Patterns of earthworm communities and species traits in relation to the perturbation gradient of a restored floodplain

Abstract

a b s t r a c tLittle is known about the diversity and ecology of earthworms in floodplains, as well as their response to natural and anthropic perturbations (e.g. floods, river channelisation, floodplain restoration). We characterised the patterns of earthworm communities and species traits in the different habitats of a lowland restored floodplain in Switzerland. In addition to classical species-based metrics, such as species richness and Shannon diversity, species traits were used to calculate the community weighted means (CWMs) of traits and functional dispersion (FDis). We hypothesised that trait-based metrics would reveal clearer patterns than classical approaches. The distribution of earthworm traits varied among habitats in relation to changes in flooding frequency: poorly developed gravel bar soils most exposed to flooding were characterised by high abundance of small epigeic species and low abundance of large anecic species. Differences in anecic and endogeic earthworm community structure matched flood frequency. In agreement with our hypothesis, CWMs were more strongly correlated to environmental variables than species composition, diversity, or functional diversity. Based on these results, the ratio of the relative abundances of epigeic and anecic species, and the differences in species composition within anecic and endogeic ecological types of earthworms were identified as indicators of soil development in floodplains.

Anecic earthworms (Lumbricus terrestris) alleviate negative effects of extreme rainfall events on soil and plants in field mesocosms

“…Such increased burrowing activity could be due to a facilitative effect of intense rainfall (i.e., conditions were favourable for digging), or on the contrary it could indicate that the earthworms were stressed by the disturbance and tried to escape or improve their habitat conditions. Regarding L. terrestris survival and growth, it has been shown that high soil moisture may be favourable (Berry and Jordan 2001), while prolonged flooding is detrimental (Fournier et al 2012).…”

Can soil testate amoebae be used for estimating the time since death? A field experiment in a deciduous forest

“…High N0 indicates a large number of species and high N2 a large number of species evenly distributed. Strong relations between N0 and N2 and environmental conditions were demonstrated at various spatial scales [34] and in a broad range of ecosystems such as tropical forest [35], marine ecosystems [36] and flood or fire prone ecosystems [28,37,38]. N0 and N2 were calculated for each treatments and time step.…”

Morphological, hydrological, biogeochemical and ecological changes and challenges in river restoration – the Thur River case study

“…In order to improve understanding of how hydromorphological variability relates to ecosystem functioning and services, terrestrial biodiversity as well as ground-and surface Huber et al, 2012;Shrestha et al, 2014) and (F) biodiversity surveys (for exact locations see Fournier et al, 2012b). The picture was taken by BHAteam, Frauenfeld.…”