Railway tracks can have great value for butterflies as a new alternative habitat

K Kalarus,M Bąkowski

doi:10.1080/11250003.2015.1078417

Abstract

Natural and semi-natural habitats are declining. However, little is known of the value of artificial and human-altered habitats for biodiversity maintenance in fragmented landscapes. We hypothesized that railway tracks can have great value for butterflies as an alternative habitat. Using 200-m-long transects, we investigated species richness and two main types of β-diversity, i.e. nestedness and community dispersion, for both butterflies and their nectar plants in eight sites under an expected gradient of habitat quality – meadows, railway tracks, forest clearings and degraded meadows. Railway tracks and meadows had higher butterfly species richness than forest clearings and degraded meadow. Butterfly species distribution among sites was strongly related to the gradient of habitat quality that was measured as nectar plant composition. Railway tracks contained the widest pool of butterflies with species of various biotopes as well as a wide pool of nectar plants at a nested subset pattern of β-diversity. However, the pattern of community dispersion was opposite to what had been expected. Meadows and railway tracks, being more heterogeneous sites in terms of composition of nectar plants, supported slightly more homogeneous butterfly communities. This suggests that habitats of low quality, i.e. forest clearings and degraded meadows, have less-stable butterfly communities. We concluded that railway tracks located on sun-warmed embankments containing a reach pool of nectar plants could enable multi-species communities to persist in an environment of good suitability. Conservation managers should therefore focus on enhancing the quality of railway tracks and their vicinity through the preservation of a high abundance of various flowering plants.

Highlights

Habitat fragmentation is one the most relevant causes of rapid and global change in the natural environment
Bootstrap t-tests revealed that the group of sites containing meadows and railway tracks had greater species richness of both butterflies (t = 5.538, P = 0.003) and nectar plants (t = 3.927, P = 0.009) than the group containing forest clearings and degraded meadow
The order of sites generally revealed that forest clearings and degraded meadow are subsets of railway track and meadows in terms of both butterfly species composition and composition of nectar plant species (Figure 1a and Figure 2)

Summary

Introduction

Habitat fragmentation is one the most relevant causes of rapid and global change in the natural environment. In Europe, xerothermic grasslands and meadows are among the most important habitats for biodiversity preservation, and they are inhabited by many species, including butterflies such as umbrella Maculinea Phengaris) butterflies and other species, listed in the Habitats Directive (WallisDeVries et al 2002; Wynhoff et al 2011; Van Swaay et al 2012). The aforementioned habitats are declining and endangered (WallisDeVries et al 2002; Wynhoff et al 2011). Schtickzelle et al 2006; Bąkowski et al 2010; Wynhoff et al 2011; Kalarus et al 2013); other common and widespread species are in decline (Van Dyck et al 2009). The conservation of multispecies communities has become problematic and challenging (Settele et al 2009)

Methods

Results

Conclusion