The Improvement of Tropical and Subtropical Rangelands (BOSTID) Part I Introduction (introduction...) References The nature of tropical and subtropical rangelands (introduction...) Range classification Social system-ecosystem interactions References The social context for rangeland improvement (introduction...) Production systems in tropical and subtropical regions Context of environmental degradation References The economic context (introduction...) Range systems The basis of range economics Project analysis Determining costs and benefits Resource evaluation Market price determination References Regional resource assessment (introduction...) Information needs Information acquisition References Site evaluation (introduction...) An ecosystem perspective A systems approach to site evaluation Evaluation of abiotic and biotic components Integrated evaluations References Grazing management (introduction...) Grazing management concepts Time of grazing Distribution of grazing Type of animal grazing Number of animals grazing Grazing management planning Grazing management systems Livestock management The herima system in Mali References Rehabilitation techniques Establishing plants on the range Natural revegetation Direct seeding Improvement of tropical and subtropical rangelands Selected practices References Criteria for plant selection Project planning Socioeconomic and management considerations in feasibility studies Adaptation to ecoclimatic conditions Adaptation to soils Adaptation to physiography, geomorphology, topography, slope, and aspect Ability of introduced species to compete with native vegetation Use regimes Availability of seeds and plant materials Maintenance of biological diversity Plant improvement References

The Improvement of Tropical and Subtropical Rangelands (BOSTID)

Part I

Introduction

In this report, rangelands are defined as "land carrying natural or semi-natural vegetation which provides a habitat suitable for herds of wild or domestic ungulates" (Pratt, Greenway, and Gwynne, 1966). Rangelands typically possess characteristics that make them unsuitable for agriculture or intensive forestry: they are variously too dry, too steep, too rocky, poorly drained, or too remote. In Africa, the Near East, and southern Asia - the geographical focus of this report - rangelands occupy 2,666 million hectares, or 53 percent of the land surface (table 1).

In the areas considered, there are two general systems of rangeland utilization: systems that use the land to produce goods that are removed or exported from the land (ranches), and those that chiefly provide subsistence for people associated with livestock and wildlife populations (indigenous pastoral systems). Contrary to popular belief in industrial nations, pastoral systems are not necessarily less productive than ranching systems. African pastoral systems, for example, are often as productive as market-oriented ranching systems in comparable areas in terms of protein produced per unit of land utilized.

Table 1 Distribution of the World's Pastures and Rangelands, 1955-83

Most ranches are privately owned, and characteristically use investments of capital and various management techniques on large areas of land to increase livestock production. Unlike pastoral systems, labor inputs are low. Hence, ranching often produces more protein per hour of labor than does pastoralism. On the other hand, ranching requires vastly greater inputs of energy, and expenses incurred in connection with fencing, water development, brush control, revegetation, grazing management, and selective breeding are substantial.

Pastoral systems represent the principal form of rangeland utilization in Africa and Asia. They involve significant social adaptations to the movement of livestock or wildlife from one location to another in relation to the availability of forage and water. The rangelands utilized are seldom privately owned, and mechanical and chemical inputs are seldom prominent. The systems are labor intensive. It has been estimated that livestock and wildlife support some 30-40 million pastoralists, and the animals and animal products associated with pastoral systems are critical to millions of other individuals in settled communities (International Institute for Environment and Development and the World Resources Institute, 1987).

The importance of livestock in pastoral systems exceeds their value as sources of milk, meat, blood, and hides. Livestock often represent a means of accumulating capital and, in some societies, are associated with social status. They are assets that can reproduce and that can be liquidated should cash be required. In addition to supporting livestock, rangelands serve as sources of other significant economic products: bushmeat, fruits, berries, nuts, leaves, flowers, tubers, and other food for human populations, as well as medicinal plants, building materials, thatch, fencing, gums, tannin, incense, and other products important to the economies of rural populations (Sale, 1981; National Research Council, 1983; Malhotra, Khomne, and Gadgil, 1983).

The importance of rangelands as sources of bushmeat and vegetable foods for human populations deserves special attention. These foods are derived from species that are well adapted to the environmental peculiarities of the regions in which they are found. Hence, such foods are often available in the event of crop failure or substantial losses of livestock. Even during periods with average rainfall, satisfactory crop yields, and herd stability, such foods constituted a significant part of local diets. Indeed, in many societies, the offtake of wildlife from rangelands exceeds that of livestock in importance. In 1959, for example, the sedentary and pastoral peoples of the Senegal River Valley in West Africa relied upon fish and wildlife for over 85 percent of the meat that they consumed (Cremoux, 1963); native plants were of equal or greater importance. Since that time, widespread environmental degradation has dramatically reduced the availability of the natural products associated with local coping strategies and has correspondingly increased the vulnerability of rural populations (National Research Council, 1983). In most instances, the degradation is a result of breakdowns in the traditional resource management systems that for centuries had maintained an equilibrium between environmental systems and human activity (National Research Council, 1986).

TABLE 2 Cattle Populations in the West African Sahel

TABLE 2 Cattle Populations in the West African Sahel

Number of Cattle (in thousands)
Country	1940	1968-1970	1974	1978	1982	1985
Senegal	440	2,615	2,318	2,500	2,300	2,200
Mauritania	850	2,100	1,175	1,200	1,500	1,350
Mali	1,174	5,300	3,640	3,800	5,300	5,800
Burkina	491	2,900	2,300	2,600	2,871	2,800
Niger	754	4,200	2,200	2,850	3,487	3,530
Total	3,709	17,115	11,633	12,950	15,458	15,680

SOURCES: Gallais, 1979; Africa South of the Sahara 1986 1985; and Africa

South of the Sahara 1988 1987.

Rangeland ecosystems, particularly those in arid and semiarid regions, are highly susceptible to degradation. In many regions, degradation is chiefly a result of changing herd composition and overstocking. Particularly noteworthy since the advent of the colonial period has been a proportional shift in herd inventories favoring cattle, a form of livestock poorly adapted to dryland ecosystems, at the expense of well-adapted and less environmentally destructive forms, such as camels, as the former were more marketable within the context of the new economic order (Chassey, 1978). In the West African Sahel, for example, colonial policy resulted in an almost fivefold increase in cattle populations between 1940 and 1968 (table 2).

Agricultural expansion has also contributed to the degradation of tropical and subtropical rangelands. In drylands, agricultural expansion results in increased pressure on rangelands because the conversion of the more productive forage reserves to crop land forces pastoralists to "overgraze" the remaining land base (Thomas, 1980).

Moreover, grain crops deplete soil nutrients at a rate thirty times greater than the rate of nutrient loss in a properly stocked range ecosystem (Heady, 1975). The cost of replacing the lost phosphorus, potassium, nitrogen, and other nutrients is generally prohibitive.

In many regions, high levels of sustained use pressure have eliminated the more palatable plant species (species referred to as "decreasers" in range science). In dryland ecosystems, plant growth is relatively slow. When aerial biomass is consumed by foraging livestock, many plants respond by transferring nutrients from their roots in order to produce new leaves. This results in reduced rooting. Reduced rooting, in turn, reduces the ability of the plant to absorb moisture and nutrients even during rains. As the more palatable species are weakened, less palatable species ("increasers") become dominant. With continuing high levels of use pressure, increasers give way to undesirable shrubs, grasses, and forbs ("invaders"). As these species are overgrazed, the land surface is exposed to further, more severe, degradation. In the drylands of Africa and Asia, cattle have been particularly destructive. Unlike camels and goats and most native herbivores, which are predominantly browsers, cattle are grazers. Cattle therefore increase pressure upon perennial grasses and often eliminate them, causing ecological deflections toward ephemeral annual grasses and relatively unproductive trees and shrubs, such as Calotropis procera (Gaston and Dulieu, 1976).

The reduction or elimination of vegetative cover, in combination with trampling and the compaction of the surface by livestock, reduces infiltration and permits the mobilization of soil particles subject to transport by overland flow. This results in depressed groundwater tables and increased soil erosion. Surface exposure and the reduced organic content of soils also result in altered soil-water relationships and greater amplitude in soil temperatures. This altered soil ecology adversely affects important soil microorganisms, such as the rhizobial bacteria responsible for nitrogen fixation in acacias and other leguminous genera. This, in turn, affects nutrient regimes and results in a further loss of soil structure. Altered soil ecology directly eliminates additional plant species and frustrates regenerative processes in others. Further losses occur through disruptions in various biological dependency and affinity relationships. Environmental degradation both reduces range carrying capacity for livestock and affects wildlife populations through habitat modification. Rangeland conditions in selected countries of Africa, Asia, and Western Asia are described in tables 3, 4, and 5.

Table 3 Rangelands Conditions in Selected African Countries

Table 3 Rangelands Conditions in Selected African Countries - continue 1

Table 3 Rangelands Conditions in Selected African Countries - continue 2

Table 3 Rangelands Conditions in Selected African Countries - continue 3

Table 4 Rangeland Conditions in Selected Western Asian Countries

Table 4 Rangeland Conditions in Selected Western Asian Countries - continue 1

Table 4 Rangeland Conditions in Selected Western Asian Countries - continue 2

Table 4 Rangeland Conditions in Selected Western Asian Countries - continue 3

Table 5 Rangeland conditions in selected Asian countries

Table 5 Rangeland conditions in selected Asian countries - continue 1

The effects of rangeland degradation often extend well beyond the rangelands themselves. Dust originating in degraded rangelands is transported by dry-season winds to distant areas, causing annoyance, health hazards, and costly interruptions in air and ground traffic. The rapid release of runoff in degraded rangelands following rains contributes greatly to destructive flooding in downstream lowlands, and sediment entering drainage systems in degraded rangelands shortens the useful life of reservoirs and irrigation systems.

Less obvious effects would include the impact of rangeland devegetation on climatic regimes. For example, it is now widely believed that precipitation is strongly influenced by biogeophysical feedback mechanisms (Charney, 1975). According to this hypothesis, drought is reinforced through changes in vegetative cover. Large-scale losses of vegetation would increase surface albedo, which, in turn, would affect the atmospheric energy budget in such a way that the subsidence, which promotes aridity, would be intensified.

Further, it is now believed that levels of precipitation are strongly influenced by soil moisture locally released into the atmosphere through evapotranspiration. Hence, reduced vegetative cover and decreased soil moisture would result in reduced local precipitation. Finally, losses of vegetation affect surface roughness in the atmospheric boundary layer. Surface roughness contributes to the destabilization of moisture-laden air masses, thus encouraging precipitation. Devegetation also reduces carbon dioxide uptake in the planetary biomass. The greater concentration of carbon dioxide in the atmosphere contributes to global warming, causing changes in atmospheric circulation and rising sea levels through the melting of continental ice sheets (Study of Man's Impact on Climate, 1971; Woodwell, 1984).

The science of range management originated in North America, and North American approaches to range management are described in several wellknown volumes, such as A. W. Sampson (1952), Stoddart and Smith (1955), R. R. Humphrey (1962), and National Research Council (1962, 1984). Historically, attempts to transfer experience gained in the management of North American or Europe an rangelands to the management of tropical and subtropical rangelands have been unsuccessful (Heady and Heady, 1982). In improving tropical and subtropical rangelands, it is important to carefully characterize the physical system being managed in order to better understand the biological potential of the system and assure that critical ecological processes are restored and maintained. It is equally important to relate efforts in range improvement to the needs,

knowledge, adaptations, and capabilities of local populations, as well as to the broader economic and political contexts of such efforts. The widespread belief that pastoral systems are simply artifacts of the past requires reexamination. The view that range improvement in the tropics and subtropics should focus narrowly upon the increased per unit productivity of selected forms of livestock, usually cattle, at the expense of the biological diversity basic to the maintenance of local coping strategies and economies should similarly be reexamined. This report describes tropical and subtropical rangelands, addresses issues of socioeconomic context, discusses approaches to regional assessment and site evaluation, explores management strategies, and provides criteria for plant selection in relation to efforts in range improvement. The case studies appended to the report provide further information regarding these issues. The Improvement of Tropical and Subtropical Rangelands is the third report to appear in the series, "Resource Management for Arid and Semiarid Regions." Other titles include Environmental Change in the West African Sahel (1983) and Agroforestry in the West African Sahel (1983).

References

Africa South of the Sahara 1986. 1985. 15th ed. Europa Publications, London, England.

Africa South of the Sahara 1988. 1987. 17th ed. Europa Publications, London, England.

Charney, J. G. 1975. Dynamics of Deserts and Drought in the Sahel. Quarterly Journal of the Royal Meteorological Society 101(428): 193202.

Chassey, F. de. 1978. La Mauritanic - 1900-1975. Editions Anthropos, Paris, France.

Cremoux, P. 1963. The importance of game-mest consumption in the diet of sedentary and nomadic peoples of the Senegal River Valley. Pp. 127129 in Conservation of Nature and Natural Resources in Modern African States. IUCN Publications New Series, no. 1. International Union {or the Conservation of Nature and Natural Resources, Morges, Switzerland.

Gallais, J. 1979. La situation de l'levage bovin et le problme des leveurs en Afrique occidentale et centrale. Les Cahiera d'Outre-Mer 32(126):113-138.

Gaston, A. and D. Dulieu. 1976. Pturages du Kanem. Institut d'levage et de Mdecine Vtrinaire des Pays Tropicaux, Maisone-Alfort, France.

Heady, H. F. 1975. Rangeland Management. McGraw-Hill, New York, New York, USA.

Heady, H. F. and E. B. Heady. 1982. Range and Wildlife Management in the Tropics Longman, London, England.

Humphrey, R. R. 1962. Range Ecology. Ronald Press, New York, New York, USA.

International Institute for Environment and Development and the World Resources Institute. 1987. World Resources 1987. Basic Books, New York, New York, USA.

Malhotra, K. C., S. B. Khomne, and M. Gadgil. 1983. Hunting Strategies among Three Non-Pastoral Nomadic Groups of Maharashtra. Man in India 63(1):23-39.

National Research Council. 1962. Range Research: Basic Problems and Techniques. Joint Committee of the American Society of Range Management and the Agricultural Board of the National Academy of Sciences. National Academy of Sciences-National Research Council, Washington, D.C., USA.

National Research Council. 1983. Environmental Change in the West African Sahel. Board on Science and Technology for International Development. National Academy Press, Washington, D.C., USA.

National Research Council. 1984. Developing Strategies for Rangeland Management. Board on Agriculture and Renewable Resources. Westview Press, Boulder, Colorado, USA.

National Research Council. 1986. Proceedings of the Conference on Common Property Resource Management. Board on Science and Technology for International Development. National Academy Press, Washington, D.C., USA.

Pratt, D. J., P. J. Greenway, and M. D. Gwynne. 1966. A classification of East African rangeland, with an appendix on terminology. Journal of Applied Ecology 3:369-382.

Sale, J. B. 1981. The Importance and Values of Wild Plants and Animals in Africa. International Union for Conservation of Nature and Natural Resources, Gland, Switzerland.

Sampson, A. W. 1952. Range Management Principles and Practices. John Wiley and Sons, New York, New York, USA.

Stoddart, L. A. and A. D. Smith. 1955. Range Management. 2nd ed. McGraw-Hill, New York, New York, USA.

Study of Man's Impact on Climate. 1971. Inadvertent Climate Modification. MIT Press, Cambridge, Massachusetts, USA.

Thomas, G. W. 1980. The Sahelian/Sudanian Zones of Africa. Profile of a Fragile Environment Report to the Rockefeller Foundation. Rockefeller Foundation, New York, New York, USA.

Woodwell, G. M., ed. 1984. The Role of Terrestrial Vegetation in the Global Carbon Cycle. SCOPE 23. John Wiley and Sons, Chichester, England.

World Resources Institute and the International Institute for Environment and Development. 1986. World Resources 1986. Basic Books, New York, New York, USA.

World Resources Institute and the International Institute for Environment and Development. 1988. World Resources 1988-89. Basic Books, New York, New York, USA.

The nature of tropical and subtropical rangelands

This report focuses on areas of low and undependable precipitation within the tropics and subtropics. (1) Much of the area is occupied by savannahs and thorn-bushlands, often characterized by a rich diversity of grasses. The prominence of grasses in tropical rangelands in many instances reflects the repeated use of fire in hunting or range renewal (Sauer, 1952), as well as the coevolution of grasses and wild herbivores (Harris, 1969). Substantial tracts of forest are associated with tropical rangelands in some regions; in others, extensive swamps created by the seasonal overbank flooding of exotic rivers are features of considerable regional importance.

Tropical rangelands differ greatly from rangelands in temperate regions, and social adaptations to these differences are reflected in the management of range resources. Differences of climate (Trewartha, 1954), soils (Sanchez, 1975), vegetation (Davy, 1938; French, 1957), and other environmental factors are well documented and generally well understood. The management of tropical rangelands is further affected by the prevalence of livestock diseases. Rinderpest, foot-and-mouth disease, contagious bovine pleuro-pneumonia, anthrax, east-coast fever, trypanosomiasis, and sheep pox have historically taken heavy tolls in the tropics (Pratt and Gwynne, 1977). Strategies to blunt the impact of disease include increasing livestock holdings to levels that assure the survival of a breeding nucleus. The relatively high levels of social, economic, and political differentiation within the tropics similarly affect the exploitation and management of range resources.

Range classification

Range management issues are usefully considered within the context of ecoclimatic zones. In this report, these zones are defined largely on the basis of land potential and moisture availability (Pratt and Gwynne, 1977). Within the tropics, five such zones can be distinguished:

1. Humid to dry subhumid (moisture index not less than -10).(2) This zone is characterized by forest and derived grasslands and bushlands, with or without natural glades. The grestest potential is for forestry (perhaps combined with wildlife and tourism), or intensive agriculture. The natural grasslands of this zone require intensive management for optimum production. Approximately 0.8 hectare is required per livestock unit, depending upon the related grassland association. (3) In this zone, approximately 2.5 livestock units are required to support one subsistence pastoralist; hence, 2 hectares are required to support each individual. The maximum population density per km² is about 50 pastoralists (see table 1-1).
2. Dry subhumid to semiarid (moisture index -10 to -80). The vegetation of this zone includes moist woodland, bushland, and savanna. Forestry potential is low. However, the agricultural potential is relatively high, soils and topography permitting, with emphasis on lea farming. Large areas are generally under range use and, with intensive management, can carry 1 livestock unit per 1.6 hectares. Approximately 3 livestock units are required to support 1 subsistence pastoralist. Thus, 4.8 hectares are required to support 1 individual. The maximum density of pastoralists would be approximately 21 per km². Regular burning is an important management tool in this zone.
3. Semiarid (moisture index -30 to -42). These are areas with marginal agricultural potential, which in some regions is limited to rapidly maturing grains. The natural vegetation is characteristically dry woodland and savanna. This is potentially productive rangeland. Approximately 3.5 hectares are required per livestock unit, except where dry seasons exceed 6 months. The corresponding human carrying capability is 7 individuals per km². Animal husbandry is limited principally by the encroachment of woody vegetation and, in some locations, by leached soils. In many areas, particularly in Africa, the more open country with a high density of wildlife is a valuable tourist attraction.

TABLE 1-1 Relationship between Ecological Zone, Livestock Carrying Capacity, and Maximum Population Density under Subsistence Pastoralism

TABLE 1-1 Relationship between Ecological Zone, Livestock Carrying Capacity, and Maximum Population Density under Subsistence Pastoralism

	Ecoclimatic Zones
	1	2	3	4	6
Hectares required per livestock unit	0.8	1.6	4.0	12.0	42.0
Livestock units required to support one head of population	2.6	3.0	3.6	4.0	4.6
Hectares required per head of population	2.0	4.0	14.8	48.0	189.0
Maximum population density per km²a	60.0	21.0	7.0	2.0	0.6

^a These figures presume that all land is accessible and productive; if actual population density under subsistence pastoralism even approaches these estimates, overpopulation is indicated. Higher population can only be sustained if the pastoralists derive a substantial part of their subsistence from vegetable foods--collected, grown, or procured in exchange for livestock.

SOURCE: Modified after Pratt, 1968.

4. Arid (moisture index -42 to -51). This zone is suitable for agriculture only where fertile soils coincide with a favorable distribution of precipitation, or where rainwater is concentrated in depressions. Many arid rangelands are dominated by species of Acacia or Prosopis. Perennial grasses, such as Cenchrus ciliaris, can be prominent, but succumb quickly to inadequate management. As many as 12 hectares may be required per livestock unit. Wildlife is important, particularly where dry thorn-bushland predominates. Burning requires caution but can be highly effective in range manipulation. Approximately 4 livestock units are required to support 1 subsistence pastoralist, and the maximum population density per km² is 2 individuals.
5. Very arid (moisture index -51 to -57). This zone supports rangeland with relatively low potential. The characteristic vegetation is shrub or grass steppe, with trees largely confined to water courses and seasonally inundated depressions. Perennial grasses, once dominant in many areas, are now localized within a predominantly annual grassland. Growth is confined largely to the seasonal flushes characteristic of summer therophyte vegetative communities, and grazing systems are generally based on pastoralism. Populations of both wild and domesticated animals are restricted by temperature, forage, and available moisture (Schmidt-Nielsen, 1964).

Systems of range classification should be regionally adjusted to include descriptions of the existing vegetation in physiognomic terms, with subdivisions by species composition.

Social system-ecosystem interactions

Most environmental systems are highly modified by human activity. Hence, an understanding of the biological and use potential of these systems benefits greatly from analyses of environmental change over time (National Research Council, 1981). Such analysis is also important in defining ecosystems and in identifying cause-effect relationships that have contributed to changes in the composition and productivity of these systems.

Indigenous social systems, through selection and adaptation, are functionally associated with local ecosystems through flows of energy, material, and information (4) (Rambo and Sajise, 1984). Changes in either the social or environmental system result in changes in the other. Hence, each system must be thoroughly understood if positive change is to be realized. In many, perhaps most, instances, highly disruptive changes are responses to external stimuli. Many examples could be cited. For example, the highly regulated land-use systems of many societies (see the discussion of the hema system in case study 9, Part II) were commonly transformed into open-access systems through the imposition of European public-domain law often combined with land expropriation, a situation that, in many regions, has led to intense use pressure and severe environmental degradation. Similarly, colonial era introductions of cattle into inappropriate areas (such as Zone 5 of the above classificatory system) has led to severe degradation and zonal compression (National Research Council, 1983b). The fixing of boundaries, at national and sub-national levels, has reduced or eliminated strategies of mobility that are crucial to these areas. In addition, increasing market integration has converted highly conservative systems of land use into opportunistic systems that impose greater pressure on available resources. In some cases, this has destroyed the subsistence base that supported the coping strategies of local populations, and has reduced the range of economic options available to them. Wildlife, honey and beeswax, gums and resins, cordage, tannin, and medicinals are among the economic products lost through the de gradation of environmental systems in Africa and Asia.

Characteristically more subtle, but equally important, impacts on socioeconomic and environmental systems result from destructive modifications of indigenous systems of values, ideology, knowledge, and social organization. An unfortunate consequence of past efforts in international development is that so much attention was directed toward the transformation of what are now belatedly recognized to be critically important social adaptations, without corresponding effort being made to understand the context or consequences of the changes promoted.

In addressing issues of range management in the tropics and subtropics, many of the most important clues as to appropriate actions for governments and development agencies reside in the analysis of traditional adaptations to local environmental systems. Growing awareness of the importance of traditional adaptations is contributing to a shift of emphasis by governments and development agencies from open-field cultivation and plantation forestry to more biologically complex agroforestry or agro-sylvo-pastoral systems (National Research Council, 1983a). The growing interest in camel husbandry in the drylands of Africa and Asia similarly reflects pre-colonial strategies of rangeland utilization. In West Africa, for example, camel-based livestock systems were commonly replaced by cattlebased systems by colonial administrators unfamiliar with the characteristics of the drylands of West Africa in relation to the requirements of cattle. By so doing, these administrators contributed greatly to the current environ mental emergency in Africa ( National Research Council, 1983a). An overview of selected African and Asian pastoral adaptations is contained in Douglas Johnson's The Nature of Nomadism (1969).

NOTES

1. In this report, the terms "tropics" and “tropical” are expanded to include the subtropics (Tropical and Subtropical Steppe, Tropical and Subtropical Desert, Mediterranean or Dry Summer Subtropical, and Humid Subtropical climatic regions) as well.
2. Moisture indexes provide expressions of climate derived from monthly rainfafl and evaporation, with the estimate of evaporation based upon measures of radiation, temperature, saturation deficit, and wind speed, weighted for altitude and latitude. They are calculated on the basis of Thornthwaite's concept of moisture indexes (1948), combined with Penman's estimate of evaporation (1948) .
3. In many areas of the tropics, a livestock unit is taken to be a mature zebu cow with calf at Soot (averaging about 300 kg liveweight and having a daily dry matter requirement of 6.5 to 8.5 kg).
4. In an ecological context, information is simply organized or patterned energy or material that tells the observer something about the past, present, or probable future state of an ecosystem or its components. Human response to environmental information is unique compared with that of other organisms because it occurs largely at the cognitive level where cultural conditioning affects both perception and the selection of appropriate responses.

References

Davy, J. B. 1938. The classification of tropical woody vegetation types. Papers of the Commonwealth Forestry Institute 13:1-85.

French, M. H. 1957. Nutritional value of tropical grasses and fodders. Herbal Abstracts 27:1-9.

Harris, D. R. 1969. Agricultural systems, ecosystems and the origins of agriculture. In The Dome&tication and Exploitation of Plants and Animals. P. J. Ucko and G. W. Dimbleby, eds. Aldine-Atherton, Chicago, Illinois, USA.

Johnson, D. L. 1969. THe Nature of Nomadism: A Comparative Study of Pastoral Migrations in Southwestern Asia and Northern Africa.

Department of Geography Research Paper No. 118, University of Chicago, Chicago, Illinois, USA.

National Research Council. 1981. Environmental Degradation in Mauritania. Board on Science and Technology for International Development. National Academy Press, Washington D.C., USA.

National Research Council. 1983a. Agroforestry in the West African Sahel Board on Science and Technology for International Development. National Academy Press, Washington D.C., USA.

National Research Council. 1983b. Environmental Change in the West African Sahel. National Academy Press, Washington D.C., USA.

Penman, H. L. 1948. Natural evaporation from open water, bare soil and grass. Proceedings of the Royal Society. Series A, 193:120-145.

Pratt, D. J. 1968. Rangeland development in Kenya. Annals of Arid Zone 7:177208.

Pratt, D. J. and M. D. Gwynne, eds. 1977. Rangeland Management and Ecology in East Africa Hodder and Stoughton, London, England.

Rambo, A. T. and P. E. Sajise. 1984. An Introduction to Human Ecology Research on Agricultural Systems in Southeast Asia. University of the Philippines at Los Banos, College, Laguna, Philippines.

Sanchez, P. A. 1975. Properties and Management of Soils in the Tropics. John Wiley and Sons, New York, New York, USA.

Sauer, C. 0.1952. Agricultural Origins and Dispersals. Bowman Memorial Lectures, ser. 2. American Geographical Society, New York, New York, USA.

Schmidt-Nielsen, K. 1964. Desert Animals: Physiological Problems of Heat and Water. Oxford University Press, Oxford, England.

Thornthwaite, C. W. 1948. An approach toward a rational classification of climate. Geographical Review 38:55-94.

Trewartha, G. T. 1954. An Introduction to Climate. 3rd Ed. McGrawHill, New York, New York, USA.

The social context for rangeland improvement

The loss of desirable vegetative cover is a threat to world food supplies, to the quality of human life, and to the environment. Desertification, erosion, and the loss of useful plant species can be arrested through revegetation. However, revegetation efforts have often ended in failure or have had limited impact. This has been particularly true in semiarid and marginal lands where the reestablishment of plants is a delicate process.

Revegetation often is required to correct the abuse of existing resources by people and their livestock. More often than not, the success or failure of revegetation schemes is also determined by human activities. Normally, adequate protection of an area is possible only if the people who use the land alter their behavior. If they are unwilling or unable to do so, revegetation efforts become more expensive or even impossible. Far too often, planners and conservationists ignore the human ecology of an area and fail to appreciate the importance of project lands for the survival of human populations. This chapter outlines the relationship between human activity and vegetative change.

In most instances, environmental degradation is a product of human activity. In the regions of Africa and Asia that are the focus of this study, overgrazing, the excessive cutting of fuelwood, and the cultivation of fragile lands - abuses often precipitated by the openaccess provisions of colonial public-domain law and subsequent lack of governmental management and control and economic differentiation associated with commercialization - have led to a loss of plant cover and required the development of government revegetation programs. To fully appreciate why this has occurred and how this process can be reversed, we must first understand how human beings have adapted to specific environmental settings.

Production systems in tropical and subtropical regions

The lands considered here are those in which permanent, sustainable crop production is not possible because of soil and climatic conditions. These regions have, however, supported substantial human populations for thousands of years. In these areas, people have developed production systems adapted to the low and variable productivity of these lands. In semiarid regions and marginal areas, one can find many kinds of production systems - hunting and gathering, agricultural, pastoral, and agro-pastoral systems. Pastoralism and agro-pastoralism are probably the most common production systems in these regions; this is because domestic animals can convert vegetation on land unsuitable for agriculture into food and fiber. In Asia and Africa, agro-pastoral and pastoral societies take many forms. The exact organization of these production systems is influenced by local environmental factors, by history, by culture, by economic considerations, and by level of technology. In addition to these differences, there are similarities that must be understood if successful revegetation is to take place. Traditionally, people who live in semiarid and marginal lands have relied on two strategies - diversification and mobility - to cope with the erratic and generally low productivity of their lands. Mobility is perhaps the most important characteristic of these production systems. By moving about, one can take advantage of the spatial and seasonal variation of plant production. In crop production, systems of shifting and opportunistic cultivation are examples of strategies based on mobility. Land is cultivated for several years, and then it is abandoned to fallow and new land is cleared. The shifting nature of cultivation permitted natural revegetation processes to occur - provided that the fallow cycle was long enough.

Livestock are particularly mobile. Not only can they move about to "harvest" sparse vegetation, but they convert grasses and shrubs into useful products. They also can harvest perennial shrubs and plants that are less susceptible to annual variations in weather than are annual food crops.

Livestock herds in semiarid and marginal regions are rarely confined to the same pastures year-round. Seasonal movement is a common feature of livestock production even among sedentary groups (figure 2-1). A noteworthy difference between agro-pastoralists and pastoralists is that the former do not often move as complete families with their herds, whereas family members often accompany herds among pastoralists. The movement of animals may be as little as a few kilometers or as much as hundreds of kilometers. Movement, however, permits herds to take advantage of seasonally rich pastures, helps to adjust to spatial variances in precipitation, and reduces the stress that is placed on vegetation through constant grazing and trampling (Wagner, 1983).

Mobility is probably the key production strategy for pastoral nomads. Strategies of mobility, such as nomadism and transhumance, are particularly prevalent in areas where the pattern of rainstorms is such that there can be wide differences between the amount of rain received by two plots a few kilometers apart (Gilles and Jamtgaard, 1981). Nomadism serves to reduce environmental stress and personal risk, but it is also more productive than settled livestock husbandry. In eastern Africa, in areas of Masai pastoralism, the grazing capacity of the land is increased 50 percent because of herd mobility (Western, 1982). In the important livestock-producing areas of Africa, comparisons of the productivity of mobile and sedentary herds have indicated the superiority of mobility. In Sudan, Haaland (1977) noted substantially higher mortality rates among sedentary herds than among mobile ones. Breman and de Wit (1983) studied the migratory system based in the Inland Delta of the Niger River in Mali, and found that its productivity often exceeds that of Australian and North American ranches.

Other studies in West Africa have indicated that a disproportionate number of sedentary cattle were lost in the 1968-1974 Sahelian drought. Losses of herds that quickly moved into rainier regions in response to the drought were minimal (Gallais, 1977; Sall, 1978). Not only were the impacts of drought less severe on mobile herds, but migrating herds caused less environmental degradation. Loss of vegetation around boreholes where herds permanently congregated was so severe that it could be easily recognized from satellite photos. Mobility is an important aspect of production systems in semiarid and marginal areas.

Mobility is just one way to cope with a harsh environment. Diversification of subsistence activities is another. For farmers, the ownership of livestock is one diversification strategy. Animals may survive even when grain yields are quite low, so livestock may represent a store of capital that can be used in years of drought. Farmers may also grow a number of different crops to reduce the risk of crop failure. Wheat and barley or maize and sorghum may be grown together because one species tolerates drought better than another. Diversification goes beyond the diversification of agricultural enterprises. Farmers may also have secondary occupations, engage in trade, or in migrant labor to reduce their dependency on a fickle pastoral environment. In traditional subsistence-oriented societies, this diversification lessened the dependence on the immediate environment and lessened the probability of ecological disaster.

At first glance, traditional pastoralists would appear to have been a highly specialized group dependent solely on livestock production, but in reality these societies were highly diversified. First, multiple species of animals were raised (figure 2-2). Camels, cattle, sheep, and goats all have different water requirements, feed preferences, and reproductive rates. Browsers - camels and goats - are less affected by annual fluctuations in rainfall and in grass production than cattle and sheep. Small stock such as sheep and goats have high reproduction rates when they are well nourished. They can thus be used to build up herds rapidly after droughts or to take advantage of two or three consecutive wet years. Not only did traditional pastoralists diversify their herds, but they also had other sources of livelihood. Pastoralists in the Sahara, Asia, and the Andes were often heavily involved in long distance caravan trade, in the mining of salt, and/or in military pursuits. Often they ruled or exacted tribute from sedentary groups, which provided them with agricultural products. As a result, pastoralists, like agro-pastoralists, developed diversified sources of livelihood to prevent over-reliance on any particular aspect of the environment. One consequence of this diversification was to reduce the impact of man on any single ecological niche.

Societies living in marginal areas have many institutions to facilitate diversification and mobility. One important institution is the land-tenure system. In general, the private ownership of land in such regions is rare, except in those places where irrigation or other conditions made permanent cultivation possible. Land ownership in these areas was, and still is to a large extent, collective. In areas of shifting cultivation, the cultivator had use rights to a piece of land as long as it was cultivated, but did not have an inalienable right to that land. Such rights belonged to a large group - a village, commune, clan, or tribe.

Rights to grazing lands and forest lands are also collective. However, in this case there are no user rights to individual pieces of land. Although an individual might habitually use a pasture or forest, mobility is essential to responding to fluctuations in precipitation and plant production, making exclusive assignments of land impractical. Often the boundaries between the territories of different pastoral groups are imprecisely defined, and relations of kinship and reciprocity exist that permit groups to temporarily use the pastures and forests of others. Collective ownership of pasture and forestlands is also more economical than individual tenure. The low and variable annual productivity of these lands makes the cost of maintaining fences and access roads to individual plots prohibitive. Under these conditions, if mobility is not impeded by private ownership of lands, all users of collective lands benefit from higher levels of production.
As the discussion above indicates, collective ownership of land facilitated both mobility and diversification. Therefore, a large proportion of range and forest lands remains today under the control of localities or as part of the public domain in Europe, Japan, and North America.

To say that lands are collectively owned does not imply completely open and unregulated access. That would lead to a "tragedy of the commons" situation such as that described by Hardin (1968), where individuals would each increase their herds or their use of the forests until the productive capacity of the resource was destroyed. Such unregulated exploitation of the environment ignores the fact that members of subsistence groups depend upon each other for their survival and are not individuals single-mindedly pursuing personal gain at all costs (Runge, 1981). Also, it is illogical to suggest that any group would stand by and let their subsistence base be destroyed.

The "tragedy" historically appears to occur where competition over land and its resources increases, and where differential access and market opportunities and political control reduce the effectiveness of prior regulatory procedures. Studies of traditional management systems indicate that in those areas where disease and warfare do not prevent overgrazing, a variety of institutions regulate the use of common resources. First, these lands are not open to all potential users, but are either used exclusively by certain groups, or at the very least, some groups are given priority over others. In the case of cropland, people usually need permission from local leaders or councils to use land. Even when access to pastures and woodland was technically open to all, controls over access to water, shelter, and minerals was controlled by localities or owned by individuals. For example, wells and springs are often "owned" by individuals or by small groups (Helland, 1982). Without access to water or to shelter, no one can use pastures, even if they are technically common resources.

Subsistence-oriented groups in semiarid lands do not necessarily live in harmony with nature. Pastoralists and agro-pastoralists often significantly alter the vegetation and fauna of the areas in which they live. Sometimes they do destroy the resources upon which they depend. If they do so, they quickly destroy their ability to survive and are either forced to move on or disappear. Direct dependency on the immediate environment for most subsistence needs is a strong incentive for the development of institutions to protect the environment. While most groups living in marginal areas have only rudimentary institutions, in some areas, such as southern Africa and the Atlas Mountains of Morocco, elaborate institutions evolved to regulate pasture use (Bourbouze, 1982; Gilles, 1982; and Odell, 1982). In recent years, many of the mechanisms that have traditionally served to protect vegetation have become less effective. The reasons for this decline are discussed below.

Context of environmental degradation

Typically, lands requiring revegetation have had their plant cover destroyed through improper farming methods, the extensive gathering of wood for fuel or construction purposes, or through overgrazing. In terms of destructive impact, cultivation and the gathering of woody species probably have had more impact on the environment than have grazing animals. Livestock are the primary cause of desertification only in areas where large numbers of grazing animals are concentrated, such as around boreholes. Overgrazing is, however, a major cause of vegetative change and often inhibits the restoration of plant cover.

Although these three actions of man are the main causes of environmental de gradation , the reasons for increased degradation are still debated. Four common reasons for environmental deterioration are climatic change, population growth, economic change, and human fallibility. Usually these factors interact. Over the past 30 years, the human and animal populations using semiarid and marginal lands have grown, thereby putting more pressure on the environment. Given the cycles of wet and drought years common to semiarid regions, such as the West African Sahel, this led to population growth that could only support the population in wet periods. The shortsightedness of governments and donor agencies also has contributed to environmental deterioration. In Africa in particular, ill-conceived water and livestock development projects contributed substantially to overgrazing (Bernus, 1971; Haaland, 1977). These factors have all contributed to the need for revegetation programs, but merely listing the mechanisms and factors leading to environmental problems does not explain the process by which this has occurred. Also, in many cases, destruction of plants in marginal areas has been occurring at a faster pace than have climatic or population changes. This has been due to factors that have reduced both the mobility and the diversity of traditional economies. These factors also undermined traditional mechanisms of environmental protection. The need for revegetation and conservation has been accelerated by the growth in government power, in modern economies, and in the use of improved technologies.

Changing political conditions have had severe impacts on many pastoral societies of Africa and Asia. In many cases, national boundaries were created in such a way that grazing lands used by one people were split between two or more nations. Over time, nations have incressingly restricted the movement of people and animals across frontiers . Such restrictions reduce the diversity of ecosystems available to herders and lead to herds spending longer periods of time in marginal areas than they had in the past. For example, it has been argued that the imposition of the frontier between Uganda and Kenya was the reason for overgrazing and the destruction of the pastoral economy of the Karamajong of Uganda (Quam, 1978). The imposition of national boundaries also had some impact on trading activities.

The growth of state authority has impinged on pastoral production systems in several other ways. To a large degree, governments have eliminated the raiding and warfare that often characterized the relationship between herders and their neighbors. While pacification is in itself quite desirable, it often had the effect of opening grazing lands to groups that previously did not have access to them. Often the state did not give title or the means to restrict access to grazing lands to anyone. This in effect made it impossible for communities to enforce local regulations designed to protect pastures or woodlands. Often government planners felt that local rules concerning pasture use prevented efficient meat production or impeded nation building (Sall, 1978; Cole, 1981). They wished to create a common pasture situation in which any individual who wished to raise livestock was free to do so, both to expand meat production and to combat tribalism. In many instances, these changes were accompanied by changes in herd composition. For example, cattle production increased dramatically in the northern Sahel at the expense of less destructive, better adapted forms of livestock, such as the camel (National Research Council, 1983).

The reduction of intergroup hostilities and the introduction of government land resource planning had additional impacts on the viability of traditional pastoral economies. Governments have generally sided with agriculturalists in disputes between them and pastoralists. The cessation of raiding by pastoral groups led to projects to expand agricultural production, and population pressures have contributed to the expansion of cultivated are as - further reducing the mobility of traditional pastoralists. Generally, those lands that are occupied by farmers are marginal croplands but are among the best watered and most productive pastures (figure 2-3). They are generally those used during the dry season or in winter months when the productivity of other pastures is low. The loss of these lands to farmers forces animals to remain longer on more marginal lands and increases the likelihood of erosion and desertification due to overgrazing. Even where arrangements can be made for the pasturing of animals on stubble, as is the case of much of West Africa, mobility is reduced. Such arrangements can often be developed for regular seasonal usage of pastures but not usually for occasional or for emergency use.

While governments frequently have reduced pastoral groups' land rights, in some countries there have been attempts to protect pastoralists by adjudicating land rights. French colonial authorities in North Africa attempted to adjudicate tribal boundaries, and, in East Africa, post-independence governments have attempted to delimit group ranches and grazing blocks. These attempts have in some cases restricted the growth of herds and have probably reduced overgrazing, but they also can restrict mobility if strictly enforced. As mentioned earlier, the fluid, often vague, boundaries between the areas used by different pastoral groups facilitated mobility. Overly rigid enforcement of these rules can confine animals to too small an area or, if not enforced, boundaries may be ignored. If local groups still manage resources, the fluidity of boundaries may not be a problem, but if reforms have eliminated or modified the ability to control grazing, then once again the creation of a common resource may be required where one previously did not exist.
The growth of market economies, and the adoption of new technologies that this growth permits, have also reduced the viability of tradition al resource management strategies . In a subsistence economy, one's survival is directly linked to the local environment. One exploits a wide variety of resources, but one's survival over time depends on the sustained productivity of the immediate environment. The introduction of a market economy changes this. First, one can specialize in animal production or in the cutting of fuelwood. To do so means that one can increase one's standard of living by intensely exploiting a particular environmental niche. If one is selling for cash, the feedback loop between subsistence levels and environmental conditions is less effective. If demand for one's product is rising, price increases can more than cover the loss of productivity because of overexploitation of the environment. For example, as a pasture deteriorate, a subsistence herder may only have milk and meat to eat, while a commercial beef producer may for a long time experience stable or even rising income levels.. Free labor markets also reduce the risk of degradation for the individual. The destruction of the land may cause hardship, but the possibility of wage labor in the city always exists.

In the past, some form of “passive" management occurred when quantities of stock died as a result of drought. Today, in many parts of Asia and North Africa, herders can maintain herd numbers, even when pastures and water are totally exhausted, by trucking water and feed to their animals until rains restore pastures. The purchase of feed and the delivery of water, often subsidized by governments during droughts, leads to levels of overgrazing that would be impossible for traditional subsistence pastoralists. An unintended consequence of improving veterinary services and reducing disease is to remove this “natural" regulator of herd size. Another consequence of the growth of the market economy is that individuals enjoy increased economic independence. In traditional groups, each individual family is dependent on others for survival. In such a setting, social pressure and the threat of ostracism may be sufficient to prevent deviant behavior. The development of a market economy increases economic differentiation and may reduce consensus on resource management questions.

Modernization has also contributed to the degradation of the environment in some areas Improved medical and veterinary techniques have reduced the constraints that disease placed on human and herd numbers. The development of roads and the introduction of motor transport have caused some nomads to become more dependent on herding as caravans have become less profitable and have probably encouraged the switch from camels to cattle. Roads and trucks have also made it profitable to cut fuelwood or produce charcoal at great distances from cities, and trucks make it possible to increase the use of remote or poorly watered pastures (Thalen, 1979). In many cases, mechanized plowing and sowing have made it profitable to plow up rangelands where rainfall is so erratic that only one year in three witnessed successful harvests. The introduction of new technologies often requires changes in traditional institutions, hence an unintended consequence may be a weakening of those institutions that have in the past protected the environment. In this light, publicly funded revegetation programs may be seen as attempts to correct some of the excesses of rapid social change.

As we can see, then, desertification and the destruction of plant cover have been caused by a number of factors. It is important to remember from these examples that environmental deterioration has been accelerated because the mechanisms that formerly helped people adapt to semiarid and marginal environments have been weakened. Diversification and mobility have been limited, and the feedback from man's use of the environment has been distorted. If revegetation efforts are to be successful, they must create a sustainable human ecology as well as stable, productive environmental systems. Too often, projects have undermined themselves by ignoring people, or by inadvertently accelerating the processes of declining diversity and mobility in production systems.

Successful revegetation requires changes in land use patterns so that the reestablishment of vegetation is encouraged. In the past, attempts have been made to control access to revegetated areas by changing land tenure arrangements. Nomads have been settled, private and group ranches have been created, and forest reserves have been legislated, all in attempts to control access to project lands by reducing animal movement and by restricting people to particular parcels of land. As previously mentioned, the reduction of mobility may threaten the viability of traditional subsistence systems. If their livelihood is threatened, people may resist overtly or may passively resist by bribing forest guards or by grazing or cutting revegetated areas when they are not being properly guarded. Conflict between traditional users at the very least raises the cost of revegetation substantially, and may in many instances negate project efforts.

In some cases, the failure to understand the importance of mobility can mean disaster even when project goals are attained. Boreholes are examples of efforts to increase available pastures that, in fact, led to local desertification and to heavy livestock losses during droughts (figure 2-4). At other times, the success of programs in one area may lead to larger levels of environmental deterioration outside a project are a . Herds that are required to leave the are a of a range or reforestation project must go somewhere, hence the revegetation projects may accelerate the processes that they are intended to reverse. The settlement of nomads may increase overgrazing, as we saw in the Sudanese example (Haaland, 1977). The creation of private ranches or group ranches may improve the conditions of ranges in their boundaries, as it has in some parts of Kenya (Hopcraft, 1981; and case study 10). If ranchers are not excluded from common pastures they may use their individual pastures as reserves, which permits them to exploit other lands more intensively (Little, 1983). In a similar vein, people may preemptively destroy an area rather than have it come under the control of a public range or forestry program. Pascon (1980) cites the example of herders in Morocco who, when presented with the successful establishment of wheat grass on overgrazed plain, chose to plow up the entire region and plant wheat rather than give up control of their resources to a range management scheme. These examples, though perhaps more graphic than most, are typical of many attempts at revegetation.

Those who plan revegetation efforts often face a dilemma. Successful programs may require the use of coercion and force, which, in turn, raises the cost of revegetation, reduces the extent of the area that can be treated, and reduces cooperation. This is one part of the dilemma - coercion reduces the program area. On the other hand, success in a limited area may be illusory; vegetation may be protected at the cost of widespread environmental destruction in adjacent areas. This is a cruel dilemma.

In part, this difficulty can be overcome if rehabilitation efforts are carefully reconciled with local systems of production. If one understands how a revegetation program will impact on an area, one may be able to make adjustments in other parts of the local production system to compensate for disturbances caused by a program. Instead of paying money for guards, it may be possible to plant highly valued, multiple-use species that would strengthen and diversify the local economy, thereby justifying protection by local populations. Approaches can be developed that enhance the advantages of mobility and diversity for production systems in these areas. The creation of new jobs or economic activities may have a greater impact on the environment than the creation of forest or grazing reserves.

Given sufficient time and money, it is possible for planners to characterize a production system and to design appropriate revegetation programs. An easier approach may be to reduce technical input, but to work closely with local populations to identify appropriate types of interventions and to monitor the program. Such an effort may succeed in areas where government policies have often undermined local institutions.

It is of particular importance that environmental rehabilitation projects yield multiple benefits. Multiple uses of vegetation should be encouraged. Local involvement should reduce management costs through increased self-enforcement of conservation rules. Finally, the project should help reestablish a local sustainable resource system that is not dependent on the vagaries of public funding and political will. There may often be some trade-offs between the efficiency of revegetation and local involvement. There may be more efficient and more effective ways of conserving and protecting plant cover than those acceptable to local populations. For example, the policies developed by ranchers and the Grazing Service in the United States under the Taylor Grazing Act did not satisfy many conservationists, but they could be implemented effectively and did lead to improved range conditions in the western United States (Foss, 1960; U.S. Forest Service, 1979). The goal of any revegetation program should be to create a viable environment for plants, animals, and people. This can be done only by placing revegetation efforts within the context of local and regional production systems.

References

Bernus, E. 1971. Possibilities and limits of pastoral watering plans in the Nigerian Sahel. Paper presented at the FAO Symposium on Nomadism, Cairo, Egypt.

Bernus, E. and G. Savonnet. 1973. Les problmes de la scheresse dans l'Afrique de l'Ouest. Prsence Africaine 88:112-138.

Bourbouze, A. 1982. Dplacements des troupeaux et utilization des parcours dans le Haut Atlas Central. Product 'on Pastorale et Socit 10(Spring):34-45.

Breman, H. and C. T. deWit. 1983. Rangeland productivity and exploitation in the Sahel. Science 221(1):1341-1342.

Cole, D. P. 1981. Bedouin and social change in Saudi Arabia. Journal of Asian and African Studies 16(1-2):128-149.

Foss, P. O. 1960. The Politics of Grass: Administration of Grazing on the Public Domain. University of Washington Press, Seattle, Washington, USA.

Gallais, J., ed. 1977. Stratgies Pastorales et Agricoles durant la Scheresse 1969-1974. Centre d'tudes de Gographie Tropicale, Talence, France.

Gilles, J. 1982. Organizing for pastoral development: Themes from traditional sytems. Agricultural Administration 11:215-225.

Gilles, J. L. and K. Jamtgaard. 1981. Overgrazing in pastoral areas: The commons reconsidered. Sociologia Ruralis 21:129-141.

Haaland, G. 1977. Pastoral systems of production: the sociocultural context and some economic and ecological implications. Pp. 179-193 in Land Use and Development, P. O'Keefe and B. Wisner, eds. International African Institute, London, England.

Hardin, G. 1968. The tragedy of the commons. Science 162:1243-1248.

Helland, J. 1982. Social organization and water control among the Boran. Development and Change 13(1):239-258.

Hopcraft, D. N. 1981. Economic institutions and pastoral resource management: considerations for a development strategy. Pp. 224-243 in: The Future of Pastoral Peoples J.G. Galaty, D. Aronson, P.C. Salzman and A. Chouinard, eds. International Development Research Centre, Ottawa, Canada.

Little, P. D. 1983. Businessmen and part-time pastoralists: some factors affecting drought and overgrazing in Baringo District, Kenya. Paper presented at the 149th Annual Meeting of the American Association for the Advancement of Science, Detroit, Michigan, USA.

National Research Council. 1983. Environmental Change in the West African Sahel. Board on Science and Technology for International Development. National Academy Press, Washington, D.C., USA.

Odell, M. J. 1982. Location, institutions and management of communal resources: lessons from Africa and India. ODI Pastoral Network; Paper, no. 14e, Overseas Development Institute, London, England.

Pascon, P. 1980. La comptition des lveurs dans la rgion d'Azrou. Pp. 61-72 in tudes rurales: Ides et enqutes sur la campagne Marocaine. Socit Marocaine des diteurs Runis, Rabat, Morocco.

Quam, M. D. 1978. Cattle marketing and pastoral conservatism. African Studices Review 21:49-71.

Runge, C. F. 1981. Common property externalities: Isolation, assurance, and resource depletion in a tradition al grazing context . American Journal of Agricultural Economics 63:595-606.

Sall, A. 1978. Quel amnagement pastoral pour le Sahel. Revue Tiers Monde 19(73):161-169.

Thalen, D. C. P. 1979. Ecology and Utilization of Desert Shrub Rangelands in Iraq. Dr. W. Junk, The Hague, Netherlands.

U.S. Department of Agriculture Forest Service. 1979. Rangeland Policices for the Future. Government Printing Office, Washington, D.C., USA.

Wagner, F. J. 1983. Nomadic pastoralism: Ecological adjustment to the realities of arid environments. Paper presented at the 149th Annual Meeting of the American Association for the Advancement of Science, Detroit, Michigan, USA.

Western, D. 1982. The environment and ecology of pastoralists in arid savannas. Development and Change 13(2):183-211.

The economic context

The previous chapter dealt with the behavioral characteristics of groups of people living on, or using, arid and semiarid lands. This chapter focuses on the economic behavior of the individual or the individual household.

Economic analysis of pastoral management practices has proved difficult for several reasons. First, many analysts have a tendency to consider the household as one homogeneous decision-making unit, with the "head" of the household as the decision-making director. In fact, households are heterogeneous and not always clearly defined, and decision-making is generally delegated to a large number of individual household members who may not share the same interests. Surveys that used the (male) family head as the sampling or observation unit have therefore yielded incomplete or biased data, leading to biased conclusions.

Second, many studies have limited the focus of the analysis to one aspect of household activities - only land management or only animal performance, for example. These single-commodity approaches fail to incorporate interactions among various household enterprises. Therefore, the predictive value of the analysis for household behavior is low.

Third, any economic analysis is based upon the identification of determinants and their impact. Even when successful in identifying important factors, allocating values ("impact") to these factors has proved extremely difficult. In resource-poor environments such as arid rangelands, the assessment of values is highly time- and location specific. Not only do values vary over time and space, but also among individuals, households, tribes, and generations. The cost (negative value) of soil degradation will be felt more by future generations than by present ones (who might be causing the degradation).

Fourth, and related to the third point, is the difficulty in assessing the social costs and benefits (as opposed to the private values). Communal grazing is believed to occur with virtually no cost to the herders, but with possible social costs (in the case of overgrazing) to the society as a whole. In the same vein, the long-term costs are not necessarily the same as the short-term costs. This problem is aggravated by the fact that the life span of range management projects is generally limited to 10 years or less, even in projects that attempt to deal with long-term problems, such as desertification and erosion. Another example of social costs is the negative effect that a project might have on resources or persons outside the project are a . For example , the development of a pocket of highly productive rangeland for crop cultivation might have a negative impact on the usefulness of the surrounding low-quality rangeland because during a drought period cattle would not have access to a highly productive forage source (Sanford, 1983). Other social costs or benefits include the impact of interventions on employment and equity.

Finally, we cannot overlook the fact that many projects have failed for reasons other than inadequate economic analysis. For example, biological scientists and technicians have often provided projects with short-term, single-commodity technical input-output relationships that have contributed to illusionary expectations of possible changes in management behavior.

For some time, pastoralists have therefore been labeled "irrational," but this allegation has been refuted by a growing number of case studies. Cattle portfolio models developed in industrial countries have found useful applications in pastoral situations (Jarvis, 1980; Ariza-Nino and Shapiro, 1984), and elements of African and Asian range management systems are finding application in industrialized countries (National Research Council, 1984).

Range systems

A range system is the arrangement of soils, water, crops, livestock, labor, and other resources that the manager works according to personal preferences, capabilities, and available technologies. The major factors that influence productivity are determined by the characteristics and interactions of (1) the physical environment, (2) the economic environment, and (3) the social environment. Subsystems can be recognized within range systems. Interdependencies and interactions among resources (land, labor, crops, livestock, capital, water, wood), environment (climate, topography, soil, market), and humans (family members, relatives, friends, enemies) are essential components of the analysis.

The tools for the economic analysis of range systems are essentially the same as those for conventional farm management studies: budget analysis by gross margins or partial budgeting, linear programming, and discount procedures. However, when these methods are applied to a range system, the results have become more reliable, essentially because previously unidentified factors (inputs as well as outputs) are taken into account.

Little (1984), however, recommending the systems approach, also points to two major limitations: the assumption that the household is the proper unit of analysis, and the lack of focus on macro and micro linkages in problem solving. He therefore recommends a combination of household production and regional analysis.

Rangeland management systems have been divided into two major systems: nomadic and transhumant. Another distinction is based on land ownership - that is, pastoral nomadic, open-range ranching, and fenced ranching (Behke, 1984; Lawry et al., 1984). This distinction is addressed in a later section of this chapter.

Rangeland Farming Systems

Within the framework of range systems analysis, relatively little work has been done on livestock-related issues. Several reasons account for this neglect:

· Most of the research is done by crop-oriented agronomists and social scientists, neither of whom are familiar with livestock and therefore tend to overlook their role.
· Most of the livestock have multiple outputs (such as draft power, meat, milk, manure, hides, status) and non-cash inputs (especially for ruminants).
· A substantial part of these outputs is used within the household (for example, draft, manure), and therefore only indirectly contributes to the cash income of the pastoralist.
· The cash income from livestock activities often occurs at irregular intervals and on special occasions; it is easily if not intentionally overlooked during household surveys (Sabrani and Knipscheer, 1982). Even if scientists have explicitly focused on the livestock component of the range system, they have encountered a number of additional problems. Table 3-1 compares livestock-oriented farming systems research with crop-oriented farming systems. Factors such as genetic variability, differences in age and productivity, and problems with farmer cooperation, measurement of effects of input and output, and representativeness of prices have constrained the researcher in conducting on-farm trials (Amir et al., 1985). Consequently, rangeland research has proved to be time-consuming, logistically difficult, and expensive.

Major Features of Nomadic Systems

Nomadic systems are based on livestock, and the main source of income is derived from meat and animal by-products. Typical for nomadic systems is the annual migration of livestock and managers, for example, from highlands in the summer to plains in the winter, as in the arid and semiarid region of Asia. The influence of climate as well as culture is large, as families or tribes or both travel together, following the opportunities that the climate offers. In this kind of culture, crop farming is held in low regard. The crop component in nomadic production systems is virtually nonexistent. The linkages between livestock and other household activities are found in household processing (for example, wool and weaving) and fuel supply. Land use is characterized by grazing and collection of fuelwood, while the manure of the animals returns some of the nutrients to the soil. Although nomads generally are believed to be unconcerned with improvement of feed resources, it is also known that they are aware of the importance of future pasture availability and, therefore, are careful in their grazing practices (Camoens et al., 1985).

Major Features of Transhumant Systems

The critical difference between nomads and transhumants is the existence of a substantial crop-producing activity in the household system. Transhumants migrate seasonally with their flocks but have a permanent residence area. The crop enterprise is generally for subsistence, while the livestock component is geared for the market.

TABLE 3-1 Comparison of Characteristics of Crops and Livestock and Implications for On-Farm Testing

TABLE 3-1 Comparison of Characteristics of Crops and Livestock and Implications for On-Farm Testing

	Situation with respect to:
Factor	Crops	Livestock	Implications
Mobility	Stationary	Mobile	Difficult to measure and control non experimental factors
Life cycle	Generally less than 4 months	Generally over one year	Increases costs likelihood of losing experi mental units
Life cycle	All units synchronized	Units seldom synchronized	Difficult to find comparable units
Multiple	Only grain and/or tuber and residue	Multiple ouputs, mest, hides, milk manure, power	Difficult to measure or evaluate treatment effect
Nonmarket	Few	Many	Difficult to evaluate input or outputs
Experimental unit size	Small divisible	Large nondivisible	Increases cost risk to cooperate
Producer attitude	Impersonal taboos	Personal cull, castrate towards	Difficult to product
Management variability	Low	High	Difficult to isolate treatment effect
Observation units	Many	Few	Large statistical variability

SOURCE: Bernsten et al., 1983.

Climate and culture play dominant roles in transhumant systems, comparable to those of the nomadic systems. Because of the crop activities, some of the land is privately owned (or rented). Some of the large ruminants are used for draft purposes, but the application of manure provides a linkage between the livestock and the crop component of this farming system.

The common feature of both the nomadic and the transhumant farming systems is the mobility of the households. This strategy to meet the variability in the physical environment is associated with unstable control of resources, notably land and water, and difficulties of planning herd size and herd movements.

Ownership

The three types of land ownership are communal, modified communal, and exclusive (Lawry et al., 1984). Exclusive land tenure (private ownership or lease) has been seen by some as a solution to overgrazing. Overgrazing in turn is believed to find its economic rationale in the "tragedy of the commons": the individual herdsman has no economic incentive to reduce the number of animals as long as there is free access to communal land and water. Although assignment of grazing rights is advocated as a solution (Doran et al., 1974; Jarvis, 1980), experience has not yet shown that tenure reform is an effective policy instrument (Lawry et al., 1984, p. 247). One of the problems is that stock limitations specified in leases are almost never enforced. There is also growing evidence that pastoralists are very aware of the need for rangeland conservation and will act accordingly (National Research Council, 1986).

Narrowly related to the issue of land ownership is that of access to water. Because moisture is the overriding limiting factor in pastoral management, access to water is crucial. In many cases, control of water supply implies de facto control of land use. Water sources can be classified according to ownership in a similar way. Other classifications are made according to the technical operations (including boreholes, dams, wells) or size.

The basis of range economics

Economics may be defined as the science dealing with the allocation of scarce resources among various competing uses, with the objective of maximizing utility or maximizing satisfaction of human wants. For range projects, scarce resources include:

· Land. In the broadest sense, land includes all natural resources such as air, minerals, soils, natural vegetation, and water.
· Labor and management. These are the resources furnished directly by humans.
· Capital. This refers to the intermediate products (inputs) created from land, labor, and funds used in further production. Capital is both the money used to pay for inputs, and the buildings, machinery, livestock, and purchased inputs that can be valued in dollars or local currency.

Organizations must conscientiously attempt to guide the allocation of their physical, financial, and administrative resources among sectors and competing programs to further national objectives (figure 3-1). This is true whether the resources committed are being invested by the government directly or by individuals within the economy.

The concept of economic rationality is a central consideration of economic theory and the definition given above. A rational economic person, or consumer, is one who seeks to maximize utility or satisfaction. There is often a close identification between farmers' or pastoralists' consumption and their production decisions.

Personal preferences also affect decisions within the agricultural or natural resource development sphere. Some decisions may be made to enhance prestige or status with a peer group. Some may reflect consumption rather than production expenditures.

As mentioned previously, however, nonrational behavior may be difficult to judge, in particular by those outside the culture. What seems nonrational to an urban dweller from the industrilized world may be quite rational when examined in the correct cultural context. Therefore, in determining proper economic behavior, what outsiders consider maximum utility may not be in the best long-term interest of pastoralists. Clearly, before a rational economic strategy can be formulated, the culture and traditional economic behavior must be understood.

Project analysis

Agricultural or natural resource developments might best be defined, explained, analyzed, and understood as “projects.” Projected cash flows over a period of time are required for comparisons among alternative development projects or other investment decisions.

In defining a project, Gittinger (1982) said:

FIGURE 3-1 Pastoral Economies.

We generally think of an agricultural project as an investment activity in which financial resources are expended to create capital assets that produce benefits over an extended period of time. In some projects, however, costs are incurred for production expenses or maintenance from which benefits can normally be expected quickly, usually within about a year.

Range or marginal land development projects (such as seeding) can be viewed in the same terms as an agricultural project, although the investments, costs, and returns may be substantially different in substance and in timing of flows. For example, the returns on a rehabilitation project may take several years to realize depending on the starting conditions and project management. These returns, however, may be in the form of higher stocking rates, which may have caused the problem in the first place.

An alternative approach is to examine potential losses that are avoided through rehabilitation. This approach is similar to determining the benefits of flood control projects. If degradation is not halted, then adjacent agricultural land may be placed at risk.

Gittinger also distinguishes between a project that may be relatively small, or perhaps quite large, but is of a nature that it can be analyzed, evaluated, developed, and administered as a unit. A "program" would typically be larger than a single project, and encompass multiple projects or aspects of development that are beyond the project definition and boundaries.

A project should contain relatively homogeneous resources so that investment requirements, costs, and returns from different parts within the project can be accurately represented. If a project becomes large enough to become heterogeneous, then a part of the project - which may in fact be uneconomical or unfeasible - may be hidden or masked and carried by other parts of the project that are worthy of development. When dealing with scarce resources, the concept of homogeneity within a project is important. Past experience has shown that in many instances projects have failed because of lack of social homogeneity; that is, within the target group of pastoralists, subgroups with contrary interests existed (see, for example, Sanford, 1983).

Economic and Financial Analyses

By definition, the economic analysis compares all returns and costs associated with a project during its useful life. Costs include initial and recurring annual expenditures, whereas the revenues include returns as a result of the project over and above what they would have been without it.

Financial or cash flow analysis is the determination of the project's cash flow positions over the period of the project. This shows whether the project is self-supporting or whether deficits are likely to develop. It is simply to compare revenues and expenditures, including debt service on an annual cash basis. The objective of financial analysis is to consider and make estimates of the effects the flow of project costs and returns will have on people participating directly in the project, including families or community groups that make direct use of the project and the primary users. Financial analyses also must consider administration, management, and taxes of the project and costs to the government and donors for those activities.

In financial analyses, market prices, if available, are used to reflect the value of production. Project returns may also include a very significant contribution in the form of food or fuel consumed directly in the household. If subsidies are paid by the government in association with the development of a project, then that also becomes part of the income to the direct beneficiaries from the standpoint of financial analysis. Financial analysis also considers revenue to the goveronment (taxes) for project administration, which have been considered in the costs of the primary beneficiaries (users).

The "economic" aspects of project analyses and evaluation, in contrast to financial aspects, considers the project from the standpoint of the affected society and economy as a whole. Financial and economic analyses differ in three significant ways:

1. Taxes that are treated as costs to primary project participants in financial analyses are viewed by government and society as revenues, not costs.
2. In economic analysis, market prices may be adjusted and become "shadow" or "accounting" prices or “social costs/benefits" to reflect more accurately the economic values to society.
3. In economic analysis, interest on capital and repayment of borrowed capital are not treated as project costs. Although interest is a cost to the project, it is a return to society and the economy as a whole, if actually earned, and hence becomes a "wash" item in economic analysis and accounting for the project. Similarly, the repayment of borrowed capital, although a requirement for the project, neither increases nor decreases net national product.

Comparison Without and With a Project

The purpose of project analysis is to identify and estimate benefits and costs that will arise "without" the project and compare them with benefits and costs "with" the proposed project. The difference between them is the incremental or marginal net benefit arising from the project.

The results of the without-with comparisons may be the same as comparing a particular project situation "before" and "after." Often, however, the comparisons are not the same and may be greatly different because productivity may improve (increase) even without a project. Hence, the projection of the without situation would reflect higher productivity and returns than the current or before project situation. The benefits from a project designed to improve productivity at a more rapid rate than would occur without the project would be overstated by a before and after comparison, because improvements without the project are ignored.

Conversely, a different, perhaps more common, and certainly more serious situation could be one of rapid deterioration in productivity and resource or environmental conditions without a project. A project could be designed with the aim of ameliorating or reversing the deterioration; improved productivity could be a distinct bonus. It may therefore be difficult to compare or economically justify such a project when it may only retard the rate of degradation and keep the returns constant. Intangible benefits must then be considered such as the quality of the environment and the costs associated with people moving to urban centers to escape declining land productivity.

Decision Making

A decision needs to be taken that leads to implementation, modification, or cancellation of the project. Certain costs and benefits (payoffs) are associated with any of these decisions. The decision may be to endorse the project and proceed with implementation based on a degree of uncertainty.

Problems and sources of uncertainty are classified in five categories:

1. Price structures and changes (values)
2. Production methods and responses, including weather effects and other natural phenomena (technical input/output coefficients)
3. Prospective technological developments
4. The behavior and capacities of people associated with the project
5. The economic, political, and social contexts in which a range improvement project exists.

All these sources of uncertainty affect the analysis of projects and are factors to be reckoned with in implementation and evaluation of results.

The basic principle for carrying out an economic analysis is to compare alternatives on an equivalent basis, such as a fixed output, time frame, and constant dollar values. In the analysis, the quantifiable assumptions must first be established as follows:

· All baseline project assumptions, such as the period of analysis, discount rate, cost of capital, and other economic and financial variables must be determined.
· Estimates must be made of project costs including capital costs, onetime costs such as permits, annual operating and maintenance costs, and provisions for renewals and replacements. Estimates of fees, construction, labor and materials, and legal fees must all be determined and placed within the desired schedule.
· Project benefits, principally the increased production, must be ascertained.
· The source of financing and the specific terms of the loan must be defined.
· An appropriate economic analysis methodology must be chosen, and economic and financial feasibility must be established.
· A sensitivity analysis must be performed to determine how costs and benefits react to variations in such factors as discount rate, financing, and productivity.
· The persons or groups of persons who gain and who lose by the introduction of the project must be identified; there are always some losers.

The common approach to economic analyses has been to compare costs and revenues over a consistent time period on a ratio basis or net positive benefit basis. Several measures using discounted cash flow techniques can be employed: internal rate of return, benefit-cost ratio, net present value, and life-cycle costs. Each technique has its advantages, disadvantages, and appropriate applications.

Discount Rate

The discount rate is used for determining economic feasibility, whereas the interest rate is used to ascertain financial feasibility. The proper rate to use for testing economic feasibility is the opportunity cost of capital to society. This is the rate of return that could be earned by investing the capital cost of the project in a venture of similar risk or an alternative marginal project.

Discounted Cash Flow

One of the basic tools for determining economic feasibility is discounted cash flow. All cash expenditures are tabulated for comparison during the chosen period each year. The total cash expenditure for each year is then discounted to the present and cumulatively added to a single sum. This sum is then compared with similar sums of discounted expenditures for alternatives. The alternative with the smallest sum is clearly the least costly. A similar comparison is made with cash revenues or receipts for the same period. The ratio between the sum of the discounted receipts and the sum of the discounted expenditures yields the benefit-cost ratio.

Certain rules must be followed in making discounted cash flow analyses:

· The same period of years must be used for each alternative set of cash expenditures and each alternative set of cash receipts.
· The alternatives must have the same production and capacity. In some cases, this may require adjustments to the costs of the lowest cost alternative.
· Cash expenditures will include renewals and replacements; however, if the years in which these will be made cannot be accurately predicted, an estimated average annual cash expenditure for renewals and replacements as well as an accelerated depreciation schedule can be used, since those costs will occur far in the future.

Discounting transforms all future costs and revenues into the present time frame so they can be compared on a current monetary basis. These sums are simply called the present worth or present value. All future expenditures and revenues are modified or discounted by a factor that provides escalation arising from opportunity costs and resource depletion.

The benefit-cost ratio technique is perhaps the most commonly applied in analyzing capital projects. The method compares the current worth of costs and benefits on a ratio basis. Projects with a ratio of less than one are generally discarded.

Determining costs and benefits

Computing costs and benefits involves use of simple without with comparisons. Specific allowances are not made for time lags, except for charging interest for use of capital. Budgeting in such a static framework, or without-with project-context comparisons, can give a first indication of feasibility or nonfeasibility of a rangeresource-improvement project. Simple comparisons ignore time lags in phasing different stages into production and can overlook or ignore costs of capital through the developmental stages, exaggerate returns and feasibility, and underestimate problems that can arise. Budgeting year-to-year estimated changes through the transition period, though complicated, will aid in anticipating some of those problems. If the project resources are suitable and the project is successful, changes in physical production responses on a year-to-year basis may be predictable with some degree of certainty. Price changes often are unpredictable. Evaluations can be based on longer term average prices with year-to-year changes in production. Discounting procedures can be used to allow for valid comparisons of alternatives through time.

Benefits that might accrue from and be attributed to range-improvement projects may include increases in both the quality and quantity of outputs, depending on factors previously mentioned. When considering a