Impact of soil properties on plant community composition in riparian forests near Bratislava

Wien

2014

Artikel aus einer ZeitschriftUnselbständiges Werk

17215

200189730

Natural flood plains are among the Earth’s most biologically productive and diverse ecosystems. At the same time, they are threatened on a global scale, being sensitive towards anthropogenic impacts such as river regulations and silvicultural management practises, which in turn may alter plant species composition. Yet, one of the most distinctive features of flood plains is the high spatial variability of soils due to hydrological (e.g. flood pulse) and geomorphological processes (e.g. sedimentation and erosion) which may also influence plant species composition. In an interdisciplinary study linking plant sociology and soil characterisation we therefore aimed at clarifying which abiotic factors have the most decisive impact on plant species composition at even a small spatial scale. Six Populus alba communities south-east of Bratislava exhibiting significant differences in plant species composition of the herbaceous layer were studied from a phytosociological and physicochemical point of view. Of these six sites, one is still flooded periodically and three are silviculturally managed. Multivariate analyses of variance (MANOVA) showed significant differences between the sites regarding soil nutrient stocks, soil texture as well as water retention characteristics. Principal component analysis (PCA) based on the phytosociological relevés revealed soil moisture and nutrient gradients as well as solar shading as principal components. Biogeochemical-mechanistic ecosystem modelling on the basis of data from 2000 to 2011 also emphasised discriminating effects of soil texture. Plant species composition (65 different plant species) was related to the measured environmental parameters using canonical correspondence analysis (CCA). Clustering of sites within the CCA and PCA plots has lead us to distinguish between two habitats among the six sites: floodplains offering (a) moister and more nutrient-rich conditions and (b) seasonally dryer and nutrient-poorer conditions. Our study therefore highlights that the nature of soil, shaped by its physicochemical properties, plays a key role in determining plant community composition at a small spatial scale.