Huang Siyu, Feigs Jannis Till, Holzhauer Stephanie I J, Kramp Katja, Brunet Jörg, Decocq Guillaume, De Frenne Pieter, Diekmann Martin, Liira Jaan, Spicher Fabien, Vangansbeke Pieter, Vanneste Thomas, Verheyen Kris, Naaf Tobias
Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg Germany.
Southern Swedish Forest Research Centre Swedish University of Agricultural Sciences Lomma Sweden.
Ecol Evol. 2024 Feb 26;14(2):e10971. doi: 10.1002/ece3.10971. eCollection 2024 Feb.
Due to multiple land-cover changes, forest herb populations residing in forest patches embedded in agricultural landscapes display different ages and, thus, experience differences in genetic exchange, mutation accumulation and genetic drift. The extent of divergence in present-day population genetic structure among these populations of different ages remains unclear, considering their diverse breeding systems and associated pollinators. Answering this question is essential to understand these species' persistence, maintenance of evolutionary potential and adaptability to changing environments. We applied a multi-landscape setup to compare the genetic structure of forest herb populations across forest patches of different ages (18-338 years). We studied the impact on three common slow-colonizer herb species with distinct breeding systems and associated pollinators: (outcrossing, long-distance pollinators), (outcrossing, short-distance pollinators) and (mixed breeding). We aimed to assess if in general older populations displayed higher genetic diversity and lower differentiation than younger ones. We also anticipated that would show the smallest while the largest difference, between old and young populations. We found that older populations had a higher observed heterozygosity ( ) but a similar level of allelic richness ( ) and expected heterozygosity ( ) as younger populations, except for , which exhibited higher and in younger populations. As populations aged, their pairwise genetic differentiation measured by decreased independent of species identity while the other two genetic differentiation measures showed either comparable levels between old and young populations ( ) or inconsistency among three species (). The age difference of the two populations did not explain their genetic differentiation. Synthesis: We found restricted evidence that forest herb populations with different ages differ in their genetic structure, indicating that populations of different ages can reach a similar genetic structure within decades and thus persist in the long term after habitat disturbance. Despite their distinct breeding systems and associated pollinators, the three studied species exhibited partly similar genetic patterns, suggesting that their common characteristics, such as being slow colonizers or their ability to propagate vegetatively, are important in determining their long-term response to land-cover change.
由于多种土地覆盖变化，栖息在农业景观中嵌入的森林斑块中的森林草本植物种群呈现出不同的年龄，因此，在基因交换、突变积累和遗传漂变方面存在差异。考虑到这些不同年龄种群的多样繁殖系统和相关传粉者，目前这些不同年龄种群之间的种群遗传结构差异程度仍不清楚。回答这个问题对于理解这些物种的持久性、进化潜力的维持以及对不断变化环境的适应性至关重要。我们采用多景观设置来比较不同年龄（18 - 338年）森林斑块中森林草本植物种群的遗传结构。我们研究了对三种具有不同繁殖系统和相关传粉者的常见缓慢定居草本物种的影响：（异交，长距离传粉者）、（异交，短距离传粉者）和（混合繁殖）。我们旨在评估一般来说，老龄种群是否比年轻种群具有更高的遗传多样性和更低的分化程度。我们还预期在老龄和年轻种群之间，将表现出最小的差异，而将表现出最大的差异。我们发现，老龄种群具有更高的观察杂合度（），但等位基因丰富度（）和预期杂合度（）水平与年轻种群相似，除了，其在年轻种群中表现出更高的和。随着种群年龄增长，通过测量的成对遗传分化与物种身份无关而降低，而其他两种遗传分化测量方法显示老龄和年轻种群之间要么水平相当（），要么在三个物种之间不一致（）。两个种群的年龄差异并不能解释它们的遗传分化。综合：我们发现有限的证据表明不同年龄的森林草本植物种群在遗传结构上存在差异，这表明不同年龄的种群在几十年内可以达到相似的遗传结构，从而在栖息地干扰后长期持续存在。尽管这三种研究物种具有不同的繁殖系统和相关传粉者，但它们表现出部分相似的遗传模式，这表明它们的共同特征，如作为缓慢定居者或其无性繁殖能力，在决定它们对土地覆盖变化的长期反应中很重要。
