Grasslands are mostly found in arid and semi-arid zones where rainfall is sparse and unpredictable, or in humid zones where topography is steep or temperatures low. Their existence is also determined by cultural factors, distance to markets or the presence of low fertility or stony soils, salinity or seasonal flooding. In this document, "grasslands" is used from a pastoral resource viewpoint and refers to any extensive areas of grazing, not only natural grasslands but also including shrub lands and forested lands that have a herbaceous or shrubby understorey providing feed for livestock.
Natural grazing is probably the most widespread land-use worldwide; sound statistics are not available, but in developing countries at least, in addition to "permanent pasture," much of the areas listed as forest, wasteland or desert (excepting the most barren and waterless wastes) are grazed at some point in the year. Extensive livestock rearing is the main means of obtaining an economic output - meat, dairy products, fibres - from such land; these production systems are low-input and rely on the natural vegetation, unlike farm-based intensive livestock rearing. They require great mobility and space so that stock can be moved according to availability of feed, as influenced by rainfall or season. In the semi-arid regions of industrialized countries, stock rearing is typically on very large private holdings (ranches in North America) that have sufficient space to allow some buffering against seasonal differences in feed availability. The traditional pastoral sector, however, operates in areas where land title is less well defined and individual herds are usually much smaller than those of ranches; it often relies, therefore, on mobility (including transhumance and nomadism) within land shared by many households, and sometimes several ethnic groups.
Worldwide, there are at least 40 million pastoralists who depend on natural grazing for their livelihood; most are subsistence herders and more than half are in Africa. Rapid increases in human and livestock populations this century have contributed to increasing grazing pressures, particularly in arid and semi-arid environments (Figure 1) (Grandin, 1987; Olsson and Rapp, 1991; Wiggins, 1991). This book addresses those involved in the design and execution of pastoral projects and others dealing with traditional, extensive livestock production. Extensive grazing lands are not only important for livestock; they are often major catchments and wildlife habitats, as well as sites for the in situ conservation of plant genetic resources. Their proper management is, therefore, of great concern to the whole community. It is hoped that this publication will assist in their conservation and sustainable use.
Concurrent with population increase, there is often a decrease in the area and quality of grazing lands due to non-pastoralists colonizing key, high potential land (e.g. IFAD, 1993b). Climatic conditions are also compounding the pressures on grazing land in some areas, and the effect of form of land tenure on grassland condition can be a contributing factor. Increasing demand for animal products, and pressures on land, have forced many grazing-based livestock production systems to become more demand-led, with less consideration for the productive capacity of the pastoral vegetation. As a consequence, the sustainability of use of many grasslands is being questioned. Such issues of sustainability are not confined to the so-called "non-industrialized countries." For example, the grasslands of Australia and New Zealand have undergone major crises of sustainability (Hughes, 1991; O'Connor, 1987; Pressland and Graham, 1989), despite high levels of technical skills and resources for grassland development (including development programmes subsidized by government.). Soil nutrient depletion, which is occurring on some grazing lands, is accelerated by increases in livestock numbers, and has a significant impact on long-term livestock support capacity.
Figure 1. Population pressures on grazing lands - increases in human and livestock populations in Sudan, 1917-1977 (From Olsson and Rapp, 1991)
Since pastoral systems and socio-economic patterns and conditions are intimately linked, a decline in grassland productivity negatively affects family income, health and the distribution of scarce resources (World Bank, 1991).
From a forage resource viewpoint, the net reactions of grazing land to environmental crises are difficult to predict because of the complexity of the ecosystem and its many dynamic interacting links. Some are sensitive to environmental changes, while others appear quite resilient (Skarpe, 1991). Those vulnerable to increased grazing pressure suffer decreases in vegetative cover, accelerated soil erosion, loss of soil fertility and structure, and a reduction in biodiversity.
As a consequence of perceived changes in status or condition of many grazing lands, a wide range of development programmes were initiated by many international agencies. Interventions designed to reverse the trends and increase production included forage species introduction, afforestation, mechanical and physical work on soil and vegetation, burning, fertilization with manure or chemicals, livestock breed and health improvement, the development of fodder crops, and better use of crop residues. Environmental factors limit technical options for grassland and fodder development, especially rainfall. In some humid temperate zones, pasture improvement through the introduction of grasses and legumes and localized intensive growing of fodder crops are options (providing managerial skills are adequate); in contrast, in semi-arid and arid zones, improvement tends to be based on managerial rather than technical interventions.
The results of development activities have often been disappointing, especially in drier environments (Breman et al., 1984; Sandford, 1983). Many attempts have been made to improve the traditional extensive grazing lands of Africa and the Near East; few have succeeded and even fewer have had a positive effect on vegetative cover (FAO, 1992). Failure has been attributed to the misinterpretation of the biophysical environment and technical opportunities, as well as incompatibility with local cultural and socio-economic factors. Furthermore, development programmes proven within grassland systems in "equilibrium" were mistakenly applied to "non-equilibrium" systems.
Grasslands are dynamic ecosystems and therefore are often a changing resource. Short- and long-term shifts in climate affect their productivity and must be accepted as a feature of the system if sustainable use is to be realized. Furthermore, technical solutions cannot be expected to restore system "balance:" population pressures and unrealistic expectations of the productive capacity of the resource must first be addressed.
The disappointing record of development programmes forced a re-interpretation of grassland ecosystems, their dynamics and development opportunities. In the extreme, this has led to a re-evaluation of concepts such as desertification, overgrazing, land degradation and an assessment of whether, in some grazing lands, no form of development is possible. The scientific community now acknowledges that the exploitation of spatial and temporal variability within grazing lands is a key factor for their sustainable use. With traditional, pastoral peoples this has long been appreciated, as transhumant and nomadic systems show. The re-interpretation of grassland ecosystems is often referred to as the "paradigm shift." This shift has led to a revised approach to grassland development, based on a more complete understanding of grazing-based livestock production systems, including their limitations and dynamics, and a greater role for local people in participatory planning. The "new perspective," and the recent availability of innovative data collection and analysis tools, provides powerful new aids to improving the protection and management of grazed environments.
The document describes components of pastoral systems and highlight issues relating to resource endowment and environmental dynamics that should be considered during development planning. It shows an integrated approach to land, forage and livestock resource assessment that facilitates quantification of the resources, understanding of resource component inter-relationships, prediction of environmental impact, estimation of livestock support capacity, and appraisal of development options. The document is intended for project designers, planners and managers, and grassland and livestock technicians. The techniques described have been successfully applied in a number of FAO projects since 1986, and are designed to overcome shortcomings of traditional methods of forage assessment and livestock carrying capacity estimation.
The use of Resource Assessment for Pastoral Systems (RAPS), a computer-based pastoral resource modelling system, is introduced as a tool to integrate and analyse the dynamics and complexity of grassland-livestock production systems so that critical components can be identified, and management and development options evaluated.
The document consists of six chapters, in addition to this introduction:
- Chapter 2 discusses grazing resource management and development, including grassland condition, dynamics and implications for sustainable development.
- Chapter 3 relates to the scope and type of information required for grassland and livestock resource assessments. This includes sources of information, socio-economic conditions, government policy, services and infrastructure, general descriptions of the development or project areas and the identification and classification of land units and forage resource groups. Forage resource production information covers production and utilization, along with grassland condition and dynamics. Livestock statistics, other uses of grazing land, data quality issues and a brief description of tools that may be used for information recording and data analysis are presented.
- Chapter 4 deals directly with components of grassland and resource use and development assessment. The first section relates to the impact of current use of grasslands on the pastoral resources and environment. This is followed by development potential assessment. Finally the design and implementation of environmentally sustainable management systems is discussed.
- Chapter 5 describes the modelling system RAPS, which is used to assess the grazing and livestock resources of pastoral systems.
- Chapter 6 presents four case studies to illustrate the application of the techniques described in the previous chapters. All case studies demonstrate the use of pastoral resource modelling.
- Chapter 7 presents comment relating to the case studies and summarizes the approach, procedures and application of the techniques described in the book.
Case studies are drawn from FAO project inputs carried out in China (FAO 1997), Sudan (FAO 1994a), Ethiopia (FAO 1989) and Bhutan (FAO 1987) between 1987 and 1997. Each case study is essentially a summary of the original technical report relating to grazing resource assessment and livestock production, and presents the objectives of the project component, methods used, and examples of results and recommendations. The general stages and components of development planning based on pastoral resource assessment are illustrated in Figure 2.
The issues, components and methods presented in the document should not be interpreted as limits to, but as the basis of, or framework for, assessment. Furthermore it is accepted that the complete range and detail of data outlined in the document will rarely be available in entirety for a particular project area. The scope and detail is merely presented as a compendium of resource parameters, options and indicators to assist the analysis of the grassland system and evaluate development options. In practice, the resource assessment should incorporate any unique circumstances or interpretations of a particular pastoral system and use as many convergent indicators as practicable.
