Effect of different restoration approaches on two species of newts (Amphibia: Caudata) in Central European lignite spoil heaps
Abstract
Post-mining sites often offer secondary habitats for various amphibians endangered in common agricultural landscapes. On the other hand, there is a general lack of quantitative studies on the effects of the common restoration practices on colonisation of such artificial freshwater habitats by amphibians.
Here, we focus on two newts decreasing in Central Europe, Lissotriton vulgaris and Triturus cristatus, in pools within lignite (brown coal) spoil heaps in the western Czech Republic. We compared their abundances in pools established by technical reclamation, spontaneous succession, and their combination.
In spring 2016, we sampled 29 freshwater pools in five spoil heaps and 10 fishponds in the surrounding agricultural landscape by funnel trapping. We captured 52 L. vulgaris and 138 T. cristatus in all the studied habitats together.
As only two L. vulgaris and no T. cristatus were caught in fishponds, the high potential of pools in post-mining landscapes was confirmed. Both newt species generally avoided the artificially established pools, but the spontaneously established pools were equally suitable for them in both technically reclaimed and spontaneously developed heaps.
L. vulgaris preferred more transparent water, higher cover of cattails and the pool placed in the forest, but with fewer trees on the pool banks, whilst T. cristatus preferred narrower zone of littoral vegetation, more trees on the pool banks, smaller water bodies and absence of fish. Such habitat preferences fully corroborate with natural habitats.
The technical reclamation still prevails in restoration of post-mining sites in many regions. We reveal it is an unsuitable practice for amphibians, if not combined with natural succession processes.