13. Livestock Grazing, the Neglected Land Use

Livestock production plays a key role in national and regional economies, for food security and poverty alleviation, the climate system, biodiversity, and the biogeochemical cycles of carbon, nitrogen and water. In the near future, the importance of livestock is bound to increase due to anticipated economic developments and associated changes in human diets in many parts of the world as well as the need to feed a growing, increasingly urbanized world population. Ruminant livestock production occurs on grazing lands that extend over approximately one-third of the terrestrial ice-free surface. In addition, a significant proportion of cropland produce is used as feedstock for animals, whether monogastric or ruminant species. Despite this central role of livestock and grazing in the Earth system, datasets that would allow for systematic, comprehensive analyses are extremely scarce, if not nonexistent, and prone to extreme uncertainties. The largest data gaps relate to the extent and intensity of grazing activities. Furthermore, no statistics are available that allow an assessment of the amount of biomass that is harvested each year on grazing lands. In this contribution, we provide examples of how the socioecological method inventory can improve the knowledge base for grazing by, for example, allowing researchers to make a robust approximation of biomass flows due to grazing and to estimate the extent and intensity of grazing land use. Based on empirical analyses, we elaborate on the current state of research on global grazing, identify important uncertainties and outline possible contributions of socioecological research to this neglected but central aspect of global land use.