ACCURATE ENVIRONMENTAL BIOINDICATION IN FLOODPLAINS IN SPITE OF AN EXTREME FLOOD EVENT

作者：Follner Klaus^*; Hofacker Anke; Glaeser Judith; Dziock Frank; Gerisch Michael; Foeckler Francis; Ilg Christiane; Schanowski Arno; Scholz Mathias; Henle Klaus

来源：River Research and Applications, 2010, 26(7): 877-886.

DOI：10.1002/rra.1300

• bioindicator system
• carabid beetles
• groundwater depth
• inundation
• molluscs
• plants
• robustness
• site conditions

The ecological reaction of species on environmental factors can differ both, temporally and geographically. Therefore, bioindicator systems must be shown to remain accurate at different places and points of time. Extreme events pose challenges for testing this robustness, which has not yet been explored systematically. The unique opportunity of the extreme flooding of the river Elbe in August 2002 was used for such a test. The bioindicator system for mean groundwater depth during the vegetation period and annual duration of inundation in floodplains studied here was developed with data collected in 1999. Data from 2003 were used to analyse the dependence of the bioindication results on the humidity of the study plots and taxonomic group (plants, molluscs and carabid beetles). For the duration of inundation, the accuracy of bioindication in 2003 was similar to that in 1999, except for the medium-humid and dry plots using molluscs as indicators. For groundwater depth, the accuracy of bioindication in 2003 was similar to that of the reference year except in the dry plots with significantly lower accuracy for all species groups. With a few exceptions, the bioindicator system is shown to be robust and to remain accurate in spite of an extreme flood event. In conclusion, the relevance of extreme events for the robustness of bioindicator systems differs between the indicated parameters and taxonomic groups. The results stress the need to take into account the limits of the working range and the occurrence of extreme events, when testing and applying bioindicator systems.

• 出版日期2010-9