The livelihood of one in three people on earth depends on livestock and pastoralism. Especially in dry areas, which make up more than 40 percent of the land area of our planet, pastoralism is essential for survival.
Despite this importance for humans and nature, until recently there had been no global field study of the impact of pastoralism on dryland performance. The Chair of Vegetation Ecology at the University of Tübingen has therefore joined a research network of over 100 scientists who have collected and evaluated data at 326 locations in arid regions 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 dry areas in Chile, Palestine and South Africa for years. This enabled us to fill important gaps in the study’s data set,” said Professor Katja Tielbörger, head of the Chair of Vegetation Ecology at the University of Tübingen.
Using a standardized procedure, scientists led by the Spanish ecologist Fernando Maestre from the University of Alicante worldwide investigated the question of how increasing grazing pressure affects the “services of the ecosystem”. These services include soil fertility, erosion, regulation of climate or tree cover, and availability of forage crops. The local climate, soil and biodiversity have a decisive influence.
However, these factors affect ecosystem performance differently depending on whether grazing pressure is increasing or decreasing. With increasing grazing pressure, the soil erodes more and its ability to store carbon decreases. On the other hand, this storage capacity increases again through the growth of vascular plants and through certain herbivorous mammals such as goats or sheep, provided that the grazing pressure is not too high. Land management in dry areas is therefore of great importance for climate protection. “Our results show how important it is to preserve biodiversity in dry regions worldwide for climate protection,” says Liesbeth van den Brink, postdoc in Professor Tielbörger’s working group and co-author of the study.
The results of the study can help with the implementation of sustainable pasture management and provide indications of what can be done to combat climate change and the devastation of dry areas.
