Earthworm communities in alluvial forests: Influence of altitude, vegetation stages and soil parameters

Abstract

a b s t r a c tIn many terrestrial ecosystems, soil parameters usually regulate the distribution of earthworm communities. In alluvial ecosystems, few studies have investigated the impact of periodic floods and alluvium deposition on soil fauna. In this context, we assumed that earthworm communities may vary depending on altitude (alpine, subalpine, mountain and hill levels), forest successional stage (post-pioneer to mature forests) and some soil parameters. Our results demonstrated that the composition of earthworm communities differed depending on altitudinal gradients. No earthworm was found at the alpine level while maximum density and biomass were observed at the hill level mainly due to the contribution of anecic species. A total of 27 species and subspecies were found over the three sampling sites, and Lumbricus moliboeus was discovered for the first time in carbonated soils. Soil texture had a major effect on epigeics that were often associated with coarse sandy texture in contrast to anecics which preferred deep soils and mature forest stages, which in combination provided the highest carbon content and the finest soil texture. In our study, carbonated fluviosols (Fluvisols according to the World Reference Base) were recorded; fluviosols typiques with well-structured A layers were generally found in mature or intermediate forest stages while most of fluviosols juveniles with heterogeneous texture were observed principally in post-pioneer forests. We conclude that in alluvial ecosystems, earthworm communities were highly dependent first on soil parameters, then altitude and to a lesser extent forest successional stages. Changes in earthworm communities tend to reflect a gradient of alluvial dynamics thus reinforcing the potential role of earthworms as bioindicators in natural and/or semi natural alluvial ecosystems.

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

“…Previous works showed that anecic species are strongly related to soil depth (Bouché, 1972;Guenat et al, 1999;Phillipson et al, 1976). Our study confirmed that A. c. nocturna and L. terrestris prefer thick soils as already shown by Salomé et al(2011) and, by extension, drier conditions; and provide evidence that A. longa adopts a similar behaviour. Among the three species, A. longa reached the highest abundance in HERBS and GRAVELS thus showing the greatest tolerance to flooding.…”

“…At the floodplain scale, the observed values for biomass, abundance, species richness, and diversity were similar to those recorded in comparable settings (Ivask et al, 2007;Plum and Filser, 2005;Salomé et al, 2011;Zorn et al, 2005) and testify from welldeveloped earthworm communities. The PCA and Monte Carlo tests (Fig.…”

“…Soil organisms include many potential indicators of river restoration success but this potential has not yet been studied much (Bullinger-Weber et al, 2007;Fournier et al, 2012;Guenat et al, 1999). Among the candidates, earthworms are recognised as good bioindicators of soil conditions in alluvial ecosystems (Bullinger-Weber et al, 2012;Salomé et al, 2011) and could therefore provide useful information for monitoring of restoration projects.…”

Effects of rubber leaf litter vermicompost on earthworm population and yield of pineapple (Ananas comosus) in West Tripura, India

“…Where significant factors were evident, Tukey's post hoc test (Tukey 1953) was applied to examine which particular means were significantly different at 5 % level of significance. A multivariate statistical technique, Principal component analysis (PCA) (Ammer et al 2006;Salome et al 2011) was performed to analyze the relationship of plant growth parameters, fruiting properties, earthworm density and biomass with the soil chemical properties. The original numbers of variables were summarized into a few principal components (PC) by means of PCA based on a correlation matrix (Moreira et al 2003).…”

Are urban soils similar to natural soils of river valleys?

“…Conversely, (2) young perturbed soils, mainly located in meadows and lawns, were shallower and were essentially formed by recent ex situ materials of different origins (e.g . Few studies reported similar trends in natural alluvial (Gerrard 1992;Bullinger-Weber and Gobat 2006;Salomé et al 2011) and urban soils (Bullock and Gregory 1991;Baumgartl 1998;Lefort et al 2007). For example, Lefort et al (2007) found higher sand, lower CEC and C org contents in human-made soils compared to natural or near natural urban soils.…”