Karbstein Kevin, Römermann Christine, Hellwig Frank, Prinz Kathleen
Institute of Ecology and Evolution Friedrich Schiller University Jena Germany.
Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium) Albrecht-von-Haller Institute for Plant Sciences University of Göttingen Göttingen Germany.
Ecol Evol. 2023 Aug 7;13(8):e10376. doi: 10.1002/ece3.10376. eCollection 2023 Aug.
Population size, genetic diversity, and performance have fundamental importance for ecology, evolution, and nature conservation of plant species. Despite well-studied relationships among environmental, genetic, and intraspecific trait variation (ITV), the influence of population size on these aspects is less understood. To assess the sources of population size variation, but also its impact on genetic, functional trait, and performance aspects, we conducted detailed population size estimations, assessed 23 abiotic and biotic environmental habitat factors, performed population genetic analyses using nine microsatellite markers, and recorded nine functional traits based on 260 individuals from 13 semi-dry grassland locations of Central Europe. Modern statistical analyses based on a multivariate framework (path analysis) with preselected linear regression models revealed that the variation of abiotic factors (in contrast to factors per se) almost completely, significantly explained fluctuations in population size ( = .93). In general, abiotic habitat variation (heterogeneity) was not affected by habitat area. Population size significantly explained genetic diversity ( : = .42, : = .67, : = .43, and : = .59), inbreeding ( : = .35), and differentiation ( : = .20). We also found that iFD (ITV) was significantly explained by abiotic habitat heterogeneity, and to a lesser extent by genetic diversity ( = .81). Nevertheless, habitat heterogeneity did not statistically affect genetic diversity. This may be due to the use of selectively neutral microsatellite markers, and possibly by insufficient abiotic selective pressures on habitats examined. Small populations in nonoptimal habitats were characterized by reduced genetic and functional trait diversity, and elevated genetic inbreeding and differentiation. This indicates reduced adaptability to current and future environmental changes. The long-term survival of small populations with reduced genetic diversity and beginning inbreeding will be highly dependent on habitat protection and adequate land-use actions.
种群大小、遗传多样性和表现对于植物物种的生态、进化和自然保护具有根本重要性。尽管环境、遗传和种内性状变异（ITV）之间的关系已得到充分研究，但种群大小对这些方面的影响仍了解较少。为了评估种群大小变异的来源及其对遗传、功能性状和表现方面的影响，我们进行了详细的种群大小估计，评估了23个非生物和生物环境栖息地因素，使用9个微卫星标记进行了种群遗传分析，并基于来自中欧13个半干旱草原地点的260个个体记录了9个功能性状。基于具有预选线性回归模型的多变量框架（路径分析）的现代统计分析表明，非生物因素的变异（与因素本身相反）几乎完全、显著地解释了种群大小的波动（r² = 0.93）。一般来说，非生物栖息地变异（异质性）不受栖息地面积的影响。种群大小显著解释了遗传多样性（r²：r² = 0.42，r² = 0.67，r² = 0.43，r² = 0.59）、近亲繁殖（r²：r² = 0.35）和分化（r²：r² = 0.20）。我们还发现，iFD（ITV）由非生物栖息地异质性显著解释，在较小程度上由遗传多样性解释（r² = 0.81）。然而，栖息地异质性在统计上并未影响遗传多样性。这可能是由于使用了选择性中性微卫星标记，也可能是由于对所研究栖息地的非生物选择压力不足。非最佳栖息地中的小种群具有遗传和功能性状多样性降低、遗传近亲繁殖和分化增加的特征。这表明对当前和未来环境变化的适应性降低。遗传多样性降低且开始出现近亲繁殖的小种群的长期生存将高度依赖于栖息地保护和适当的土地利用行动。
