Forest fragmentation and edge effects on the genetic structure of Clusia sphaerocarpa and C. lechleri (Clusiaceae) in tropical montane forests
Forest fragmentation and edge effects on the genetic structure of Clusia sphaerocarpa and C. lechleri (Clusiaceae) in tropical montane forests
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DOI：
10.1017/s0266467413000345
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发表时间：
2013-06
影响因子：
1.4
通讯作者：
Amira Apaza Quevedo;M. Schleuning;I. Hensen;F. Saavedra;W. Durka
中科院分区：
文献类型：
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作者：
Amira Apaza Quevedo;M. Schleuning;I. Hensen;F. Saavedra;W. Durka
摘要：热带森林的破碎化影响着植物种群遗传结构的非生物和生物过程。在森林碎片中，边缘效应，即森林边缘的非生物因子和生物因子的变化可能普遍存在。以玻利维亚热带山地森林的2个森林片段（面积约200 ha，海拔约2450 m）为研究对象，以雌雄异株树Clusia sphaerocarpa和c. lechleri的同域居群为研究对象，比较了边缘生境和内部生境的遗传多样性和小尺度遗传结构（SGS）。利用8个微卫星标记对球藻成虫、幼虫和幼苗343个个体和毛蚶196个个体进行了基因分型。两种植物的生境间（黄球藻ΦRT = 0.071, lechleri ΦRT = 0.028）和年龄间（黄球藻ΦRT = 0.016）存在遗传分化。总体而言，SGS效应较弱但显著，其中毛蚶（Sp = 0.0128）的SGS效应较球藻（Sp = 0.0073）更为显著。然而，正空间遗传自相关仅扩展到10 m。青松幼苗期和幼期的SGS效应强于成虫期，林内SGS效应强于林缘。我们的研究结果表明，边缘效应可以通过破坏局部遗传结构扩展到遗传水平，这可能是由于森林边缘基因流动的增加和授粉和种子传播相互作用的增强。
Abstract: Fragmentation of tropical forests influences abiotic and biotic processes that affect the genetic structure of plant populations. In forest fragments, edge effects, i.e. changes of abiotic and biotic factors at forest edges, may be prevalent. In two forest fragments (c. 200 ha at c. 2450 m asl) of tropical montane forest in Bolivia, sympatric populations of the dioecious tree species Clusia sphaerocarpa and C. lechleri were used as case study species to compare genetic diversity and small-scale genetic structure (SGS) between edge and interior habitats. Eight microsatellite markers were employed to genotype 343 individuals including adults, juveniles and seedlings of C. sphaerocarpa and 196 of C. lechleri. Genetic differentiation was found between habitats in both species (ΦRT = 0.071 for C. sphaerocarpa and ΦRT = 0.028 for C. lechleri) and among ages in C. sphaerocarpa (ΦRT = 0.016). Overall, SGS was weak but significant with more pronounced SGS in C. lechleri (Sp = 0.0128) than in C. sphaerocarpa (Sp = 0.0073). However, positive spatial genetic autocorrelation extended only up to 10 m. For C. sphaerocarpa, SGS was stronger in seedling and juvenile stages than in adults and in the forest interior than at forest edges. Our results show that edge effects can extend to the genetic level by breaking-up local genetic structures, probably due to increased gene flow and enhanced pollination and seed-dispersal interactions at forest edges.