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Chapter 2: Livestock grazing systems & the environment
Grazing systems of the arid areas
Grazing systems in the semi-arid and sub-humid tropics
Grazing systems and tropical rainforests
Grazing systems in temperate zones
Livestock grazing systems & the environment
ABOUT 60 PERCENT of the world's pasture land (about 2.2 million km2), just less than half the world's usable surface is covered by grazing systems. Distributed between arid, semi arid and sub humid, humid, temperate and tropical highlands zones, this supports about 360 million cattle (half of which are in the humid savannas), and over 600 million sheep and goats, mostly in the arid rangelands. The distribution of livestock over the different ecological zones is provided in Annex Table 2.
Grazing systems supply about 9 percent of the world's production of beef and about 30 percent of the world's production of sheep and goat meat. For an estimated 100 million people in arid areas, and probably a similar number in other zones, grazing livestock is the only possible source of livelihood.
Grazing can be visualized as beautiful cows in lush pastures in north-western Europe or New Zealand-livestock in harmony with nature. Indeed, livestock can improve soil and vegetation cover and plant and animal biodiversity, as described in this chapter's case studies of widely different conditions in Kenya, the western United States and Guinea. By removing biomass, which otherwise might provide the fuel for bush fires, by controlling shrub growth and by dispersing seeds through their hoofs and manure, grazing animals can improve plant species composition. In addition, trampling can stimulate grass tillering, improve seed germination and break-up hard soil crusts.
However, many people associate grazing animals with overgrazing, soil degradation and deforestation. To them livestock keeping in arid regions of the tropics provokes images of clouds of dust, bleached cow skeletons and an advancing desert. The two most quoted sources are the Global Assessment of Soil Degradation (Oldeman et al., 1991), which estimates that 680 million hectares of rangeland have become degraded since 1945, and Dregne et al., (1991) who argue that 73 percent of the world's 4.5 billion hectares of rangeland is moderately or severely degraded. In humid areas, livestock are associated with ranch encroachment and deforestation of tropical rainforests and competition with wildlife.
Prolonged heavy grazing undoubtedly contributes to the disappearance of palatable species and the subsequent dominance by other, less palatable, herbaceous plants or bushes. Such loss of plant and, in consequence, animal biodiversity can require a long regenerative cycle (30 years in savannas, 100 years in rainforests). Excessive livestock grazing also causes soil compaction and erosion, decreased soil fertility and water infiltration, and a loss in organic matter content and water storage capacity. On the other hand, total absence of grazing also reduces biodiversity because a thick canopy of shrubs and trees develops which intercepts light and moisture and results in overprotected plant communities which are susceptible to natural disasters.
The environmental challenge is thus to identify the policies, institutions and technologies which will enhance the positive and mitigate the negative effects of grazing. Environmental challenges, issues and options differ significantly according to climate and land capabilities. Livestock-environment interactions are therefore described separately for the arid, semi-arid and sub-humid, humid rainforest, and temperate and tropical highlands grazing systems respectively. As will be seen, that differentiation is particularly important for the arid eco-systems. As aridity increases, so does variability of rainfall, to the extent that the periodicity of rain becomes the single most important factor affecting the state of the natural resource base. Classical concepts of vegetation succession and climax vegetation do not apply in such environments and new concepts are required. These are detailed below.
Grazing systems of the arid areas
Response: Technology and policy options
Land. Probably more than any other system, at least until recently, arid rangelands1 have been associated with land degradation. The concept of "desertification" originated from the sight of degrading fringes of arid rangelands and advancing deserts. In addition, arid grazing systems and nomadic pastoralism have been associated with inefficient and backward production.
1 Arid rangelands refers to land with mostly native and annual vegetation, with an average growing season of less than 75 days.
Area of Sahara desert (million km2)
The type of variation presented in this graph highlights the difficulty in obtaining an accurate assessment of land degradation in arid areas.
Box 2.1 The resilience of the arid lands.
GRAPH how the Sahara expands and contracts over time (and
conversely the Sahelian rangelands contract and expand)
as measured infrared reflection of the vegetation. it
shows the effect of the dry year of 1984 (rainfall
deficit of 55%) and the recovery in 1988 (rainfall
deficit of 19%)
Over the last decade these views have changed radically. First, there is now significant evidence that in the arid zones the extent of land degradation is greatly exaggerated. Part of the doom view of continuing degradation is caused by problems of definition and time frame. Definitions were based on parameters, which could not easily be measured ("diminution or destruction of biological material, which can lead to desert-like conditions" (UN 1977), or mixed process and end state ("the expression of natural, economic and social processes, which destroy the equilibrium of soil, vegetation, air and water" (FAO/UNEP, 1984)). Even more importantly, most assessments covered only a short period, and did not include the concept of reversibility, which seems critical from a development and long term sustainability perspective (Nelson, 1990). If desertification is defined as an irreversible process of land degradation, there is less "desertification" than previously claimed. Two recent findings support this view:
Long term monitoring of the infra-red reflection index (measuring the amount of green biomass) by NASA in West Africa (Tucker et al., 1991), clearly shows the "contracting and expanding Sahara", rather than a continuously expanding desert (see Box 2.1). More recent observations confirm this earlier finding. In effect, the northern vegetation limit of the Sahel is now approximately where it was in 1970 (Tucker, personal communication);
An analysis, carried out under this study, shows an overall increase in productivity of Sahelian land and livestock (Box 2.2) albeit with considerable year to year variations. While this increase in productivity is undoubtedly the result of several factors, it certainly does not point to the continuing downward spiral in pasture production, and hence productivity, which has traditionally been assumed.
Series of vegetation of Mali in consecutive years at the same time each year (a)
Series of vegetation of Mali in consecutive years at the same time each year (b)
Series of vegetation of Mali in consecutive years at the same time each year (c)
Photo series of a vegetation of Mali in consecutive years at the same time each year Courtesy ILCA.
Secondly, there is convincing evidence that traditional transhumance production systems on arid rangelands are highly efficient. Studies show that production of protein per hectare of traditional nomadic pastoralists in Mali and Botswana is two- or three-fold higher (and at much lower cost in non-renewable fuel resources) than production from sedentary production systems or ranching under similar climatic conditions in Australia and the USA respectively (Breman and de Wit, 1983, de Ridder and Wagenaar, 1984). In addition, arid grazing systems are often multiple-use systems, with wildlife and other plant products being important additional products.
Productivity trends in the Sahel.
Box 2.2 Productivity trends in the Sahel.
AN ANALYSIS of livestock production in five Sahelian countries over a thirty year period, carried out as part of this study, shows a 93 percent increase in the meat produced per ha, and 47 percent increase in the meat produced per head. At the same time, there was a 22 percent increase in the animal population (from 14.5 to 17.6 million TLU2) over the same period.
productivity increase occurs in both cattle and small
ruminants. Part of the increased productivity may be the
result of a progressive shift of the livestock population
to the higher potential areas in more humid zones, and
the increased use of crop residues. However, apart from
the sharp inter-annual variation, the long term trend
points to sustained productivity, and to an obviously
stable resource base.
Source: Analysis carried out under this study, based on FAO production data.
The greatest degradation of land and vegetation is around settlements and water points. These areas are usually within a radius of about 1-5 km of the waterpoint and often look quite spectacular. However, assuming an average distance of 10 to 30 km between waterpoints, degraded areas would, even in the worst cases, amount to no more than 10 percent of the total area.
Biodiversity. Arid rangelands contain a broad variety of plant species for wild and domestic herbivores. For example, Le Houerou (1989) estimates that, in Africa, there are perhaps as many as 3,500 plant species upon which the continent's herbivores feed, compared with less than 150 species on which humans depend. There is no widespread risk of an immediate irreversible loss of plant biodiversity. Mixed grazing systems (cattle, small ruminants, camels and wildlife) help to maintain wide plant diversity and, because the vegetation is extremely resilient, any changes in the vegetation are likely to be the result of an unusually dry period and, therefore, temporary.
Underlying pressures. The way most dryland ecosystems are traditionally used explains, to a large extent, their resilience. Arid rangelands have traditionally been used under a communal property regime by nomadic producers who move their stock in search of pasture according to season. From the wet season grazing they will move their animals to higher-potential river valleys, cropland or mountain meadows (the "key resources") for the dry season. With highly variable rainfall (both in time and space), pastoral economies are typically of the "bust and boom" type: a "boom" when rainfall is plentiful and herds and flocks grow, and a "bust" when drought (or late winter storms in Central Asia) occurs and animals die. Thus, abiotic factors such as rainfall, rather than livestock density, determine long term primary production and vegetation cover (Mearns, 1996).
This continuous dis-equilibrium conserves soil and vegetation, especially annual vegetation in more arid areas, because grazing pressure has to adjust to the quantity of feed available. The theoretical bases for range management under those conditions ("opportunistic range management") have recently been well described by Behnke, Scoones and Kerven (1993) and Scoones (1994).
A substantial body of evidence from the last decade (Thomas and Middleton, 1994), shows that arid regions contain dynamic and highly resilient ecosystems, with a strong capacity to regenerate rapidly when the rains return. Similarly, traditional pastoral systems have conserved biodiversity because pastoralists have a direct interest in preserving a wide variety of plants and animals. Gathering range products, such as medicinal plants, gums and resins, is an important part of the pastoral way of life.
The fundamental driving force on natural resources is population pressure, especially that applied from outside the arid rangelands and their traditional inhabitants. While population growth of pastoral peoples has been slow (Pratt et al., in press), growth of non-pastoral groups in the arid and semi-arid regions have been among the highest in the world. This strong growth of other groups results in an increasing encroachment by arable farmers on to the pastoralists' "key resource" sites. Flood plains which have been traditionally used for wet season grazing, such as the Interior Delta of the Niger and the Senegal Valley in West Africa, and also smaller sites of high potential, are being converted into cropland. Furthermore, flexibility of animal movement is progressively hampered by increased population pressure and loss of corridors between wet and dry season grazing areas. Stock is increasingly concentrated the entire year on the same lands, breaking the ecologically sound cycle of alternating use of wet and dry season grazing areas, leading to over-use of dry season grazing land and, inevitably, to human suffering. Such increased pressure often results in war, as shown by the recent confrontation between Senegal and Mauritania and the many armed conflicts in East Africa.
Increased population pressure also leads to greater water development and permanent human settlement in arid rangelands. Although the direct effect of waterpoints on land degradation is relatively limited, the development of water supplies for more intensive use can upset an entire eco-system. It may lead to de facto privatization of land around the water point (IFAD, 1995) and change the relationship between traditional wet and dry season grazing areas, changing traditional dry season grazing into year around grazing.
But not all forces are exogenous to the pastoral system. In the Borana region of southern Ethiopia, because of indigenous population growth, the number of milk producing cattle per head of the pastoral population is falling. In consequence, the pastoralists face increasing poverty, decreasing food energy levels and greater risk from the effects of drought (Coppock 1996). Furthermore, the larger number of people in the region means that fuelwood is being cut at an ever greater rate. The inevitable result of all these pressures is land degradation. Drought often exacerbates such situations and, indeed, the ability to recover after drought is one of the main indicators of long term environmental and social sustainability of arid grazing systems.
Policy pressures. Several human activities exacerbate the fundamental driving force of increasing population pressure. They are:
"Stabilization" of the system. Often well-intentioned policies sought and still seek to stabilize the "boom and bust" cycles which exist between man, animals and vegetation in arid rangelands. Examples of these are:
Attempts to regulate the stocking rate. This was the main focus of many rangeland development projects in the seventies and early eighties. Development projects promoted individual ranch development, or the allocation of grazing areas to groups, under strict maximum stocking rate obligations. Such attempts failed completely because of the irrelevance of any carrying capacity estimate under variable conditions and because of the difficulty of enforcement (Box 2.3). In addition, these attempts reduced the essential mobility and flexibility of the system, and concentrated stock on limited grazing areas, which may have received little rain.
Feed subsidies for drought relief. Under the argument that it would be necessary to protect national livestock assets, North African and Middle Eastern governments, in particular, have had a policy of subsidizing feed grains as emergency assistance in times of drought. Besides the questionable social effect (subsidized feed tends to benefit wealthier herders only) and the doubtful overall economic benefit, subsidized feed also has a harmful effect on the rangelands. The tendency is for too many animals to be retained on the rangeland, thereby preventing normal regeneration of the vegetation after drought.
Changes in access to land. Traditionally, Muslim land tenure rules favour crop farmers over pastoral herders in access to land because "laying of the hand" (e.g. evidence of use) confers exclusive ownership. This was exacerbated by nationalization of arid rangelands which was introduced by many governments in the postcolonial period in Africa and Asia (IFAD, 1995) and undermined still further the intricate fabric of customary practice. An ecologically well-balanced system of communal land use degenerated into a "free for all" open access system in much of sub-Saharan Africa and India or was replaced by individual farms, such as in Algeria, Botswana and Zimbabwe. Individual farms were too small to permit an efficient use of the erratic rainfall patterns inherent in these areas. In communal areas, the traditional collective internal discipline in the management of the resources disappeared and overgrazing and land degradation followed. Jodha (1992) demonstrated this most convincingly in India (see Box 2.4). The same mistakes are now occurring in the Middle East and are likely in Central Asia. Under the slogan "privatization is desirable", state farms are privatized, the more productive land (and especially the key resources) falls into the hands of the most powerful individuals and sound management of the entire resource base is put in jeopardy.
Box 2.3 Experiences with stocking rate controls.
TO DEVELOP new rnanagement practices for arid rangelands, GTZ sponsored from 1981-1993 a controlled grazing experiment in Senegal, seeking to balance available pasture and stocking rates within a fixed territory in six 200 hectare plots, privatized for the purpose of the experiment. The system was monitored for 12 years for its environmental and socio-economic impact and herd performance, and results were compared with those from herds outside the scheme.
Several problems emerged. First, the constant stocking density proved to be incompatible with the wide variations in rainfall and therefore available forage. In bad years, stocking densities were too high and herds had to be moved out to survive. Available forage was insufficient in three years but under-utilized in four years out of the 12. Only in two years did stocking density actually match carrying capacity. Second, the impact on vegetation was more negative than positive, owing to under-utilization, a decline in quality of pasture, and a thinning out of drought-resistant fodder species. Third, while animal production was good in the best years, animal vulnerability increased in bad years.
with pastoral management practices within and outside the
scheme revealed the superiority of the latter. The
controlled grazing experiment revealed the inherent
limitations of the concept of carrying capacity in an
environment not at equilibrium; the difficulties of
applying a closed model of water and grazing management
on a large scale; the reduction in animal mobility and
flexibility which resulted; and the removal of the
positive symbiotic interaction of animals and plan.
communities. GTZ concluded that efforts to support
pastoralists' self-reliance would have to depend much
more on the creation of a favorable institutional
environment, including securing pastoral land rights, and
access to fall-back areas.
Source: Mearns, 1996, from; Thébaud, Grell and Miehe, 1955.
Box 2.4 Deterioration of the common property resources (CPR) in India.
IN A STUDY of 75 villages in seven rather arid states of India, Jodha (1992) found that the CPR area had declined by as much as 30 to 50 percent between the 1950s and 1982, and there had been a reduction of cattle by 20 percent in favour of small ruminants. The traditional communal management of the CPR had basically broken down:
traditional CPR management shifted to open access,
causing a significant degradation of the CPRs as shown by
the decrease, by about 75 percent, of the number of trees
in the CPR, and the decline in the number of grazing
Source: Jodha, 1992.
Inappropriate incentives. Under a nationalistic strategy of food production self-sufficiency, many governments (especially in North Africa and West Asia), have subsidized tractors and fuel and supported high producer prices for domestic cereal production, further encouraging the encroachment of crops in the "key resource" sites of the arid zones. Many of these areas are marginal for crop cultivation and would not have been cultivated without the subsidies. However, as noted before, these key resource areas constitute the "safety net" for rangeland livestock production and are the key to environmentally sound arid land management. Cheap fuel and trucks have also led to "motorized nomadism" which has allowed the wealthier herders to move their animals rapidly to wherever pasture was available. This has also interfered with the normal regeneration process of the emerging vegetation. Finally, high meat import tariffs also contributed to over stocking.
Response: Technology and policy options
The over-riding need is to stop the building-up of further human pressure in arid zones. As discussed, arid rangelands are already efficiently used and no significant increases in productivity can be envisaged. Since populations in these areas experience a downward spiral of declining livestock/people ratios and increased vulnerability to drought, employment generation outside the dry rangelands is therefore the most critical component of developing sustainable rangeland resource use in the arid zones.
As the second priority, although still of crucial importance, external interventions in the system need to take account of the non-equilibrium status of pastoral systems in arid zones and enhance rather than restrict flexibility and mobility. This means that attempts to regulate stocking rate should be stopped. First, the carrying capacity of rangelands in these non-equilibrium environments cannot be estimated with any acceptable degree of reliability. Second, such estimates can even be dangerous, as they may lead to the wrong intervention in an attempt to control stocking rates (see Box 2.3). Third, even apart from the technical flaws in the estimation of the carrying capacity, experience has shown that it is almost always impossible to enforce stocking rates.
The third priority should be the strengthening of traditional pastoral institutions and resource management practices. "Getting the institutions right", by empowering pastoral people, is now generally considered the main challenge in pastoral and arid land development. Furthermore there has been a growing acknowledgment of the multiple uses that arid rangelands provide to a wide variety of users (IFAD, 1995, de Haan, 1996).
Specific actions to support these strategy elements are to develop effective co-management regimes, forging partnerships between the State and a wide variety of users, with the State carrying the overall responsibility for arbitrating conflicting interests at national level, and facilitating negotiation. Practical management decisions and negotiations between competing users should, however, be delegated to the local level (Mearns, 1996). The delegation of powers would aim to strengthen:
the application of the "subsidiarity" principle (Swift, 1995), within the local administrative capability which requires devolution to local groups of those public administrative powers that undermine or duplicate traditional governance structures. The creation of pastoral associations has already been an important focus of arid land institution building, although results have been mixed (Box 2.5);
customary resource user rights. The need for flexibility and mobility would require the boundaries to be "fuzzy" (Behnke and Kerven, 1994), although with more clearly defined territorial boundaries for the "key resources";
conflict resolution mechanisms, with clear sets of procedural tasks for formal law, and clearer definition of when customary law takes precedence (Swift, 1995).
Box 2.5 Pastoral organizations and arid land management; lessons from the past.
DEVELOPMENT of grassroots, regional national herder
organizations has been a major thrust of most donors in
West and North Africa over the last decade. While there
has been considerable progress in establishing viable
organizations for the provision of services such as
animal health and education, these organizations have,
with some exceptions, such as the World Bank funded
Middle Atlas programme in Morocco, been less successful
in range management (Shanmugaratnam et al., 1992).
They failed to fully facilitate the participatory
process, as they were embedded in authoritarian cultures
of government, project administrations and the social
structure of the groups themselves (Vedeld in de Haan,
1994). Key lessons which emerge from these experiences
are the need to (i) focus attention on procedural law and
conflict resolution rather than on specifying rigid
tenure rights (ii) assume a gradual transfer of
responsibilities to pastoral groups, starting with
services, and progressively moving towards more
sophisticated responsibilities, such as range management;
and (iii) tailor the size of the group to the goals
envisaged. Range management tasks might, for example,
need a different group size than veterinary services.
The fourth priority is the identification of effective drought management policies. Irreversible land degradation in arid zones, if it occurs, originates as a result of high stocking rates during droughts. The appropriate drought strategy is to de-stock as early and rapidly as possible, rather than seeking to maintain maximum stock numbers. Policies and subsequent investments which support such rapid de-stocking are the development of savings and credit schemes, and infrastructure investments in roads, markets, slaughterhouses and cold storage (Pratt et al., in press). However, little experience has been gained of the application of these concepts in dis-equilibrium systems. The only notable exception is Australia.
Incentive policies also play an important role in arriving at sustainable rangeland use. Key elements of appropriate incentive policy would be:
Increasing the costs of grazing in order to reduce animal pressure would promote earlier off-take. The perception of pastoral people keeping livestock for wealth and social status has been abandoned and there is now a general acceptance that pastoralists' behaviour is, as may be expected, economically rational. This economic rationale should induce herders to forsake liveweight gains of their almost mature and only slowly growing animals, and sell them earlier, because the cost of the grazing would outweigh the benefits of the final liveweight gain. But cost recovery has to be combined with a decentralized management of the proceeds by the beneficiaries, to provide appropriate feedback mechanisms to producers and could cover:
Levying grazing fees for communal areas. Such fees have been proposed often but little experience exists of them in practice. A system of progressive fees, with larger herds paying more per head (Narjisse, 1996), is attractive, particularly for many of the dry areas in Africa where livestock are increasingly concentrated in the hands of outside owners, such as civil servants, traders and crop farmers;
Full cost recovery especially for water supply and animal health services. In many cases, water has been a free resource supplied by the public sector (and frequently financed by the international donor community). Full cost recovery, including construction costs, should most likely reduce the number of large boreholes and, therefore, reduce local degradation around these water points;
Removal of price distortions for other agricultural inputs, in order to reduce the conversion of pastoral key resources into marginal crop land.
Most donor agencies now accept these as basic elements of their pastoral strategy as shown, for example, by the excellent recent review by IFAD (1995) of common property resources. In addition, African and Middle Eastern government authorities are increasingly adopting participatory and decentralized approaches, with a greater degree of cost recovery, although considerable apprehension still persists in allowing pastoral groups any great degree of independence.
Research needs. The key areas where future research is urgently needed emerge from the above recommendations. With limited opportunities for increasing production, the emphasis must be on conservation. This implies:
the identification of appropriate indicators to provide reliable information on resource trends in arid areas;
the development of appropriate methodologies for economic appraisal of investment in the conversion of pastoralists' "key resources". These appraisals normally compare only the pasture yield during the dry season or summer grazing, with the cereal yields and, in most cases, the economic benefits from the increased cereal yields outweigh the pastoral use. If the impact of crop encroachment on the entire eco-system is calculated, the use of such high potential areas for livestock is economically more efficient, and certainly environmentally more efficient, than conversion into cropland;
continued research on pastoral institutions;
the design of sustainable drought preparedness plans, with particular emphasis on decentralized management and the design of appropriate banking and insurance schemes; and
the identification of appropriate conflict resolution schemes.
Grazing systems in the semi-arid and sub-humid tropics4
4 Areas with respectively 75-180 and 180-270 days growing season.
Response: Technology and policy options
Although these two zones are combined in this discussion because of their similar physical livestock-environment interactions, many of their agro-ecological and socio-economic conditions are different. The semiarid zones are generally densely populated. Typical areas include parts of the Sahel, the rainfed crop-livestock areas of North Africa, some of the rangelands of Central Asia and the drier areas of the Indian subcontinent. The sub-humid zone savannas have, until recently, been rather sparsely populated because access was impeded by human diseases (such as river blindness, African sleeping sickness) and tick-borne diseases in animals. Typical areas include the savannas of West Africa, eastern Colombia and the Cerrados of Brazil, southern and eastern Africa and eastern areas of the Indian subcontinent. These areas are now becoming the main frontier for agricultural development and worldwide it is where ruminant livestock numbers still grow, as they accommodate, in sub-Saharan Africa an overflow of animals from the drier areas, and, in South America, animals from the Andean Highlands. Livestock interaction involves most components of the environment e.g. land, water and biodiversity.
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