Background

Open cast lignite mines, sand pits and military training areas represent human-made, secondary habitats for specialized xerothermophilous and psammophilous species. Rare species, including the earwig Labidura riparia, are found in high population densities in such sites. However, it is unknown from which sources colonisation took place and how genetic variation compares to that of ancient populations on natural sites.

Methods

Using nine microsatellite markers, we analysed genetic variation and population structure of L. riparia in 21 populations in NE Germany both from secondary habitats such as lignite-mining sites, military training areas and a potassium mining heap, and rare primary habitats, such as coastal and inland dunes.

Results

Genetic variation was higher in populations from post-mining sites and former military training areas than in populations from coastal or inland dune sites. Overall population differentiation was substantial (F_ST = 0.08; Fʹ_ST = 0.253), with stronger differentiation among primary (F_ST = 0.196; Fʹ_ST = 0.473) than among secondary habitats (F_ST = 0.043; Fʹ_ST = 0.147). Differentiation followed a pattern of isolation by distance. Bayesian structure analysis revealed three gene pools representing primary habitats on a coastal dune and two different inland dunes. All populations from secondary habitats were mixtures of the two inland dune gene pools, suggesting multiple colonization of post-mining areas from different source populations and hybridisation among source populations.

Discussion

Populations of L. riparia from primary habitats deserve special conservation, because they harbour differentiated gene pools. The majority of the L. riparia populations, however, thrive in secondary habitats, highlighting their role for conservation.

Implications for insect conservation

A dual strategy should be followed of conserving both remaining natural habitat harbouring particular intraspecific gene pools and secondary habitat inhabited by large admixed and genetically highly variable populations.

中文翻译：

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Labidura riparia（Dermaptera：Labiduridae）在多个自然资源种群中对采矿场所次生栖息地的定殖

背景

露天褐煤矿，沙坑和军事训练区代表了专门用于干性和嗜湿性物种的人工次生栖息地。在这些地方的高种群密度中发现了稀有物种，包括ear Labidura riparia。但是，尚不清楚从哪个来源进行殖民，以及如何将遗传变异与自然地点的古代种群进行比较。

方法

我们使用9个微卫星标记，分析了德国东北部21个种群中褐腐乳草的遗传变异和种群结构，这些种群来自褐煤开采场，军事训练区和钾矿堆等次生生境，以及沿海等稀有的主要生境和内陆沙丘。

结果

采后地点和前军事训练区的种群遗传变异高于沿海或内陆沙丘地点的种群遗传变异。整体种群分化是相当大（˚F _ST  = 0.08; F' _ST  = 0.253），与初级之间更强的分化（˚F _ST  = 0.196; F' _ST  = 0.473）比仲栖息地（间˚F _ST  = 0.043; F' _ST = 0.147）。区分遵循距离隔离的模式。贝叶斯结构分析揭示了三个基因库，分别代表沿海沙丘和两个不同的内陆沙丘上的主要栖息地。来自次生栖息地的所有种群都是两个内陆沙丘基因库的混合物，这表明来自不同来源种群的采矿后地区会发生多次殖民化，并会在来源种群之间发生杂交。

讨论

种群L.河岸从主要栖息地值得特别保护的，因为他们怀有分化的基因库。然而，大多数河岸乳杆菌种群在次生栖息地繁衍生息，突显了它们在保护方面的作用。

对昆虫保护的意义

应该遵循双重策略，既要保护保留有特定种内基因库的剩余自然栖息地，又要保护由大量混杂的和遗传上高度可变的种群居住的次生栖息地。