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2016-12-01 | permalink
Land-use intensification leads to decline of species diversity, study
Flowering meadows are rich in species (Photo: CC0)
The intensification of land use is a major driver of biodiversity loss, ultimately leading to the homogenization of grassland communities, according to new research published Wednesday in the journal Nature. The study draws on research by a team of 300 scientists around lead author Martin Gossner from the Technical University of Munich (TUM). The scientists looked at the consequences of land-use intensification across different species groups, using data from 150 grassland areas collected since 2008 in Europe. They found that in areas with intensive use of grasslands, species diversity decreased and eventually only a small range of the same species remained. This threatens nature’s ability to provide valuable ecosystem services, ranging from soil formation for food production to pest control. For the study, more than 4,000 species were analyzed, using data from three regions in Germany with different conditions in terms of climate, geology, and topography, but similar forms of grassland management. According to the authors, their research is more comprehensive than previous studies which only focused on individual groups of species, such as birds within a particular habitat. The researchers looked at species ranging from single-celled organisms to vertebrates, including organisms below ground such as bacteria, fungi, and millipedes. “For the first time, we investigated all groups of species along the food chain on grasslands with different forms of land use in a variety of regions,” said Dr Gossner. The scientists analysed the impact of human land use, such as cutting grass, on the different species to see whether it made a difference if grass was cut twice or four times a year. They found that even a moderate use of meadows and pastures had a devastating effect on species diversity. “According to our observations, the homogenization of species does not progress proportionally to the intensity of use. Instead, even a moderate management of grassland results in cross-regional communities being reduced to the same, less demanding all-rounders,” said Gossner. This means that only those species will survive which do not have specific requirements regarding host plants or environmental conditions. The authors therefore highlight the need for more extensively managed grasslands in order to conserve multitrophic biodiversity and ecosystem service provision. “Interactions between plants and their consumers are increasingly weakened by intensive agricultural usage,” said Gossner. Thus, grassland areas that are cultivated extensively are key to protecting species diversity.
