KAUST study: Plant diversity protects drylands from grazing
A recent scientific study conducted by researchers at King Abdullah University of Science and Technology (KAUST) has demonstrated that plant diversity in rangelands is one of the most important factors that helps arid lands resist grazing pressures and maintain their ecological stability. The study explained that areas with a greater diversity of plant species are better able to maintain their vegetation cover even with increasing livestock populations.
The roots of the environmental challenge and the history of grazing in arid regions
Historically, human life in arid and semi-arid regions has been linked to grazing, one of the oldest agricultural activities known to humankind. Over time, drylands have formed a harsh environment requiring unique adaptations from living organisms. However, population growth and increased demand for food resources have led to unprecedented intensification of grazing in recent decades, resulting in the degradation of vast areas of land and the emergence of desertification as one of the most serious environmental challenges of our time. This historical context makes understanding the mechanisms of resilience in these ecosystems an urgent necessity to ensure their sustainability.
Study results and global scope
The results of this groundbreaking study, published in the journal *Nature Ecology & Evolution*, were based on extensive field data collected from 73 sites in 25 countries across six continents. The study encompassed diverse ecosystems, including grasslands, plains, shrublands, and savannas, where researchers compared areas subjected to low grazing levels with those under high grazing pressure. The findings showed that increased grazing intensity led, in most cases, to an average 35% reduction in vegetation cover, although this reduction was not uniform across all sites.
How does plant diversity enhance resilience strategies?
When analyzing the various factors that might influence this phenomenon, such as rainfall, temperature, soil characteristics, and livestock type, plant diversity emerged as the most influential factor in an ecosystem's resilience. Areas with a greater number of plant species were less susceptible to vegetation loss with increased grazing. Lucio Biancari, a KAUST researcher and co-author of the study, explained that the different strategies plants use to cope, recover, and avoid grazing help distribute the stress across different species. Some species can tolerate grazing, while others have a high capacity for regeneration, and animals may avoid certain species. When these diverse plant species are present together, the impact of grazing is distributed rather than concentrated on a single species.
Strategic dimensions and expected impacts locally and internationally
These findings are of paramount importance at all levels. Internationally, drylands are vital for livestock production, supporting nearly half of the world's livestock output and providing a livelihood for approximately one billion people. They also play a crucial role in soil stabilization and carbon sequestration. At the local and regional levels, the study is particularly relevant to Saudi Arabia and the Middle East, where drylands cover vast areas and grazing is a primary activity. These scientific findings provide a solid foundation for supporting environmental initiatives and combating desertification by focusing on cultivating diverse, native species to ensure rangeland sustainability and food security.
Towards sustainable management of natural rangelands
These findings come at a crucial time, as the United Nations has declared 2026 the International Year of Rangelands and Pastoralists, aiming to highlight globally the importance of natural rangelands and the need for their sustainable management. Professor Fernando Maestri, an environmental scientist at KAUST and the study's lead author, emphasized that ecosystems with greater plant diversity are better able to distribute environmental stress, while reduced diversity leads to faster degradation. This research will help policymakers and stakeholders develop better policies for rangeland management and the restoration of degraded lands, thus preserving natural resources for future generations.
