Short-term population dynamics of Coreanomecon hylomeconoides, an endemic plant species in Korea

Abstract

Predicting the effects of climate change on plant species and developing practical strategies that could mitigate anticipated negative impacts of climate change is a critical challenge for ecologists. Since environmental changes directly affect population dynamics through altered vital rates, predicting how species will respond and guiding management to climate change requires a clear understanding of how natural population dynamics are changing in response to environmental variations. Given that endemic plant species are considered more vulnerable to climate change than other comparable species, it is necessary to prioritize the determination of population dynamics for conservation efforts. This study characterized the short-term population dynamics of Coreanomecon hylomeconoides, an endemic perennial plant in Korea, using demographic models, MPM, and IPM. To investigate the population dynamics of C. hylomeconoides, demographic surveys were conducted for two years (2022-2023) at seven different sites that could cover the overall distribution range of C. hylomeconoides. Our analysis showed general maintenance or a slight increase in the population size of C. hylomeconoides across its geographic range. However, its narrow geographic range, small population size, and strong dependence on a few reproductive adults can lead to a high extinction risk, suggesting that continuous management and monitoring are necessary. The LTRE analysis revealed that spatial variation in population growth rates (λ) for C. hylomeconoides was mainly attributed to establishment. In addition, precipitation and pH were significantly correlated with λ and again marginally correlated with establishment, suggesting that variations in establishment due to variations in precipitation and pH may have a significant impact on the observed spatial variation in λ. This implies that the precipitation and pH can have a significant impact on the population size of C. hylomeconoides. Therefore, a quantitative assessment of the effect of precipitation and pH on C. hylomeconoides is necessary in the future to predict the response or distribution of C. hylomeconoides and establish a comprehensive conservation strategy for climate change. Negative correlations between different vital rates, which can reduce variance in λ, were also observed. Notably, the negative correlation between growth and fruit production, as well as the negative correlation between flowering and establishment, may reflect the trade-offs between life history functions and the negative effects of adults on the establishment, respectively. Demographic perturbation analysis highlighted that the future population viability of C. hylomeconoides largely depends on the survival of adult plants. This suggests that for effective species management, it may be necessary to enhance the number of adult plants and protect all the existing adults. Furthermore, seedling establishment was most crucial in some populations, but in the case of the HD population, it seems that the population was maintained by seeds introduced externally rather than those produced within the plot. Thus, to assess the importance of establishment correctly, it is necessary not only to understand the seed dispersal mechanisms among populations but also to conduct a more extensive investigation within the same region. Our study provides fundamental information for predicting responses to environmental variability and guiding management for rare plant species. However, despite the many studies suggesting that spatial and temporal variation affect population dynamics in very different ways, our study only includes spatial variation for the population. In this context, for a more comprehensive understanding of population dynamics, further long-term demographic surveys may be necessary to understand the response of populations to environmental variability over time.