The livelihood of one in three people on earth depends on livestock and pastoralism. Especially in arid regions, which account for more than 40 percent of the planet’s land area, grazing is essential for survival.
Despite this importance for humans and nature, until recently there had been no global field study on the impact of pasture management on dryland performance. The Chair of Vegetation Ecology at the University of Tübingen therefore joined a research consortium of more than one hundred scientists who collected and analyzed data at 326 sites in drylands in 25 countries and on six continents. The study was published in November in the renowned journal Science .
We have been studying the effects of climate change on rarely explored drylands in Chile, Palestine and South Africa for years. This has enabled us to fill important gaps in the study’s data set," says Katja Tielbörger, head of the Department of Vegetation Ecology at the University of Tübingen.
Using a standardized method, scientists around the world, led by Spanish ecologist Fernando Maestre of the University of Alicante, investigated how increasing grazing pressure affects "ecosystem services". These services include soil fertility, erosion, climate regulation or tree cover and forage availability. The local climate, soil and biodiversity have a decisive influence.
However, these factors affect ecosystem performance differently depending on whether grazing pressure increases or decreases. As grazing pressure increases, the soil erodes more and its ability to store carbon decreases. This storage capacity, on the other hand, increases again through vegetation with vascular plants and through certain herbivorous mammals such as goats or sheep, provided that grazing pressure is not too high. Land management in drylands is therefore of great importance for climate protection. Our results show how important the conservation of biodiversity in drylands worldwide is for climate protection," says Liesbeth van den Brink, Post Doc in Tielbörger’s research group and co-author of the study.
The results of the study can help implement sustainable grazing management and provide guidance on what can be done to address climate change and the devastation of drylands.
The study was part of the BIODESERT project , for which Fernando T. Maestre received a Consolidator Grant from the European Research Council (ERC).
Maestre, F.T. et al. "Grazing and ecosystem service delivery in global drylands." Science (2022), abq4062