Colonisation of secondary habitats in mining sites by Labidura riparia (Dermaptera: Labiduridae) from multiple natural source populations

Mareike Gueth,Walter Durka,Gerhard Wiegleb

doi:10.1007/s10841-021-00305-y

Abstract

BackgroundOpen 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 Labidurariparia, 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.MethodsUsing 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.ResultsGenetic 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 (FST = 0.08; FʹST = 0.253), with stronger differentiation among primary (FST = 0.196; FʹST = 0.473) than among secondary habitats (FST = 0.043; FʹST = 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.DiscussionPopulations 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 conservationA 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.

Highlights

Biodiversity is threatened globally and locally by human activities in various ways especially habitat destruction, fragmentation, pollution or climate change (Cardoso et al 2020)
We addressed the following questions: (1) Does genetic diversity of earwig populations differ between natural habitats and secondary sites? (2) Are the populations genetically structured, and is genetic differentiation related to geographic distance? (3) Can a single or multiple source regions be identified for colonisation of secondary habitats? (4) What are the consequences for conservation?
The populations were highly diverse with mean number of alleles ranging from 3.9 to 7.2, and mean A = 5.7, allelic richness ranging from 3.2 to 4.8, with mean Ar = 4.2 and expected heterozygosity ranging from 0.569 to 0.748 with mean He = 0.688

Summary

Introduction

Biodiversity is threatened globally and locally by human activities in various ways especially habitat destruction, fragmentation, pollution or climate change (Cardoso et al 2020). Lignite open cast mining in Central and East Germany resulted in dumping nutrient-poor sandy substrates over large areas (Hildmann and Wünsche 1996; Wiegleb et al 2000). The colonisation of arthropods on such sites and patterns of succession have been intensively studied (e.g. Neumann 1971; Dunger 1991; Brunk 2007) Due to their mere size, the lack of ongoing anthropogenic impact small-scale heterogeneity of abiotic conditions, post-mining landscapes can harbour a rich fauna and flora and can be of high value for conservation (Brändle et al 2000; Tischew 2004; Dolezalova et al 2012). Since the species is adapted to ephemeral sandy habitat, the newly established sites may have been continuously colonised from a meta-population that existed prior to mining activities, resulting in low levels of genetic differentiation among both old and new populations. We addressed the following questions: (1) Does genetic diversity of earwig populations differ between natural habitats and secondary sites? (2) Are the populations genetically structured, and is genetic differentiation related to geographic distance? (3) Can a single or multiple source regions be identified for colonisation of secondary habitats? (4) What are the consequences for conservation?

Materials and methods

21 Sondershausen

Results

Discussion