Hydrological and vegetation analysis of an alluvial floodplain in Belgium

In this paper, results from an intensive two-year monitoring campaign of a wetland gradient are presented and analyzed. Two spatially adjacent sites along a wetland gradient are described by means of abiotic variables, groundwater level, and soil temperature and soil moisture at several depths throughout the vertical soil profile. The vegetation of the sites is described on the basis of a species cover inventory, and two different vegetation types are distinguished along the wetland gradient: Arrhenatheretum elatioris at the highest end of the gradient and Caricetum gracilis at the lowest end. Aboveground biomass and leaf area index of both Arrhenatheretum elatioris and Caricetum gracilis were measured on a monthly basis, and their seasonal variation could be related to specific site conditions. Furthermore, evidence was found that vegetation was not passive to the environmental site conditions but actively influenced them. The groundwater at the lower Caricetum gracilis site showed diurnal fluctuations with amplitudes up to 10 cm, which could be attributed to transpiration losses by phreatophytes.

Publication year:2009