Data from: Landscape composition has limited impact on local genetic structure in mountain clover, Trifolium montanum L.

Semi-dry grasslands in the European Alps have been increasingly fragmented over the last 150 years. Few studies have investigated the implications of landscape configuration for genetic structure and gene flow among remnant habitat patches. Conservation management of semi-dry grassland plants rarely accounts for possible effects of major landscape elements; such as forest patches, as barriers to gene flow and dispersal via seed and pollen, despite their potential importance for biodiversity conservation. Using 1,416 individuals from 61 sampling sites across two valleys in South-Eastern Switzerland and AFLP fingerprints we applied a spatial strip and a circle approach to determine the impact of different landscape elements on genetic differentiation in the semi-dry grassland herb Trifolium montanum (mountain clover). Overall genetic differentiation among sampling sites was low (overall FST = 0.044). Forest area had no effect on gene flow at the landscape scale but area of semi-dry grassland, the potential habitat of T. montanum, road area and altitude influenced genetic differentiation among sampling sites. The observed pattern of genetic differentiation suggests that a future increase in forest area, due to land use abandonment, at least in the short term, are unlikely to directly impact patterns of genetic variation in T. montanum.

过去150年间，欧洲阿尔卑斯山区的半干燥草原（semi-dry grassland）日益破碎化。迄今鲜有研究探讨景观格局对残存生境斑块间遗传结构与基因流的影响。尽管森林斑块等大型景观要素对生物多样性保护具有潜在重要性，但半干燥草原植物的保护管理极少将其作为基因流与种子、花粉传播的障碍纳入考量。本研究采集瑞士东南部两个山谷内61个采样点的1416个个体，结合扩增片段长度多态性（Amplified Fragment Length Polymorphism，AFLP）指纹图谱，采用空间样带法与圆形窗口法，探究了不同景观要素对半干燥草原草本植物山地三叶草（Trifolium montanum，mountain clover）遗传分化的影响。采样点间的整体遗传分化程度较低（整体固定指数Fixation Index，FST=0.044）。在景观尺度上，森林面积对基因流无显著影响，但山地三叶草的潜在生境——半干燥草原面积、道路面积与海拔，均对采样点间的遗传分化存在显著影响。本研究观测到的遗传分化模式表明，未来因土地撂荒导致的森林面积扩张，至少在短期内，不会直接对山地三叶草的遗传变异模式产生影响。