Rangelands

Rangelands extend over all latitudes, and are usually characterized by low biomass production due to constraints related to soil, temperature and water availability. They cover some 25 percent of the global land area, and include the drylands of Africa (66 percent of the total continental land area) and the Arabian Peninsula, the steppes of Central Asia and the highlands of Latin America (Nori and Neely 2009). Vegetation is mostly dominated by natural plant communities of perennial and annual species, including grasses, shrubs and trees. By their nature, rangelands are fragile ecosystems and when mismanaged readily result in degradation, loss of biodiversity and water retention capacity, carbon emissions and reduced productivity.

The extent and trends in rangelands are hard to assess. Global statistics indicate that the total area of rangelands was 3.43 billion ha in 2000, and decreased slightly to 3.36 billion ha by 2008. The reasons for these minor changes cannot be easily identified, though may include poor data, desertification and encroachment of agriculture. Large-scale conversion of drier grasslands to crops and inappropriate management has had unfortunate consequences, such as the ‗dust bowl‘

of the Great Plains of the USA in the 1920s and 1930s. In the mid-20th century, drylands were widely cultivated in the USSR, but crop production was also unsustainable in that region (Boonman and Mikhalev 2005) and these lands are now reverting to rangelands.

3.2.1 Importance of rangelands

The contribution that rangelands make to the maintenance of ecosystem functions and biodiversity is important. In addition to providing feed for livestock, they play an important role as a habitat for wildlife, for water retention and for the conservation of plant genetic resources.

The flora of rangelands is rich: about 750 genera and 12 000 grass species. These ecosystems are also important for the maintenance of fauna; for example, grasslands contain 11 percent of the world‘s endemic bird areas (White et al. 2000: 40), and contribute to the maintenance of pollinators and other insects that have important regulating functions. Ecosystem benefits, especially regulating services such as water infiltration and purification, climate regulation (e.g.

carbon sequestration) and pollination, have begun to be assigned an economic value, and systematic data-gathering in rangelands of both developed and developing countries should be a global priority.

3.2.2 Challenges facing rangeland and their users

Over 600 million people depend on rangelands for their livelihoods (FAO 2011). Pastoral societies have developed strategies that continuously adapt to limited, highly variable and unpredictable resource endowments (e.g. by migratory livestock rearing), but both the rangelands and their users are also vulnerable to the changes brought by demographic pressure, conversion of cropland and climate change. Fluctuations in rainfall and drought are recurring problems in rangelands – for example, 70 million people in the Horn of Africa, many of whom are pastoralists, suffer from long-term chronic food insecurity (FAO 2000). Table 1: lists major pastoral systems and illustrates how they evolve with time.

Table 1 Regional zonation of pastoral systems

Zone Main Species Status

sub-Saharan Africa Cattle, camel, sheep, goats Declining due to advancing agriculture

Mediterranean Small ruminants Declining due to enclosure and advancing agriculture Near East and

South-Central Asia

Small ruminants Declining in some areas due to enclosure and advancing agriculture

India Cattle, camel, sheep, goats Declining due to advancing agriculture but peri-urban livestock production

expanding

Central Yak, camel, horse,

sheep, goats

Expanding following de-collectivization

Circumpolar Reindeer Expanding following

de-collectivization in Siberia, but under pressure in Scandinavia

North America Sheep, cattle Declining with increased enclosure of land and alternative economic opportunities

Andes Llama, alpaca Contracting llama

production, due to expansion of road systems, and European-model livestock production but expansion of alpaca wool production

Source: Blench (1999)

4.0 Summary

In this unit we have leant that:

i. Forests play a crucial role in the hydrological cycle.

ii. The contribution that rangelands make to the maintenance of ecosystem functions and biodiversity is important.

iii. Net losses of forested land were concentrated in South America, sub-Saharan Africa, Southeast Asia and Oceania.

5.0 Conclusion

Forests influence the amount of water availability, regulate surface and groundwater flows, and ensure high water quality. Fluctuations in rainfall and drought are recurring problems in rangelands – for example, 70 million people in the Horn of Africa, many of whom are pastoralists, suffer from long-term chronic food insecurity.

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6.0 Tutor Marked Assignments

1. Highlight the importance of forests.

2. What are the challenges facing rangeland and their users?

7.0 References and other Resources

Blench, R. (1999). Extensive pastoral livestock systems: issues and options for the future. Rome, FAO. (Available at: http://www.smallstock.info/reference/FAO/

kyokai/document2.pdf)

Boonman, J.G. and Mikhalev, S.S. (2005). The Russian Steppe. In: Suttie, J. M., Reynolds, S. G.

& Batello, C. (eds.) Grasslands of the World. Rome. FAO Plant Production and Protection Series No. 34, 381–416.

Food and Agriculture Organization (2000). The elimination of food insecurity in the Horn of Africa. A strategy for concerted government and UN agency action. Summary report of the inter-agency task force on the UN response to long-term food security, agricultural development and related aspects in the Horn of Africa. Rome. (Available at:

http://www.fao.org/docrep/003/x8530e/x8530e00.htm#TopOfPage)

Food and Agriculture Organization (2008). Scoping agriculture-wetland interactions. FAO Water

Reports 33. Rome, Italy. (Available at:

http://www.fao.org/nr/water/docs/WaterReports33.pdf)FAO (2010). Global forest resources assessment 2010. FAO Forestry Paper 163. Rome, FAO. (Available at:

http://foris.fao.org/static/data/fra2010/FRA2010_Report_en_WEB.pdf)

Food and Agriculture Organization (2011). The state of the world‘s land and water resources for food and agriculture (SOLAW) – Managing systems at risk. Food and Agriculture Organization of the United Nations, Rome and Earthscan, London.

Nori, M. and Neely, C. (2009). The tragedy is on, the tragedy is over: pastoral challenges and opportunities for conservation agriculture. Proceedings of the IV World Congress on Conservation Agriculture, New Delhi, 4–7 February 2009. (Also availableat:http://www.achmonline.org/Resource/Conservation%20Agriculture,%20Nori

%20and%20Neely.pdf)

White, R.P., Murray, S. and Rohweder, M. (2000). Pilot analysis of global ecosystems: grassland ecosystems. Washington, DC, World Resources Institute. (Available at:http://www.wri.org/publication/pilot-analysis-global-ecosystems-grasslandecosystems) UNIT 4: SOCIO-ECONOMIC DEPENDENCY ON LAND RESOURCES

TABLE OF CONTENTS

1.0 Introduction 2.0 Objectives 3.0 Main content

3.1 The links between Poverty, access to Land and Water, and Land Degradation