003eE. platyacanthus\u003c/em\u003e were found to be in equilibrium (λ\u0026thinsp;\u0026asymp;\u0026thinsp;1), although this seems inconsistent with the threats and human disturbances observed in the field (Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe analysis demonstrated that the local trends of the four fundamental demographic functions (growth, survival, flowering probability, and fruit production) were largely size-dependent. Survival generally increased with plant size, smaller individuals were more likely to grow than larger ones, and larger plants exhibited higher fecundity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Most populations consisted primarily of medium-sized individuals with few seedlings and exhibited high mortality among medium-sized plants. This pattern, in conjunction with the slow growth of the species (stasis), suggests a low capacity for colonization but high local persistence, which is similar to other cacti species (God\u0026iacute;nez-\u0026Aacute;lvarez et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Arroyo-Cosultchi et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). However, vital rates and population dynamics varied between populations and across years (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Some populations exhibited growth, some appeared to be stable, and others were in decline, reflecting variability likely driven by environmental conditions, origin zones, and stochastic factors. This pattern may result from ecological conditions typical of arid systems or animal-mediated factors, such as grazing or the direct removal of plants (Jim\u0026eacute;nez-Sierra and Eguiarte \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e plays a crucial role in the xerophilous scrublands of northern and central Mexico, serving as an important resource for local communities. Despite its illegal extraction, the species continues to be harvested, particularly for the production of \"acitr\u0026oacute;n,\" a traditional Mexican candy sold widely across the country (Jim\u0026eacute;nez-Sierra and Eguiarte, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Habitat alteration has led to significant challenges for the remaining populations, which generally exhibit low densities. The highest recorded density in this study was 236 individuals per hectare in the Moctezuma (MO) population (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), a figure lower than those reported for other locations (Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Jim\u0026eacute;nez-Sierra and Eguiarte, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). This reduction may be due to natural population declines or the effects of long-term disturbances. Human activity has also impacted the height of plants, with no individuals in the studied populations exceeding 100 cm, although the species can grow up to 200 cm (Jim\u0026eacute;nez-Sierra and Eguiarte, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). Larger plants are particularly targeted for collection, which explains their reduced presence.\u003c/p\u003e \u003cp\u003eAs expected, the elasticity analysis (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, third and fourth rows) confirmed that the \u003cem\u003eP\u003c/em\u003e component (survival-growth transitions) was consistently higher than the \u003cem\u003eF\u003c/em\u003e component (reproduction) in all populations (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), indicating that the survival-growth transitions were the primary drivers of population growth (λ), with larger plants contributing most to reproduction. The absence of evidence in the bottom-left region of the IPM kernels (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e), which corresponds to seedlings entering the smallest size class (0\u0026ndash;3 cm), suggests that only a limited number of seedlings were recruited and a small percentage survived to the following year, consistent with previous findings in other cacti species (God\u0026iacute;nez-\u0026Aacute;lvarez et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2003\u003c/span\u003e; Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e; Arroyo-Cosultchi et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). The sensitivity analysis further indicated that the rapid growth of individuals already of moderate size would have the most substantial impact on λ (Appendix C). This greater sensitivity of population growth to changes in adult survival and growth, as opposed to reproduction, is characteristic of many long-lived species (Silvertown et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e1993\u003c/span\u003e). Indeed, in long-lived, iteroparous species, fecundity is generally less influential for population growth compared to survival (Silvertown et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e1993\u003c/span\u003e; Franco and Silvertown \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2004\u003c/span\u003e). Across the plant kingdom, the elasticity of λ to survival is known to increase with species longevity (Salguero-G\u0026oacute;mez et al. \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Bogdan et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), underscoring the importance of maintaining healthy adult populations for long-term persistence in perennial plants.\u003c/p\u003e \u003cp\u003eMoreover, in semiarid and arid ecosystems characterized by high environmental variability, perennial shrubs rely heavily on longevity for survival. The significant energy investment required for seedling establishment tends to divert resources toward stress tolerance mechanisms, enhancing survival but reducing reproductive output (Arag\u0026oacute;n et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Therefore, the variability in population dynamics observed among the \u003cem\u003eE. platyacanthus\u003c/em\u003e populations is likely attributable to microclimatic and ecological conditions that influence the relationship between plant size and vital rates.\u003c/p\u003e \u003cp\u003eThe disparity between the high number of seeds produced per fruit (Ruiz-P\u0026eacute;rez et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) and the low seedling recruitment rates has been previously documented (Jim\u0026eacute;nez-Sierra et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), and seed limitation has been recognized as a significant bottleneck for many plant species (Turnbull et al. \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2000\u003c/span\u003e; Clark et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). In studies of columnar cacti, the absence of seedlings is often inferred indirectly through germination or field experiments (God\u0026iacute;nez-Alvarez and Valiente-Banuet, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Esparza-Olgu\u0026iacute;n et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Rojas-Sandoval and Melendez-Ackerman, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). For many cactus species, recruitment occurs only in favorable years (Mandujano et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; God\u0026iacute;nez-Alvarez et al. 2003), and the lack of recruitment during unfavorable years contributes to a pattern of population stasis. Indeed, recruitment in the studied populations ranged from 4 to 16 seedlings per hectare (Appendix B). Seedling survival is particularly low during the first year, with high mortality representing a significant bottleneck in the life cycle (Clark et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2007\u003c/span\u003e). The low establishment rates observed in cacti populations can be attributed to a combination of abiotic, biotic, and intrinsic factors affecting various life stages, leading to reduced numbers of seedlings and juveniles. For example, \u003cem\u003eE. platyacanthus\u003c/em\u003e populations exhibited a frequency of 2 to 39 individuals per hectare in the smallest size class (diameter\u0026thinsp;\u0026lt;\u0026thinsp;10 cm) (Appendix D).\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eDemographic studies of endangered plant species serve as a crucial foundation for developing effective conservation strategies and guiding population management efforts (Godefroid et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2011\u003c/span\u003e; Menges et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Sulis et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). The findings from this study provide significant insights that can inform conservation actions for \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e, a species of particular interest in Mexico.\u003c/p\u003e \u003cp\u003eOur results emphasize that the survival of medium to large reproductive individuals is a critical factor for ensuring the long-term viability of \u003cem\u003eE. platyacanthus\u003c/em\u003e populations. Consequently, conservation measures should prioritize the protection and enhancement of these medium to large plants, particularly in regions where human disturbances, such as grazing and illegal harvesting, are prevalent. As shown by prior research, the extreme environmental conditions typical of arid and semi-arid regions (e.g., drought, low nutrient availability, and high temperatures) significantly affect the persistence of plant populations in these habitats (Arag\u0026oacute;n-Gast\u0026eacute;lum et al. \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Antonini et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). In addition to these environmental stresses, external threats like livestock grazing and the removal of individuals for human consumption further exacerbate population declines by reducing the number of reproductive individuals and limiting the species' reproductive capacity (Jim\u0026eacute;nez-Sierra and Eguiarte, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). This is consistent with the study's findings on the extremely low rate of seedling recruitment, which represents a bottleneck for population growth.\u003c/p\u003e \u003cp\u003eTo address this seedling limitation and improve juvenile survival, conservation efforts should focus on reducing seedling predation and enhancing seed-to-seedling transitions through methods such as hand sowing. Reintroducing seedlings into the population may also be an effective management strategy, as has been demonstrated in other cactus species (Esparza-Olgu\u0026iacute;n et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2002\u003c/span\u003e; Flores-Mart\u0026iacute;nez et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFinally, long-term monitoring of all populations is essential, though it poses challenges. Nevertheless, continuous monitoring is critical for assessing the conservation status of \u003cem\u003eE. platyacanthus\u003c/em\u003e and implementing effective conservation strategies at the local level.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting Interests:\u003c/h2\u003e \u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding:\u003c/h2\u003e \u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eErasmo V\u0026aacute;zquez-D\u0026iacute;az and Jos\u0026eacute; Rodolfo Garc\u0026iacute;a-Nava designed the study. Erasmo V\u0026aacute;zquez-D\u0026iacute;az collected the data. Huitzimengari Campos did the integral projection models, statistical data analysis and prepared the manuscript with contributions from all authors. Cecilia Beatriz Pe\u0026ntilde;a-Valdivia, Ebandro Uscanga-Mortera and Ma. Carmen Ybarra-Moncada provided guidance throughout the study and prepared for the revision. All authors read, reviewed, and approved the final version of the paper.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eErasmo V\u0026aacute;zquez-D\u0026iacute;az was a doctoral student from Programa de Doctorado en Bot\u0026aacute;nica, Colegio de Postgraduados and received fellowship from CONAHCYT.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eData and code are provided via the following link: https://github.com/Huitzimengari/ipmrDataAnalysis/tree/main/analysisR\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAntonini Y, Dirzo R, de Quitete-Portela R C (2020) Are protected populations of two globular cactus species facing a demographic explosion or just a bonanza. year? 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Ecology 94:1378\u0026ndash;1388. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1890/12-1163.1\u003c/span\u003e\u003cspan address=\"10.1890/12-1163.1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Candy barrel cactus, population dynamics, integral projection model, conservation strategy, vital rates","lastPublishedDoi":"10.21203/rs.3.rs-5486568/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5486568/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e \u003cem\u003eEchinocactus platyacanthus\u003c/em\u003e, an endemic and threatened species in Mexico, faces population declines due to overexploitation and habitat disturbance. To inform conservation strategies, we studied the population dynamics of six populations distributed across Central Mexico using demographic data and Integral Projection Models (IPMs). Our results showed considerable variation in asymptotic growth rates (λ) across populations and years (ranging from 0.9753 to 1.0842), highlighting local differences in population performance. Elasticity analyses revealed that survival-growth kernel had the greatest contribution to population persistence (96.6\u0026ndash;99.7%), while the fertility kernel played a minimal role (0.3\u0026ndash;3.4%). We emphasize the need for conservation efforts to focus on protecting medium to large individuals, which contribute significantly to population growth and stability. Limited seedling recruitment suggests that measures aimed at enhancing juvenile survival and reducing predation could improve population recovery. Our findings underscore the importance of tailored local conservation strategies to safeguard this species\u0026rsquo; long-term viability.\u003c/p\u003e","manuscriptTitle":"Population dynamics and conservation strategies for Echinocactus platyacanthus: A data- driven approach to protecting an endemic species","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-03 18:50:00","doi":"10.21203/rs.3.rs-5486568/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4bcb1f82-bd94-4136-9749-f73411a595a5","owner":[],"postedDate":"December 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-12-07T23:38:13+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-03 18:50:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5486568","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5486568","identity":"rs-5486568","version":["v1"]},"buildId":"veTbxFhMMB0_faC6-Wkog","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}