Rangelands can be defined as “land on which the indigenous vegetation…is predominantly grasses, grass-like plants, forbs or shrubs that are grazed or have the potential to be grazed, and which is used as a natural ecosystem for the production of grazing livestock and wildlife”. Though this definition highlights the “naturalness” of rangelands, people strongly influence rangelands in terms of management practices and tools such as livestock stocking rates, management of vegetation and use of fire. As such, rangelands depend on the interaction of the physical environment (vegetation, soils, water etc.), with both livestock and people.
Rangelands can include annual and perennial grasslands, shrub and dry woodlands, savanna, tundra, and desert. Rangelands can include natural grassland, tall grass prairies, desert shrublands, shrub woodlands, savannas, wetlands, chaparrals, deserts, tundras, taiga, and certain forb and shrub communities. Temperate and tropical forests that are used for grazing as well as timber production can also be considered to be part of rangelands.
Rangelands are usually found in drylands or arid and semi-arid lands, where rainfall is low and variable resulting in the distribution of vegetation and other resources in an uneven and patchy manner. However not all rangelands are found in drylands (as indeed not all drylands are rangelands), and rangelands can include wetlands and forests too.
Rangelands occupy around 47%of the world’s surface in wet or dry, and hot or cold climates . Rangelands harbour 35% of global biodiversity hotspots, and provide habitat for 28% of endangered species . They also store 30% of terrestrial carbon and have the potential to store 197 million tons of CO2 from the atmosphere per year for 30 years and when saturation is achieved they could off-set 3.3% COs emission in the U.S. from fossil fuel . Grazing lands sequester between 200-500kg of carbon per hectare per year, playing a leading role in climate change mitigation .
The map below shows barren land (orange), grassland (green), shrubland (turquoise), tundra-alpine (blue), and woodland-savanna (pink).
This map of rangelands of the world is a joint project of the Information & Education (I&E) and Remote Sensing & GIS committees of the Society for Range Management (SRM). The project was conducted by two professors from the Rangeland Ecology and Management Department at the University of Idaho, Karen Launchbaugh and Eva Strand, with input from the SRM I&E committee. The map shows major forms of plant growth, assigning eco-regions to the following rangeland categories: Desert; Grassland; Shrubland; Woodland and Savanna; and Tundra - University of Idaho http://www.webpages.uidaho.edu/what-is-range/rangelands_map.htm
At another level, the term “rangeland” can be used to describe the management unit of pastoralists and/or other land users. For pastoralists, the rangeland unit will include both dry and wet season grazing, water points and such as salt-licks (for cattle). Pastoralists have an intricate understanding of their rangeland unit. An example of a map of a rangelands unit drawn on the ground by pastoralists in Tanzania is shown here.
Maasai pastoralists mapping out their rangeland unit in Tanzania (Credit: Fiona Flintan)
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