Title: The Effect of Land Use on Water Quality and Associated Ecosystem Services as Indicated by Macroinvertebrates in the River Rur, Germany
Author: Nicolas Kigoonya
Supervising Institution: IHE Delft - Institute for Water Education
Modern land-use practices endanger the ecological integrity of lotic ecosystems, negatively affecting water quality and the provision of ecosystem services dependent on good water quality. Habitat provision is a water quality dependent ecosystem service and forms the basis for biodiversity. As water quality deteriorates, so do habitats, and ultimately biodiversity. Using benthic macroinvertebrates as indicators, this study was conducted on the river Rur in Germany, to determine the effect of land use on the water quality and habitats in the three sub-catchments of the Rur. These were along a gradient of increasing catchment area under agriculture and urbanization, the Upper Rur, Inde and Wurm. Macroinvertebrates were sampled and habitats scored using the Rapid Bio-assessment Protocol standard sampling method. The results show that the three major land uses (forestry, urbanization and agriculture) differently affect habitat and water quality. In keeping with the land use gradient, the Upper Rur had the highest habitat quality followed by the Inde and Wurm. On average, the Wurm and Upper Rur had the highest and least temperatures of 12.84 0C and 8.37 0C respectively, while the Inde showed the highest pH of 7.7 and electrical conductivity of 589.96 μs/cm. While the Wurm had the highest nitrate and phosphate concentrations, the Upper Rur had the least concentrations of the two nutrients. The Upper Rur also had the highest macroinvertebrate diversity of 2.30 ± 0.31 while the Wurm had the least (1.59 ± 0.50). Furthermore, the Upper Rur had the highest number of families (24), followed by Inde with 21. Whilst family Odontocentridae was only recorded in the Upper Rur, Siphlonuridae, Sericostimatidae and Glossosomatidae only the Upper Rur and Inde, families like Heptageniidae and Rhyacophilidae were recorded in all the sub-catchments. This study provides information on the impact of land use on the Rur’s ecosystem with an aim of embracing the goals of the Water Framework Directive and Habitat directive of the European Union and UN Sustainable Development Goal 14. The study further gives a translation of the effect of land use on the provision of ecosystem services associated with water quality.