Grazing lands are vast ecological areas defined as any land used for grazing livestock, whether by domestic animals or wild herbivores. These landscapes are typically dominated by grasses, forbs, and shrubs, covering approximately 40 to 50 percent of the Earth’s terrestrial surface. They perform numerous ecosystem services that are fundamental to planetary health, extending far beyond simply supporting livestock.
Rangelands vs. Pasturelands
Grazing lands are classified into two categories: rangelands and pasturelands, differentiated primarily by vegetation and management intensity. Rangelands are expansive areas characterized by native, non-cultivated vegetation. They are managed extensively, often by controlling animal numbers or using prescribed fire to regulate plant growth. Rangelands are generally found in regions of marginal agricultural use, such as deserts, savannas, shrublands, and steppes, and typically support a lower stocking density of livestock.
Pasturelands, conversely, are lands intentionally seeded, often with introduced forage species like specialized grasses or legumes. These systems are intensively managed using agronomic practices, including seeding, irrigation, and the application of fertilizers to enhance productivity. Due to this intensive management, pasturelands support a much higher stocking density than rangelands. The distinction is based on the degree of human intervention used to produce forage.
Ecological Importance
Grazing lands provide a significant service in the global carbon cycle, acting as substantial carbon sinks by storing atmospheric carbon dioxide below ground in the soil. Unlike forests, where most carbon is stored in visible biomass, up to 90 percent of the carbon in grazing land ecosystems resides in the soil as organic matter. Globally, these systems contain between 10 and 30 percent of the world’s soil carbon reserves, making even slight changes in management consequential to atmospheric carbon levels. This deep storage is relatively stable and represents a long-term mechanism for climate change mitigation.
Soil health is directly supported by the dense, deep root systems characteristic of healthy grassland vegetation. These roots physically bind soil particles, which is highly effective at preventing wind and water erosion, especially compared to tilled cropland. Robust root networks increase soil organic matter, enhancing the soil’s capacity to absorb and hold water. This increased infiltration recharges groundwater and helps to mitigate flood hazards in the surrounding landscape.
Grazing lands are centers of biodiversity, providing habitat for a wide array of plant and animal species, including grassland-specific birds and insects. Moderate grazing often maintains and increases plant diversity by preventing dominant species from taking over. The disturbance from grazing and trampling stimulates plant growth and nutrient cycling, mimicking natural processes that co-evolved with large wild herbivores. Maintaining these intact habitats is a strategy for protecting regional and global species diversity.
Stewardship and Sustainability
Effective stewardship focuses on management practices that prevent land degradation and ensure long-term health and productivity. A central practice is rotational grazing, an adaptive method involving strategically moving livestock through several smaller fenced areas, known as paddocks. This allows previously grazed areas a period of rest and regrowth. This movement mimics the natural migratory patterns of wild herds, giving forage plants sufficient time to recover biomass and rebuild root reserves. Rotational grazing is a significant tool in regenerative agriculture because it improves soil structure, enhances water infiltration, and promotes carbon sequestration.
Monitoring stocking rates is a complementary practice, referring to the number of animals grazing on a specific area over time. Setting an appropriate stocking rate is a significant decision for land health, as excessive stocking leads to overgrazing, depleting plant cover and causing soil compaction. Land managers measure forage availability and adjust animal numbers to ensure the harvest does not exceed the land’s capacity to regenerate. When grazing is properly managed, it improves ecosystem services; when mismanaged, it accelerates erosion and decreases productivity.
Restoration efforts are a necessary component of sustainable management, particularly on lands degraded by past overgrazing or poor land uses. These efforts involve reseeding with native species, controlling invasive plants, and implementing techniques to break up compacted soil. The goal is to reverse degradation and restore the ecological function of the land. This ensures grazing systems remain productive while continuing to provide essential services like clean water and carbon storage.