3. Conclusions and Recommendations Relative to LGT-Environment

3.1 Technology/Mitigating Activity

Recent developments in computer-assisted decision support systems (DSS) oriented towards resource management have excellent potential to assist equitable allocation of the grazingland resource to herbivore users. For example, a grazingland DSS (Grazing Land Applications) developed at Texas A&M University acquires inventories of ecological information describing herbivores and grazingland, integrates the ecological information with inventories of economic and social information characterizing the production system, and presents the most ecologically and economically viable stocking rate ensuring sustainable use of the grazingland resource (Stuth et al. 1990).

Applying resource-oriented DSS to grazingland management increases the probability of management based on ecological principles. Rather than engaging in conflict over perceived inequities relative to allocation of grazingland resources, concerned special interest groups should be supporting a systems approach to grazingland management. See also Section IV-3.1.

3.2 Education/Extension

See Section V-3.2.

3.3 Financial Stimulation

See Section III-3.4.

3.4 Land Tenure and Institutional

To enhance human welfare and sustainable resource use, production systems used in an area should be based on their comparative economic advantage (which internalizes all costs, including environmental costs of production) over alternative production systems. Investment in less economically competitive systems encourages poverty among the people with access to the resources in question and reduces incentives for conserving the resource base for production. Since subsidies and taxes distort production profits and therefore incentives to produce, such interventions are to be avoided if they reduce the risk of subsidized but unsustainable resource use.

In areas of low agricultural productivity, conversion of phytomass into livestock products frequently has a comparative economic advantage over alternative forms of landuse. While natural resources, such as timber and wildlife, may represent alternative income sources and should be considered, the infrastructural capital or management skills required to exploit them may not always be available. Assigning rights to fugitive resources, such as wildlife, may also be problematic while ownership of domesticated livestock can be relatively easily defined and enforced. Therefore, the question to be answered is: Where livestock production is economically advantageous, what land tenure systems are suitable, and what institutional adjustments must be made to allow these systems to operate effectively so that this advantage can be realized?

In this report the main types of land tenure and the conditions favoring their applications are summarized. Thereafter, conclusions regarding the institutional adjustments required to enhance the probability of success of appropriate land tenure systems are discussed. Emphasis is placed on internalization of environmental costs, appropriate division of land (particularly in former colonial or socialistic countries), and relationships between public and private land use, e.g., the western U.S.

3.4.1 Types of Land Tenure

Land tenure systems range from open access, with no rights of exclusion, through common property, with a range of institutional arrangements governing the use of resources by individuals in the community, to private tenure, where individual landholders have the exclusive right to determine the resource use. When resources are abundant, the cost of defining and enforcing rights to resources may be more costly than the benefits to be gained from individually owning them. In areas of low population pressure, resources are thus often used communally with varying degrees of individual control over how and when to use them. As human populations grow and demand increases, only well-defined, enforced, and transferable rights to resources will oblige self-interested individuals to face the trade-offs inherent in a world of scarcity (Anderson and Leal 1991).

Without such rights, individuals or communities may not be able to exclude outsiders from using the resources, and they thus attempt to externalize their own costs of exploiting the resources. The net effect is that unowned resources tend to be overexploited, resulting in Hardin's “tragedy of the commons” (Hardin 1968). Thus, sustainable use of resources necessitates clear specification and enforcement of rights to land and its resources when the demand by growing populations exceeds the land's ability to supply the resources being used. The appropriate property rights will depend on a number of factors, including the availability and productivity of land, the availability of labor, and access to capital.

3.4.2 Primary Factors Determining Land Tenure

Productivity of land is determined by climatic factors, especially the amount and distribution of precipitation, and by other environmental factors, including soil fertility, water availability, and plant composition and growth. For example, hot, humid grasslands and open woodlands (e.g., the llanos of northern South America) or temperate grasslands (e.g., North American prairies) often produce sufficiently large quantities of herbaceous biomass to support individual livestock holdings. If soils are sufficiently fertile in these areas, individual landholders with security of land tenure may also produce their own supplemental fodder and other crops. In drier areas with intermittent rainfall (e.g., on the Inner Mongolian grasslands), crop production is constrained by lack of water availability, and landholdings required to sustain livestock productions may be too large for an individual to manage. In such areas communal ownership of land and use of resources have been common.

Availability of labor often determines the extent to which people cooperate or compete in managing their resources. Where labor supply is short because of low population density, labor sharing in a wide range of activities, including herding, is frequently more efficient than individual specialization. This approach tends to favor community cooperation rather than individual competition. Nomadic or seminomadic herding is still practiced in area where people are reliant on livestock and where seasonal shortages of forage force movement of livestock to summer or winter grazing pastures. For example, in Mongolia herders are attempting to reclaim winter grazing areas held by traditional herder groups (consisting of extended families or close friends) prior to collectivization, and they are tending to return to a mixed animal livestock production system to minimize risk in an uncertain production environment (Sheehy and Conner 1993). When population pressure increases, the relative abundance of labor results in a greater degree of specialization and competition and thus privatization of resources and a breakdown of community tenure institutions.

Access to capital is also a major determinant of land tenure. Where capital is readily available for the purchase of land, private land holding prevails. When individuals or communities cannot easily gain credit, private land tenure may not be feasible, and communal land tenure, where the community owns the land de jure or de facto or where it has the usufruct of the land, may prevail. In order to retain people in rural areas, central governments sometimes subsidize capital loans for purchasing land. However, as is evident in the Brazilian Amazonia, this system inevitably leads to distorted land prices and perverse ownership and production patterns when the speculative value of the subsidized land exceeds its productive value (Milikan 1992).

3.4.3 The Effect of Institutions on Land Tenure

Legal and political institutions at the local, national, and international levels may affect the use of resources through their influence on land tenure and the structure of incentives for using resources. Although ocal-level institutions are generally most accountable and sensitive to local interests, they may also be influenced or even controlled by broader national organizations. The extent to which they are supported by local constituents will depend on the extent to which they are able to promote local interests. National institutions generally represent the interests of centralized agencies that are often influenced by special-interest groups, while international institutions frequently attempt to influence national decisions in the interest of influential constituencies of powerful member nations.

States have often assumed control over resources based on the assumption that individuals or communities are incapable of equitably allocating or sustainably using resources. However, once a state has power to enforce actions that would not be voluntarily undertaken, that power is frequently usurped by special-interest groups that are able to influence the political process (Anderson and Leal 1991). Thus, state-run resources, such as rangelands and forest areas, are frequently managed according to the goals of the most influential interest groups.

Government control over resource use and allocation has been far-reaching and has frequently included redistribution of land. Historically, the wealthiest groups of society have been able to persuade politicians to enact subsidies that benefit them. For example, in Amazonia, forest dwellers have been disenfranchised of their rights to permanent occupation of the forests and exclusive use of usufruct of forest resources, allegedly for the sake of resettling rapidly increasing poor urban people (Williams 1983). However, land-clearing subsidies provided by the Brazilian government, and associated rights to minerals in areas adjacent to cleared land, have primarily benefited politically influential livestock owners who, after the land is cleared, consolidate large land-holdings under private ownership (Hecht 1993). Similar land accumulation in Mexico led to the Mexican revolution of 1910, after which the government turned private estates into ejidos on which communities of landless people had usufruct rights (LaBaume and Dahl 1986). The lack of land ownership by these communities, however, led to overexploitation and widespread degradation of grazing resources.

In one of the largest grassland areas of the world in northern China and Mongolia, ideologically driven state intervention in land tenure and agricultural production disrupted traditional, extensive, pastoral production of cattle and sheep (Sheehy and Conner 1993, Simpson and Li 1995). In these areas, all land became state property and state-controlled collectivization of livestock herding attempted to increase livestock production from traditional livestock-grazing practices. It was, however, commonly observed that privately owned animals performed better than those in state or collective ownership (Simpson and Li 1995), and the Research Institute of Animal Husbandry asserts that grazingland associated with the former state farm system is among the more degraded grazingland in Mongolia (Sheehy and Conner 1993). Recent efforts to change subsidized, state-directed farms to semiprivatized agricultural companies will require amalgamation of production areas in some places but have already resulted in a partial return to former livestock production practices.

In the United States the efforts of federal government agencies to manage public land and to influence private use of these lands have led to conflicts as a result of the influence of opposing environmental and livestock interest groups. On the one hand, environmentalists frequently claim that significant portions of federal and state land currently being used under permit to graze livestock exhibit ecosystem disruption and loss of biodiversity, particularly in riparian and upland areas (Gillis 1991, Fleischner 1994). This result has led to siltation of streams and rivers, detrimentally affecting water supplies for major urban centers. Based on these claims, environmental groups are energetically lobbying for the restriction or removal of cattle from public ranges, even when livestock production may have a beneficial ecological role. Many ranchers view any prohibition on grazing as an attack on their traditional resource base and argue that where livestock grazing on public lands has been judicious, range conditions have generally improved since the turn of the century. The inability of the federal government to mediate effectively between these groups and its insensitive enforcement of environmental regulations have resulted in near-revolution by livestock producers in some western states (Kenworthy 1995).

The influence of international institutions on the use of national and local resources has also been ubiquitous. Such organizations, including the World Bank and nongovernment organizations, represent the interests of their primary donors, often to the exclusion of the interests and values of local communities. For example, the World Bank has been a major sponsor of the Brazilian governments program to resettle urban people in cleared forest areas in the state of Rondônia. This program is an attempt to alleviate its social problems resulting from massive urban poverty (Milikan 1992). The World Bank was acting in the interests of its major donors wishing to integrate indigenous peoples into national society. Through its actions it has been held directly responsible for financing a “social and ecological disaster of tremendous dimensions” (Rich 1985).

In all of the examples above, government intervention resulting from the influence of special interest groups or international organizations has led to widespread resource degradation. These situations occur because, whether resources are privately or state-owned, if property regimes are underfunded or managed by distant agents, the fate of resources is inevitably determined by the people living with the resources (Bromley and Cernea 1989). In addition, expropriation of land rights has often set governments against rural people when successful resource management requires the opposite. Thus, where central governments are unable to control the use of expropriated land effectively, previously well-administered resources have often been converted to open-access resources because local individuals and communities no longer have a vested interest in the resources, because they continue to bear the opportunity cost of their existence, and they no longer have the right to exclude outsiders.

These examples are not to suggest that private or communal property rights will produce sustainable use of rangeland resources under any circumstance. Without proper institutional arrangements to internalize the costs of using resources, the benefits of using either private or communal resources can lead to resource degradation. In Brazil large private and corporate ranches exist only because negative real returns to cattle production are overshadowed by the spectacular returns from speculative investments resulting from government subsidies. Similarly, a breakdown in institutions protecting the integrity of the community or those enforcing individual rights to graze their cattle on communal grazinglands inevitably leads to overgrazing. When human populations pressure increases, well-defined, enforced, and transferable rights to resources are increasingly necessary conditions to ensure sustainable use of resources.

3.4.4 Factors Inhibiting Adoption of Effective Land-Tenure Systems

Land-tenure inertia may be caused by a number of factors, including ingrained cultural practices, lack of legislation to enforce land rights, and exogenous coercive forces.

Cultural practices affecting land tenure include the ownership of livestock as a form of investment in the absence of alternative real investment opportunities. In many countries where financial institutions and infrastructure are poorly developed and where land is not individually owned, few alternatives are available for individuals to accumulate personal wealth, other than through investment in livestock. Even when alternative investment opportunities arise, people who have traditionally valued livestock may not widely change their investment base for several reasons. They may not understand the nature of new investment opprotunities, they may not trust the new investments because they have less control over them than over their own livestock, and, under the inflationary pressures that prevail in many developing countries, financial investments tend to decline in value more rapidly than livestock. Moreover, in marginal areas, there may be few if any alternative investment options for rural dwellers, and livestock production is usually less labor intensive and less risky than crop production. Commitment to livestock production may prevent reduction in the area of land used by individuals or communities.

Lack of land-tenure legislation is prevalent in countries that have faced long-term imposition of rigid, centrally controlled systems. For example, in Mongolia transition from subsidized, state-directed agriculture to semiprivate farming is being hampered by difficulties in dividing former state farms into optimally sized production units without the benefit of a promulgated Land Law.

Exogenous coercive forces may be ideological, religious, or political in nature, and, as previously discussed, they may be either nationally or internationally based. For example, in the western United States, land use practices, especially livestock grazing, on both public and private land are being increasingly constrained through the political influence of environmental groups. While coercive measures seldom create positive incentives for conserving resources, they continue to be promoted by agencies sympathetic to the interests of environmental groups. By attempting to impose constraints on commercial land use, such groups effectively impose their values on livestock producers without paying for the costs of such actions to landowners. In other instances, coercive measures have led to restrictions on the commercialization of wild species. These restrictions prevent the development of market structures for affected species, and instead of becoming valuable, their protected existence represents only an opportunity cost for the people who inhabit the land. Such species and the habitats that sustain them are inevitably replaced by production systems for which resources can be used.

3.4.5 Recommendation for Institutional Adjustments

Institutional adjustments required to ensure sustainable use of resources used for livestock production in temperate and humid tropical areas will be area specific. Here three issues will be considered: how to reduce inappropriate land use and overexploitation of resources in developing areas with fragile ecosystems, how to determine the appropriate division of formerly state-owned land, and how to establish a mechanism for internalizing the costs of using public lands.

Land tenure in developing areas has frequently been imposed by central governments, particularly in countries with colonial histories, to achieve agendas for politically influential groups. This situation has often resulted in deleterious environmental impacts, especially on ecologically sensitive areas where imposed land use patterns have substantially modified indigenous biotic composition. Frequently, indigenous people have been deprived of some or most rights to determine the use of the resources provided by the land they occupy.

Resources that may not be used bestow no value but may represent direct costs (e.g., depredation by wild animals) or opportunity costs (e.g., protection of resources, which may preclude the use of land for other activities). Local inhabitants have no incentive to protect such resources and may work actively for their eradication because they are perceived to be a nuisance. Deliberate destruction by central governments of local institutions under which resources were used sustainably in the past leave communities with no vested interest in protecting them unable to exclude outsiders.

In order for rural people to place value on and have a vested interest in the resources that exist on the land they occupy, they must be allowed to take advantage of markets that exist for these resources, and they must be allowed to decide how to use these resources without coercive interference from state agencies or international organizations. This idea implies that they must have security of land tenure, the right to use the resources on their land, and the power to exclude outsiders from using them.

Whether it is most appropriate for land to be privately or communally owned will depend on the inherent fertility of the land, population pressure, the capital available for developing private operations, and the cultural values of the communities concerned. The key issues are that the landholder, whether individual or communal, is clearly defined and that effective institutional mechanisms for enforcing the exclusion of outsiders are in place. This approach enables identification of individuals who may benefit from the resources in question and who are responsible for both the direct and external costs of using these resources. Heritability and alienation rights should also be well specified to protect land from fragmentation and increasing pressure on the land from unchecked growth of the size of community membership. Individual or community autonomy is a necessary condition for providing positive incentives to enhance sustainable resource use, but it may not be sufficient to prevent overexploitation. Accountability for the costs of resource use is equally important. In communal systems, group identity is generally central for individual well-being, and thus in “village economies” there is an interdependence of choice (Runge 1981). In well organized communities there will thus be little incentive for individuals to use resources to the detriment of other present and even future community members. In private land-tenure systems, accountability is equally important. It may be achieved without bureaucratic coercion by making the right to land ownership contingent on levels of resource exploitation sanctioned by the other members of the local community, particularly if they promote ethics based on the idea that “we do not own the land but merely borrow it from our children.”

Institutions that most effectively promote accountability and sustainable resource use in developing areas are those that are accountable to local community members. They inevitably involve community members in decision making and are directed by locally elected leaders, not spokesmen for central government agencies. They also allow community members to benefit directly and equitably from available resources, they promote community identity and allow long-term rights of access to the resources while at the same time restricting fragmentation of the land. Finally, they should facilitate access to enhanced technical skills that enable members to use land more efficiently.

Division of formerly state-owned land among private or communal landholders is frequently complicated by the lack of individual land management skills and entrepreneurial experience of the people inhabiting the land. Thus, the first requirement is to determine the level of such abilities among the inhabitants. Although there may be no recent experience of assuming responsibility for production decisions and land stewardship, there may be historical knowledge of effective land-tenure systems that existed before the land was expropriated by central government. Reversion to such systems may initially be the most natural course of action. As previously indicated, in Mongolia livestock herders are attempting to return to former communal grazing practices by trying to reclaim winter grazing areas held by traditional herder groups prior to collectivization.

However, conflicts arise when there is no promulgated Land Law to control such claims. While former communal boundaries may represent a starting point for laws governing land division, both naturally and state-imposed human population dynamics in the intervening years have disrupted the integrity of former communities. Yet, where the productivity of the land is marginal and best suited to transhumant livestock production, division of land into production units for individual families may result in units that are too small to sustain landholders. This situation is especially problematic in areas where state-subsidized labor has created overemployment.

The development of legislation should be guided by the same criteria previously listed, i.e., clear definition of landholders and land-holdings based on the natural inclination of community members and historical patterns, inclusion of community members and their elected leaders in decision making, community rights to exclude nonmembers from using their land, and mechanisms to prevent fragmentation of land into untenable units. People must also be allowed to establish their own community structures (e.g., historically productive community relationships based on extended family groups) and production systems (e.g., land use patterns such as transhuman-mixed livestock production). It would be erroneous for states to insist on private property rights in an attempt to force people into an accumulative economy based on individual competition rather than community cooperation, as is the case in Brazil.

Centralized state institutions should operate as supportive agencies, rather than coercive policing organizations, to ensure the survival of workable land-tenure systems. While governments must uphold landholders rights to enforce their right to their land, they should also provide training and infrastructural investments. To support livestock production they should enhance institutional capability to assess, monitor and manage the natural resource base needed for livestock production; increase the technical proficiency of institutions associated with livestock production; assist institutions to resolve specific livestock production constraints; and support herder groups to enable individual livestock producers to participate effectively in the market economy.

In addition, it is also imperative that other employment opportunities (e.g., mineral extraction and refinement) be created, especially in areas of high population densities in order to alleviate pressure on the land. Countries such as Mongolia, for example, require the development of transportation infrastructure, which in turn requires massive national and international investment. Finally, in order to reduce livestock pressure on rangelands that results from traditional use of livestock as a store of wealth in many developing countries, governments should facilitate development of alternative reliable and lucrative investment opportunities, education of people to understand them, and a reduction in the riskiness of these investments.

Internalizing the costs of public land use has become a pressing issue in the western United States. While livestock producers are reluctant to give up their rights of access to this source of forage, many environmentalists wish to reserve such land for their wildlife and recreational use. Both sides wish to externalize at least some of the costs of using the resources on this land by allowing taxpayers to pay for the federal costs of administering these lands. In some cases where federal agents have insensitively enforced regulations regarding their use, livestock producers have threatened to reject federal authority over public land. Many environmentalists have been equally belligerent claiming that private use of public resources is inappropriate and ecologically destructive. Federal government agencies continue to perpetuate their jurisdiction over these lands under the pretext that public land cannot be effectively managed as smaller entities and because of the ingrained belief that every U.S. citizen has right of free access to hunt wildlife on public lands.

Yet, there are numerous examples where nongovernment organizations, such as the Nature Conservancy, are effectively preserving wildlife habitat and species on purchased land that was formerly used for commercial livestock production. Conversely, given the opportunity to use wildlife profitably, many livestock ranchers in western states are actively preserving wildlife habitat. However, continued resistance to for-profit use of wildlife is inhibiting such behavior. In order to provide landowners with positive incentives to conserve a broad spectrum of natural resources on their property, markets must be allowed to develop for such resources.

If the full spectrum of resources on western private and public land can be commercially exploited, then public lands could be easily privatized without the risk of losing wildlife habitats. Once such land is available for purchase (with possible constraints on use of critical areas such as riparian zones), private conservation organizations, interested in preserving habitats, as well as livestock producers would be free to acquire the land at the highest bid and manage it for whatever use is desired. If exploitation of wildlife is allowed to be more lucrative than livestock production, it is likely that significant numbers of ranchers would maintain the land as wildlife habitat, and individual parcels of land may well be amalgamated to provide greater ranges for wildlife.

Under such a scenario, landowners would acquire and manage the land without externalizing user costs to the general public. Administrative costs paid by taxpayers would therefore be reduced and, without coercive intervention by state agencies directed by influential interest groups, the current conflict between livestock producers and environmentalists would be diminished. In order to ensure that incentives for production are not being distorted, taxes and subsidies for alternative production systems on these lands must be eliminated.

3.5 Development Projects and Programs

Projects or programs related to the impact of livestock grazing on the environment must evaluate livestock production systems and determine how they influence the ecological health and environmental integrity of grazingland resources. To accomplish this objective, projects will need to determine those systems that are contributing to sustainable use within environmentally acceptable parameters and those that are contributing to degradation. The following outline suggests germane issues that should be considered within such projects.

A. Grazing Management

1. Stocking rate
2. Livestock distribution
3. Kinds/classes of grazing animals
4. Grazing systems

B. Vegetation Manipulation

1. Grazing animals
2. Mechanical
3. Chemical
4. Biological
5. Fire
6. Integrated Brush Management Systems (IBMS)

C. Pest Control

1. Rodents
2. Insects
3. Predators

D. Range Nutrition

1. Nutritional quality of temporal vegetation
2. Livestock nutritional requirements
3. Nutritional mediation/supplementation

E. Marketing Strategies

1. Demand
2. Market availability
3. Transportation/communication
4. Drylot feeding
5. Slaughter/packing/wholesaling/retailing

3.5.1.1 Stocking Rate

Stocking rate, the balance between demand for forage/browse by grazing animals and the supply that grazingland can furnish without degradation of the plant community to a less desirable state, is the single most important principle in grazingland management. Long-term overutilization of forage plants over most of the world's grazingland ecosystems has been the greatest cause of loss of plant cover and the greatest contributor to ecological deterioration through soil erosion and eventual desertification.

Soil loss on a mature grassland ecosystem that has succeeded to the natural potential plant community removes the opportunity to recover the same level of vegetation quantity and quality within time periods that are realistic to society. Soil loss on developing ecosystems arrests primary succession and limits the concomitant progression of plants and soil to the highest level of development within a climatic regime. In both cases the carrying capacity of the land detriorates, reducing animal production and source of wealth to landowners/users.

Since the carrying capacity decline on rangelands is usually subtle, often taking several to many years for perceptible difference, it may act as a motivation for grazingland managers to increase stocking rate in an attempt to sustain income. The obvious result is continuing resource degradation until stocking rates must be reduced in order to salvage animal reproductive performance and production. At this point, the environmental impact from grazing may be substantial, with soil loss contributing to sedimentation in waterways and reservoirs and less stability and drought tolerance in the ecosystem. Loss of grazing-animal production has ramifications on both individual land managers and the communities and supporting industries that service them.

Evaluating grazingland landscapes to determine a rate of stocking that will stop retrogression and restore the plant community through secondary succession to a more productive and protective state should be a first-priority project. In many rangeland ecosystems, remnant plant species from the climax vegetation can be managed by manipulation of grazing animals so that they increase in relative proportion in the vegetation composition. Such ecosystems are characterized as having a high successional response potential. It may even be possible for these plants to regain dominance within the plant community.

Manipulation of vegetation with grazing animals can be accomplished by controlling the frequency and intensity of grazing utilization (defoliation) of the plant species most desirable in the plant community (key species). While the kind of grazing animals used, time of grazing, and distribution of grazing are all significant factors in attaining proper grazing use of rangeland vegetation, the stocking rate, animals per unit of land area, is the most important. To understand the need for proper stocking rates, grazers must understand the fundamentals of range plant physiology and morphology. In simplest terms, grazers must understand how plants grow and how defoliation impacts their ability to reproduce and remain vigorous and competitive with less desirable plants in the rangeland environment. Any project that deals with stocking rates must begin with the impact of grazing on plants.

Teaching these principles in certain societies within developing countries may require innovative, nontraditional methods; however, it is not impossible. The principles and processes involved in the relationships between grazing animals and plants can be effectively taught in almost any environment involving grazingland and the plant/animal/human interaction. Teaching may even include the use of computerized technology in some instances (Hamilton and Sheehy 1993). A greater problem is getting application of the principles of proper rangeland use, even after there is an understanding and apparent acceptance of the principles. Developing the motivation among grazers to actually reduce livestock numbers, and perhaps income, in the short-term for the sake of future increases in production is very difficult. The problem is magnified in the more arid regions by the slow rate of change that takes place in plant composition, often imperceptible for several years, whether driven by proper or improper stocking in relation to forage supply. To many grazers the dramatic increase in rangeland production caused by one or more years of above-average precipitation indicates that their stocking rate is not a problem; production is strictly a function of rainfall. Moreover, in some societies, reducing stocking rate has a profound impact on the total wealth and social standing of grazers.

Even in view of the well-documented problems in gaining acceptance and application of the principles of proper range utilization, and proper stocking rate in particular, there must be a project to address this issue. The project must involve not only the grazers within the population but the bureaucratic infrastructure and administrative authority within the society (Hamilton and Sheehy 1993). It is very likely that incentives will need to be provided in the short- to midterm in order to accomplish significant stocking rate adjustments. The key elements to success of sustainable grazingland systems are education, motivation, and application at every level within the system, from the government to the individual grazer, beginning with an understanding of how plants grow and the relationship of grazing animals to the health of individual plants and of rangeland in general, a function of stocking rate.

3.5.1.2 Grazing Distribution

Even when stocking rates are appropriate for landscapes, gross overutilization of forage/browse can occur because of concentrations of animals. Such concentrations can be the function of grazing animal preference for different plant communities (range sites), topographic restrictions/preferences, environmental amenities (shade, etc.), climate (prevailing wind), and/or distance from water. Conversely, poor livestock distribution can result in underutilization of forage resources in those areas less occupied by animals. The loss to the livestock production system is twofold. First, the areas that are heavily overused decline in range condition and may even become nonproductive eroded sites, thus representing a loss to both the landowner/operator and society. Those areas that are underused represent forage loss that could have contributed to income, representing a loss to the landowner/operator. Grazing distribution, the effects and how to overcome it, should be a part of any project dealing with grazing management.

In sedentary grazingland systems, grazing distribution is largely a function of manipulation of animals with fencing, water locations, mechanical abridgment of topographic or vegetation constraints, and management-unit configuration. In transhumant systems, grazing distribution is often less of a problem, except as it relates to availability of water resources. In the latter instance, development of additional water locations for livestock on formerly unused or underused areas of grazingland has often contributed to overuse and degradation rather than to the benefits of good grazing distribution. Grazers often overuse the new forage resources made available by additional water supply to the same degree as those to which they were previously limited. Thus, livestock production system enhancements that include added water contribute to general rangeland deterioration. The obvious reason for this phenomenon is that there is no understanding of, appreciation for, or motivation to apply the principles of proper range use, beginning with proper stocking rate. Therefore, grazing distribution must be considered an integral part of any project dealing with grazing management and vice versa.

Landscapes can be inventoried to evaluate the potential for forage loss caused by poor grazing distribution. Inventorying can be accomplished by creating polygons that represent areas of diverse selection by, or limited access to, grazing animals (Stuth 1991). A common method is to overlay maps of the landscape with layers representing distances from existing water, topographic restrictions, heavy brush cover, etc. The forage resources within each of these polygons is assigned a percentage representing that part of potential forage that is actually available to grazing animals. The stocking rate for the entire landscape is then reduced by the difference between potential and available forage. This method relieves the grazing pressure on those areas subject to the most damaging degree of utilization.

The process of inventorying grazingland landscapes to determine distribution constraints also allows economic analysis of improvements to improve distribution. The reduction in stocking rate, expressed as numbers of grazing animals caused by poor distribution, can represent the potential increase in animals that can be obtained with appropriate improvements. The amortized cost of improvements can be compared to the benefits from increased production in the new system to arrive at an estimate of economic feasibility.

3.5.1.3 Kinds/Classes of Grazing Animals

Any project on grazing management must also include consideration of the kinds and/or classes of animals exposed to a grazing landscape. One obvious reason for such consideration is the relative availability of forage in relation to the preference and ability of grazing animals to utilize the forage supply. For example, areas of grazinglands that have a high ratio of shrubs to herbaceous plant species will lend themselves to use by goats as opposed to cattle or sheep. Conversely, cattle will utilize a very high percentage of herbaceous plants, primarily grasses, in their diets. Sheep are known to prefer a higher percentage of forbs (broadleaf, herbaceous plants). There is a tendency for the different kinds of animals to be drawn to those areas presenting the preferred diet composition (Heitschmidt and Taylor 1991).

Cattle tend to prefer level topography generally associated with valleys or gently sloping lands in foothill areas. Goats will make good use of steep slopes and terrain too difficult for cattle. Sheep may use areas on top of ridges not frequented by the other two kinds of animals. These differences mean that combination stocking offers more opportunity for better overall rangeland use where there are a variety of vegetation types (range sites) and topography.

Balancing the kind of grazing animals with the vegetation composition is often economically superior to stocking with a single kind. For example, in the Edwards Plateau of Texas, the combination of cattle, sheep, and goats is usually economically superior to single animal stocking. However, recent removal of federally funded wool and mohair incentives may impact the economic aspects of combination stocking.

Combination stocking tends to equalize the stress of defoliation across all plant components on the range, thus reducing the competitive advantage of any one. This method has resulted in significantly increased stocking rates in some plant communities where vegetation components provide the primary preference for more than one kind of grazing animal. Major limitations to the use of combination stocking in areas where it has no history include lack of markets (increased transportation costs), lack of management expertise, a requirement for large capital investments in fencing and facilities (wool/mohair shearing and shedding facilities), predation (predator control), and competition with income-producing wildlife species (especially between white-tailed deer and goats). However, grazing management projects should include a comprehensive study of the history of grazing use and studies to investigate any stocking rate synergism and potential economic advantages associated with changing the kinds of livestock or using combinations of more than one kind.

Different classes of animals within the same kind - for example, steers as opposed to cows - can play a significant role in grazing management. In the U.S., nonbreeding animals stocked on the range for the purpose of selling their increase in weight are usually kept for periods of less than a year. The period of time between the sale of one group and receipt of the next group of these stocker animals allows the opportunity for effective range deferment. In developing areas, such as North China, these nonbreeding animals may be kept in the herd for several years, thus negating the opportunity for significant deferment associated with their ingress and egress in the system. A grazing management project should study the potential for modification of such systems (markets, transportation, etc.) as a means to make possible and encourage reduced stocking rates and deferment periods.

3.5.1.4 Grazing Systems

Assuming a correct stocking rate, grazing systems provide for deferment periods that encourage establishment, reproduction, and recovery of vigor among the key plant species. This provision usually results in improvement of range hydrologic characteristics, ecological condition, and, generally, an increase in quality and quantity of forage produced. Grazing management projects should evaluate potential for use of systematic grazing as a means of arresting rangeland degradation and promoting secondary succession.

For the purposes of this work, it is practical to define two general classifications of grazing systems. Those systems that have one-half or more of the land area within the system being grazed at one time and that have longer grazing periods than rest periods are classified as deferred rotation (also referred to as rotation-deferred) grazing systems. Conversely, those systems that have less than one-half of the land area grazed at one time and that have longer rest periods than grazing periods are classified as short-duration grazing systems. Heitschmidt and Taylor (1991) state that functionally there are four basic types of systems: deferred rotation; rest rotation; high intensity, low frequency; and short duration. Within each of these classifications, there are numerous variations. For example, a 3-pasture, 2-herd system with 6 months grazing and 3 months rest provides an effective rotation of the deferment period and requires the movement of only 1 herd every 3 months. A 4-pasture, 3-herd system with 12 months grazing and 4 months rest provides a rotation of the deferment period so that the same pasture is grazed at the same season of the year only once within 4 years. This system requires movement of only 1 herd of livestock every 4 months.

Deferred rotation systems are relatively easy to accommodate on many rangeland units where the carrying capacity of the pastures involved vary no more than about 10 percent. Deferred rotation grazing systems have shown to produce slow, steady range condition improvement, good individual animal performance, and requirements for relatively low levels of management input to conduct successfully.

Short-duration grazing involves systems that normally utilize one herd of livestock moved through several pastures. Short-duration grazing systems that utilize long rest periods and long grazing periods are referred to as high intensity, low frequency systems or extensive short-duration grazing systems. Systems common to this subclass often have 5 to 7 pastures, with 3 to 4 weeks grazing and 3- to 6-month rest periods. These systems have consistently promoted rapid recovery of range condition as a function of the long rest periods. However, they do not usually favor individual animal performance, especially if long grazing and rest periods force animals to graze less desirable forage before moving, and they are then presented with high ratios of moribund to live forage in the new pasture. Such systems are, however, excellent for the incorporation of range improvement practices. They are flexible enough to allow skipping over one or more pastures for treatment applications and pre- or post-treatment deferment periods without disrupting the entire system. Moreover, the pastures within the system do not need to be equal in carrying capacity, since time of grazing with one herd can be fit to each individual pasture in the rotation.

The intensive rotation systems within short-duration grazing are those in which the time of grazing and rest are short. Pasture numbers within this subgroup are usually 8 to 15 or greater. Typical systems within this subgroup feature 3- to 5-day graze periods and 40 to 75 days rest. The short grazing periods allow livestock selectivity of the forage offering and optimizes forage quality. The short rest periods reduce the dead-to-live ratio presented to grazing animals in the new pastures. These systems are often capital intensive to construct and can intensify management requirements. Some have shown apparently sustainable increases in stocking rates from those recommended for extensive systems. The majority of the increase may come from improved distribution of grazing associated with the cartwheel, or central hub and radiating pasture fencing, design used to facilitate livestock movement. There may be some increase in stocking rate associated with an improvement in harvest efficiency in the most intensive of these systems (rest periods of 30-60 days). Range condition improvement is generally a function of stocking rate, although most systems documented through research in Texas have not shown the capacity for significant improvement.

There are other alternatives to the use of calendar-based grazing systems and those which require high cost of construction. Decision deferments, where the land manager decides to remove livestock grazing from an area to provide rest and recovery, can be effective. To make decision deferment work, however, livestock must be accommodated on other areas that will not be abusively overgrazed by the addition of increased animal numbers. Decision deferment can be done by not stocking a portion of the total unit so as to always have a forage supply available to accommodate deferment, placing animals in temporary drylot, or using off-ranch forage resources.

There are other methods of moving livestock to provide rest periods, such as the best-pasture method used in arid zones of the western U.S. This method is based on seasonal suitablity and moves livestock to areas of the range that have received the latest precipitation, thus presenting the highest quality of forage to animals while resting drier areas (Holechek et al. 1989). Such systems are applicable in large-scale units where the distribution of precipitation is frequently unequal because of distance between pastures and the isolated nature of convection storms in the region. Livestock systems that include herding of animals on open range use a best-area approach that accomplishes the same objective.

Grazing management projects should include studies of the potential for use of systematic grazing as a means to improve range condition. In lieu of the capability of land managers to install formal grazing systems, seasonal rotations, best-pasture/-area, or other decision deferment methods should be considered.

3.5.2 Vegetation Manipulation

Authorities agree that there have been dramatic changes in the composition of vegetation on many or the world's rangelands. In many areas, these changes have been associated with human activities. Scifres and Hamilton (1993) listed the following causes for shift in the composition of South Texas vegetation from primarily a savannah aspect to closed thorn shrublands: a) long-term overgrazing, b) suppression or elimination of significant naturally occurring fires, c) human mobility that facilitated the spread of woody plant propagules, d) cultivation and abandonment of rangeland soils, e) introduction of alien species with no natural enemies, f) fencing of livestock that restricted their natural movements away from overused areas, g) an increase in atmospheric carbon dioxide that is an advantage for C3 plants (including woody plants) versus C4 plants (warm season perennial grasses). These agents of change would not be dissimilar from other areas of the world where shrubs tend to dominate once they escape from a graminoid succession.

While most human activities related to shifts in range vegetation composition need no further explanation, the effect of elevated carbon dioxide in the atmosphere on plant growth is a relatively new hypothesis. Mayeaux et al. (1991) show that there has been an approximate 30 percent increase in carbon dioxide content of the earth's atmosphere within the last 125 years (from approximately 265 ppm to 350 ppm at present). Plants with different carbon pathways, C₃ versus C₄ plants, are differentially advantaged by the enriched carbon availability. Cool-season plants and woody plants that have C₃ pathways tend to have greater net photosynthetic rates and are expected to have greater biomass increases than C₄ species in response to elevated CO₂. These increases will theoretically lead to an increase in the relative composition of shrubs versus warm-season grasses and compound the problem of reduced herbage production.

There is an ideal or best mix of vegetation to meet any management objective for the use of rangeland. In many cases, this mix will be the one that provides the greatest level of forage production for livestock. In other cases it may be a vegetation composition that provides the best wildlife habitat or recreational use. Often, there is the desire for an optimum combination of plants to accomplish multiple-use objectives. In all instances, protection of the soil and sustainability of the resource must be addressed.

Several methods are available to manipulate rangeland vegetation to accomplish management goals. The foremost methods is the use of grazing animals. Grazing animals are a biological method of manipulating vegetation; however, the use of insects, fungi, or pathogens are additional biological applications for brush and weed control. Other methods include mechanical, chemical, and prescribed fire.

Weed infestations in some rangeland areas present critical problems to landowners or land management agencies. For example, estimates indicate that 2,300 acres a day of U.S. public lands managed by the Bureau of Land Management are being lost to noxious weeds. Leafy spurge (Euphorbia esula) infestations in North Dakota were estimated to have cost the state $75,000,000 in total reduced business activities for all sectors in 1989 (Bureau of Land Management 1994, Leistritz et al. 1992). The reality of livestock and forage losses and negative economic consequences from alien and domestic weed infestations on rangelands points to the need for projects and programs that elucidate the role of management systems.

3.5.2.1 Grazing Animals

Native grazing animals were a part of the ecological processes that formed the natural potential vegetation communities of the world's grasslands during primary succession. Native and domestic animals continue to have profound influences on plant communities by promoting retrogression or facilitating secondary succession. Typical overutilization of the aboveground biomass of the preferred plant species by domestic livestock or combinations of domestic and native animals causes reductions of these plants in the composition of communities. A classic example of the process of retrogression can be found in the American subhumid lands, where tallgrass prairie species give way to mid- and shortgrass species following long-term overgrazing. In the Tamaulipan Biotic Province, there is overwhelming evidence that native woody plants (often Type II increasers) have dramatically increased in both range and density as a result of several factors, not the least of which is long-term overgrazing.

Rangelands of the world support heterogeneous plant populations, including grasses, sedges, rushes, forbs, shrubs, trees, and cacti. Different animal grazers/browsers have inherent preferences for different plants and can be used to target the intensity of defoliation on a particular kind of vegetation. Combinations of animals can be used to optimize the efficiency of harvest and make better use of grazinglands that offer a variety of plant types. Moreover, grazing animals can be used to suppress the population of certain plants and allow concomitant increases in others that are considered more desirable. Therefore, projects are needed to elucidate the potential of grazing animals to manipulate vegetation toward a best mix of plants to meet management objectives for sustainable production.

3.5.2.2 Mechanical

Vegetation can be effectively manipulated with the use of mechanical equipment. This method has several advantages, including soil modification for seedbed preparation and environmental safety. There are basically two categories of mechanical brush and weed management practices, those that remove only the aerial portions of treated plants (simple top removal) and those that remove the entire plant (complete plant removal). A disadvantage of many mechanical brush and weed management practices, particularly in developing countries, is that they are capital intensive. There are, however, manually applied practices that have great success for relatively low plant densities. For example, research in Texas has shown that 434 small juniper plants/acre could be hand-grubbed for a total cost of $6.18/acre. The cost/density range in the study was $3.65/acre for 170 juniper/acre to $9.00/acre for 660 junipers/acre. These demonstrated costs associated with individual plant treatments of low-density infestations make this an economically feasible treatment alternative for developing, as well as developed, countries.

A key factor in the selection of mechanical practices is the growth habit of the target and associated plant species. Many woody plants on rangelands have the ability to resprout vigorously following simple top removal. Meristematic tissue at the stem base, the root crown, or on the roots is stimulated when apical dominance is broken. The regrowth from these plants may present equally severe problems to the original brush stand or, in some cases, dramatically worse problems. However, the use of simple top removal in conjunction with other treatments in the planning context of integrated brush management systems (IBMS) continues to make them a viable option. For example, top-removal practices on resprouting species can be followed with goating and/or prescribed fire.

The regrowth from woody plants that have become decadent and above the browsing height for animals is not only more accessible but more acceptable (palatable) and, in some cases, more nutritious. While fire will not cause mortality of resprouting woody plants, periodic burning will suppress regrowth and permit herbaceous forage production to increase. Simple top-removal practices can provide soil surface modification for seedbed preparation (roller chopping), or they may not be effective for seedbed preparation (shredding).

Complete plant removal practices are generally more energy- and capital-intensive than simple top removal, but they result in high levels of target plant mortality. Broadcast methods, such as rootplowing, are effective for control of mixed stands of problem plant species. Individual plant treatments, such as grubbing, allow selectivity of control. Several practices that can provide complete plant removal, such as chaining, cabling or bulldozing, may also provide only top removal or a combination of complete plant and top removal depending on size of target plants, soil moisture, and texture.

Projects to evaluate the application of mechanical technologies to manipulate rangeland vegetation should be considered.

3.5.2.3 Chemical

The use of chemical brush and weed control technology to manipulate rangeland vegetation is a common practice in developed countries. It has less application in developing countries where the infrastructure required for efficient, large-scale applications is not in place and because it may be cost prohibitive. Still, the use of chemical methodologies for suppressing undesirable vegetation in order to maintain or regain dominance by preferred plant species holds potential. This method of brush and weed control should be studied as a part of projects dealing with the interface between grazing animals and the rangeland environment.

Since the discovery of the growth regulating properties of the phenoxyacetic acids 2,4-D and 2,4,5-T in the early 1940s, there has been a modest proliferation of primarily growth-regulating compounds for use in brush and weed control. The early compounds, as well as the more recent discoveries, have three notable properties: a) they are highly selective, providing effective control for broadleaf weeds and brush species without damaging desirable grasses; b) they are systemic in action, absorbed by plants and moved internally to a site of action where they disrupt vital physiological processes; and c) only small amounts are required for weed control (Scifres 1980).

Chemicals labeled for brush and weed control on rangeland and commonly used within the U.S. include those classified as benzoics (dicamba), bipyridiliums (paraquat), phenoxys (2,4-D), ureas (tebuthiuron), pyridinecarboxylic acids (picloram, triclopyr), sulfonylureas (metsulfuron), and triazines (hexazinone). These chemicals have modes of action that cause target plant mortality by interfering with myriad plant physiological processes (phenoxys, benzoics, pyridines) and interfering with photosynthesis (tebuthiuron) and inhibition of cell division (metsulfuron). Paraquat is a contact herbicide.

The recommended application rate for the foliar applied, auxin-type herbicides is commonly 0.5 pound of acid equivalent per acre (0.6 kg/ha) or less. Some of the more recent herbicides approved for rangeland use, such as mesulfuron, require as little as 0.05 to 2.0 ounces of active ingredient per acre (.004 to.15 kg/ha). These low rates make the chemicals logistically efficient to transport, handle, and apply to large areas. Aerial application of foliar-applied herbicides can cover large acreage in a short time period. There is usually little damage to associated, nontarget woody vegetation. Improved application techniques and drift-control agents (additives) greatly reduce the danger of contamination of nontarget vegetation.

The Rio Grande Plains of South Texas is an example of a Major Land Resource Area with a significant brush and weed problem. South Texas has similarities to areas in Mexico, South America, Africa and Australia. There is a threshold associated with the degradation of rangeland as it moves from a graminoid domain with a grass-driven succession to a shrubland domain with succession driven by woody plants (Archer et al. 1988). The threshold is the point past which significant secondary succession cannot be accomplished with grazing management only. Brush control practices are needed in order to make possible moving back across the threshold into the graminoid domain within a foreseeable planning horizon. In other areas, perennial or annual weeds may be problems that are as significant as woody plants. When the level of infestation and persistence of weedy plants cannot be managed with grazing management decisions, the use of herbicides or other control technologies may be justified. Control technologies may be the only feasible alternative for arresting degradation and beginning the process of secondary succession.

Herbicides are applied to the foliage of target plants as liquid sprays using either ground-based equipment or aircraft. Aircraft are most practical for rangeland applications because of the restrictions to ground equipment from terrain, stature of woody plants, and the scale of the area to be treated. Soil-applied herbicides, such as tebuthiuron, may also be applied aerially or with ground equipment. Individual plant or spot treatments provide an alternative to broadcast treatments when density of the target species makes this method more economically feasible. Application methods for individual plant treatments include foliar sprays, basal treatments, and soil applications of the herbicide. In many rangeland areas, the density of undesirable plants is low enough to justify individual plant treatments. Densities of less than 200 to 400 plants per acre are generally considered potential sites for this method (Hamilton et al. 1993).

Individual treatments are highly effective compared to most broadcast applications, present less possibility of environmental risk, and can be performed with unskilled labor and low equipment investments. A mixture of diesel oil or water and the herbicide is commonly used for individual plant treatments, applied either to the foliage or to the plant base. Hexazinone is currently used primarily as a soil-applied liquid herbicide for treatment of individual plants with an exact-dose, spot-gun applicator.

Many rangeland areas of the world have populations of weeds that can be effectively controlled with herbicide applications. While there are environmental concerns associated with the release of chemicals in the atmosphere and the prohibiitve cost for some areas, they merit attention in rangeland projects. The use of herbicides in conjunction with other technologies as a part of integrated brush management systems provides the greatest opportunity for biologically and economically efficient results.

3.5.2.4 Biological

Biological control is ideally suited to control rangeland weeds and brush infestations of which the major weed pests are perennial, growing in a relatively undisturbed habitat and in areas where the low economic return per unit area makes chemical and mechanical controls expensive (De Loach 1980). Vegetation manipulation with grazing animals has been discussed previously; however, there are other biological agents that must be considered in projects involved with environmental impacts of grazing.

Two basic methods of biological control are available: a) introduction of foreign organisms not already present and b) augmentation of the effectiveness of organisms already present. The first method is the more suitable one for use on rangelands because it is usually much cheaper. The controlling organisms are released in the field at a few sites, then they multiply and disperse on their own over the entire infested area, providing permanent control. A disadvantage is that the organisms will probably attack the target weed wherever it grows, including environments where it may be beneficial. For example, range livestock producers in South Texas consider pricklypear valuable for drought emergency livestock feed, whereas sheep producers in the adjacent Edwards Plateau consider it a major pest species.

Augmentation is usually too expensive for use in low-value per acre/hectare agricultural systems such as rangelands. The control (mass rearing and release of insects or pathogens, spread from areas of surplus, etc.) must be applied to all parts of the infested area, often yearly or more frequently. Such methods are unlikely to be economical where 20 to 50 acres (8 to 20 ha) must be treated to produce one animal unit. However, this method has the advantage that it can be applied only to areas where control is wanted so that plants with beneficial value will not be harmed. Also, the control can be discontinued at will simply by stopping the treatments.

According to De Loach (1980), successful biological control program of either native of introduced weeds by the introduction of foreign control agents, the following conditions must be met:

a. Natural enemies must exist somewhere in the world that do not occur where control is desired and that could be introduced. This means that the weed species or at least other species in the same genus as the weed species must occur in other areas, and preferably they should be native there so that host-specific enemies have had time to evolve.

b. The target weed should have no substantial beneficial value, and in practice, the expected gains should be much greater than the expected losses before control is considered.

c. Species closely related to the target weed should have no substantial direct beneficial value to humans nor substantial values to the ecology within the area of distribution. Highly specific organisms can sometimes be found that do not harm even closely related plant species, but the chances of finding effective control agents are greater if host specificity is not required.

The ecological impact of controlling an introduced weed, aside from the effects on any direct beneficial uses by humans, usually can be considered to be of little harm and probably of great benefit. Since the weed is not a natural part of the ecosystem, its removal should have little negative effect. Native plants, however, are closely interwoven into the plant and animal communities and are of varying importance in the food chain. A great reduction in abundance of these weeds may affect some of the other species. However, a reduction may also be of benefit in the ecosystem if the weed has increased greatly and has upset the natural balance in the plant and animal communities (De Loach 1976).

Success potential for biological control depends upon whether effective and safe control agents can be found and introduced. The site of origin and world distribution of the weed species and genus will indicate where natural enemies might be found and whether the search can be on native weed species, with an assurance that the control agent will attack the target weed species, or whether other species of the same genus must be examined, with the attendant lesser chance of its effectively controlling the target pest or of being sufficiently host specific to introduce safely.

The classical success of biological control of pricklypear (Opuntia sp.) in Australia through introduction of the moth, Cactoblastis cactorum, imported from Argentina points to the great potential for the use of this method. Within the U.S., klamathweed (Hypericum perforatum) was successfully controlled on five million acres by introduced beetles, mainly Chrysolina quadrigemina. Worldwide there have been about thirty instances of successful biological weed control. Where it is successful, there is no method that offers greater return on investment than biological control. Even if it is only partially effective, it can become part of an integrated control program. Therefore, this method should be given priority consideration in rangeland projects that consider vegetation manipulation.

3.5.2.5 Prescribed Fire

Fire is a component of grassland ecology in all parts of the world. Anywhere that vegetation grows in close proximity the potential for conflagrations exists. Fires were a part of the natural processes that maintained the dominance of herbaceous vegetation in natural savannahs and grasslands by suppressing encroaching shrubs and trees. Several factors associated with the increasing sedentary nature of humans has caused great change in grassland ecosystems, not the least of which are reduction of fuel load (amount) and continuity (proximity of fuel particles) and a desire to suppress fires (Scifres and Hamilton 1993).

Modern humans' resistance to the use of fire for natural resource management is only recently changing. Foresters now recognize the value of prescribed burns to reduce the chance of wildfire as well as to create subclimax vegetation associations that favor upland game species. Overmature or decadent, closed overstories of trees often become biological deserts for flora and fauna that require access to sunlight and reduced competition. Shrublands provide the same limitations as mottes of shrubs coalesce into continuous canopy covers of woody plants. In these instances, herbage or browse are either nonexistent or inaccessible. Fire can be used to cause mortality of woody plants or, more generally, cause top-kill of the aboveground biomass. This releases a ground layer of vegetation, including so-called fire-follower species, often high quality legumes, that need fire prior to germination. In forest ecosystems, regrowth from several shrub species following fire can create enhanced habitat for deer, elk, and other upland species.

While humans' use of fire for manipulating vegetation is an ancient practice, modern, sedentary humans learned to fear the destructiveness of wildfires and developed a negative view of the use of fire in natural resource management. However, prescribed burning is now an accepted method in parts of the world where it was unacceptable on many rangeland resources just twenty to thirty years ago. The increased interest in fire for grassland vegetation management can be traced in large part to a) the increased cost of alternative brush and weed control methods, b) elucidation of the benefits that can be obtained through the use of fire, c) development, publication, and instruction in fire behavior, d) development of protocols for prescription burning and the use of fire plans that provide adequate safety, and e) demonstrations that show successful use of fire.

Prescribed fire is usually less expensive than other methods for manipulating rangeland vegetation. Therefore, it has merit as part of a project to study the relationships between grazing animals and the environment. This would be particularly true in areas of the world where available capital for other methods of brush and weed management is scarce.

There are several accepted purposes for prescribed fire in rangeland ecosystems. Fire can be used to suppress woody plants or weeds that are encroaching into desirable herbaceous vegetation. Burning can improve the accessibility, acceptability, and nutritional quality of vegetation (Scifres and Hamilton 1993). The use of fire to top-kill woody plants and cause coppice from the base by tender, nutritious shoots has great application for improving grazing quality, particularly where goats or other browsing animals are used. The same positive influence on browse quality can be significant to wildlife, such as deer, elk, and other upland species. In the case of a woody plant species that does not have the capacity to resprout from buds below the level of the bottom limb, such as Juniperus ashei, fire will cause mortality of exposed plants, depending on the size of plants, fuel load and continuity, and the environmental conditions associated with the burn.

Fire can be used to remove “rough” vegetation and increase the acceptability of biomass from the same plant species. Two examples of this approach are Spartina spartinae, Gulf cordgrass, and alkali sacaton, Sporobolus airoides. These plants and others like them in grassland ecosystems become rank and relatively unpalatable without the use of fire to remove the moribund parts and expose fresh, new growth to grazing animals. Ranchers in South Texas have used fire for the management of gulf cordgrass as a routine practice for over a century. In west Texas, the burning of alkali sacaton and tobosagrass to improve palatability is now an acceptable practice. Fire favors some herbaceous plant species over others, thus, making it possible to use fire to manipulate the relative composition of rangeland vegetation. For example, in the subhumid lands of the continental U.S., the tallgrass prairie, the four dominant tallgrass species, Big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), yellow indiangrass (Sorghastrum nutans), and switchgrass (Panicum virgatum,) are favored by spring burning compared to cool-season species, such as Canada wildrye (Elymus canadensis). Fire can be prescribed in order to cause the shifts desired by management. There are other results in the literature of the use of fire to shift vegetation composition. In South Texas, a very desirable perennial forb, Desmanthus velutinus, has been shown to increase dramatically following burning. Holechek et al. (1989) suggested additional objectives for the use of prescribed burning, including improved visibility after prescribed burning of certain kinds of range, especially piñon-juniper, chaparral, and desert shrub types, reduced labor costs of handling cattle and horses, and reduced predation due to better visibility of sheep.

Like many other practices for the manipulation of rangeland vegetation, fire rarely is a stand-alone method. There must be sufficient fuel load and continuity to carry a fire and accomplish the designed objectives for a burn. Areas that have been heavily overgrazed most often lack fuel beds that make fire a realistic alternative. In such cases, a pretreatment is usually required. This may simply be deferment from grazing for the time required to build adequate fuel load and continuity. In other cases, a pretreatment of alternate technology, such as a mechanical or chemical practice, may be necessary. It has been well stated that in many rangeland ecosystems fire is best viewed as “hamburger helper,” that is, it makes something more expensive go further and have better end results (Scifres and Hamilton 1993).

The desire to reduce risk of wildfire and to burn under conditions conducive to a gentle, controllable fire front, makes cool-season burns generally preferred. These fires are referred to as maintenance burns, those that will promote the maintenance of a dominant species or plant community making up the fuel bed. Such fires can accomplish many of the purposes for the use of burning, but they may come up short of doing the required degree of damage to encroaching woody plants, particularly when fuel beds are marginal. This situation requires the use of reclamation burns that will generate enough heat to do significant damage to the encroaching plants. In order to accomplish this objective, such burns may need to be installed under harsh, highly combustible circumstances. This would include relatively (compared to maintenance burns) high air temperatures, low relative humidity and low fuel-moisture content, and high wind velocity. Such fires would be comparatively dangerous and hard to control as wildfires and should be avoided unless no alternative exists.

In developed countries the use of fire in natural ecosystems has some negative aspects, including the risk of wildfire and subsequent damage to humans, animals, property, and the environment. It is anticipated that there will be a growing concern over the level of particulate matter released into the air from rangeland burning. While environmental concerns may not be significant in developing countries, the risk of physical damage from wildfire is universal. Still, the potential benefits, and more importantly the cost-benefit ratio, associated with prescribed fire cannot be overlooked in the development of projects that deal with livestock grazing and the environment.

3.5.2.6 Integrated Brush Management Systems (IBMS)

Integrated brush management systems (IBMS) offer the possibility to develop rangeland vegetation improvement strategies that include all components of enterprise operations and, thus, to optimize the entire system. The definitive work on IBMS was done in the early 1980s and published in 1985 (Scifres et al. 1985). A model has been developed that describes the protocol for development of a system, beginning with the setting of enterprise objectives, a comprehensive inventory of natural and physical resources, identification of problems constraining the accomplishment of objectives, matching the problems with appropriate technologies, analyzing the alternatives for relative economic feasibility, selecting and implementing a plan, monitoring the results, and feeding real-time data from the application back into the planning process.

In any rangeland environment where vegetation manipulation is being considered, IBMS should be used. The system requires viewing brush and weed management, or the manipulation of vegetation through secondary succession with grazing animals, in a strategic view - that is, using planning horizons that are long enough to allow the biological implications of improvement practices to have economical viability. All strategies considered in the planning process are subjected to the reality of resource capability and limitations defined in the inventory process. A key element of the process is to project the response of target and associated vegetation and livestock production to the treatments for the entire planning period. For planning periods that extend to the end of improvement in production attributed to the initial treatment, it often becomes obvious that a single practice is not economically viable. This realization leads to consideration of low-cost, follow-up or maintenance treatments that stretch the benefits of the initial high-cost treatment to the end of the planning horizon. Holding the benefits near the maximum level of improvement for extended time periods often makes possible a positive internal rate of return on the investment not possible from a single practice.

Therefore, IBMS include entire treatment sets that are evaluated through projections of expected response of vegetation, livestock, wildlife and other affected enterprises. These treatment sets are designed to facilitate synergism where possible. The strength of one practice or practices is used to offset inherent weaknesses in another. For example, the use of herbicides may remove valuable forbs from the range; however, these may be reinstated with prescribed fire. The projections of total response from treatment scenarios is plotted on response curves that quantify the annual level of increase in marketable production from the system. A partial-budget analysis using net present value of costs and benefits can then be used to predict an accumulated net present value of the investments and an internal rate of return.

An implementation protocol for IBMS requires that contingency plans be developed to accommodate changes in treatment scenarios caused by weather or other intangibles. Monitoring of the actual responses obtained from plan implementation will allow feedback into the system at the level of technology selection and economic analysis as well as initial objectives (Scifres et al. 1985).

3.5.3 Pest Control

3.5.3.1 Rodents

Many rangeland areas of the world are habitat for a wide variety of ground-dwelling herbivores that can impact the supply of forage to grazing livestock. Under most circumstances, these animals present little problem of environmental or economic consequence. It is apparent that rodents are usually considered less a threat as competitors to domestic animals on rangelands in high ecological condition. When range degradation occurs, the competition is dramatically escalated so that the rodents are more easily observed and often blamed as a threat rather than range overuse by grazing animals. However, when populations of rodents rise to extraordinary levels, control technologies may be justified. Large-scale use of pesticides (rodenticides) for rodent control has been practiced in North China and Inner Mongolia. The use of pesticides in such a manner would have environmental implications that must be considered. Moreover, the fundamental problem associated with a rodent-livestock competition for forage is often heavy overuse of the range by livestock. The fact that wide-scale rodent control programs may still be used makes this an area for consideration by projects dealing with livestock grazing and the environment.

3.5.3.2 Insects

Populations of insects that pose a threat to rangeland management are usually cyclical. During the periods of high densities, however, the presence of grasshoppers and other insects can be devastating to range forage supplies, particularly in areas of low precipitation where low forage production is further reduced by insects. Insects may move onto well-managed areas where range condition ratings are good. In reality, there is little that can be done about insect attacks on range forage production. The scale of the problem when it occurs, the cost of pesticide applications compared to the low production potential from rangeland, and environmental concerns relegate insect control to a low order of priority. However, like rodent control, insect control merits consideration in projects dealing with livestock and the environment. For example, there may be that grazing management decisions that could impact the severity of insect infestations.

3.5.3.3 Predators

The world's grazers have evolved livestock systems that accommodate the biology of their environment and their cultural requisites. However, the environment changes over time, while the social infrastructure to which it was tied may not change as rapidly. Changes in the relative composition of vegetation components, grasses, forbs, and shrubs on rangeland cause change in the habitat, including the forage/browse resource, available for livestock and wildlife. Maintaining a livestock system that includes cattle only when a large portion of the range forage supply comes from shrubs is inefficient. The use of goats in such circumstances would improve the total harvest efficiency of range forage and contribute to a better balance of vegetation components by added grazing pressure on the shrubs. Combination stocking with cattle and goats in such ecosystems has been demonstrated to improve range condition.

Problems are associated with bringing goats or sheep into stocking programs where only cattle have been used historically. Fencing required for goats is different from that required for cattle, and it is more expensive. Cattle-watering facilities are often inadequate for goats, and, because goats and sheep must be sheared for hair or wool production, working facilities on cattle ranches are unsatisfactory. Additionally, goat and sheep management requires different expertise, and markets may not be in reasonable proximity to areas not traditionally known for goat or sheep production. In some areas, goats and sheep may compete with an economically viable wildlife enterprise. Another major problem associated with changing livestock to better match range forage production is the threat of predation on the new animal. Eagles, domestic and feral dogs, wolves (coyotes), bobcats, and feral hogs are significant predators that can make sheep and goat production uneconomical without predator control.

In many cases, the potential for dramatically increasing the efficiency of utilization of range vegetation by stocking with combinations of kinds of animals makes it important to look at predator control. Projects addressing livestock grazing and the environment should consider the value of combination stocking in range improvement programs and determine if the control of predation of desirable components of the livestock mix is a realistic goal.

3.5.4 Range Nutrition

3.5.4.1 Nutritional Quality of Range Vegetation

The quality of range vegetation is correlated with season and plant phenology. There are usually parts of each year when the nutritional value of vegetation is high and low. Typically, plants are of highest quality during their growing season. Within the growing season there may be significant differences in nutritional quality between early-and late-growing season. Mature vegetation has a higher proportion of cell walls to cell contents and is less nutritious than young vegetation. During the early growth stages range grasses are highly digestible (50-70 percent), but decline rapidly as the season advances. Once into the dormant season, grasses lose quality as soluble cell contents are leached from the plants by precipitation. On ranges that have both warm-season and cool-season plants, grasses, forbs, and woody plants and cacti, there is much less variation in nutritional quality during the year. However, on most ranges there is still a period of high and low nutritional quality of the forage resource.

Matching of livestock nutritional requirements with the optimum season for nutritional quality from the range is an important element of livestock production systems. For example, overgrazing practices may be in part caused by low reproduction rates of breeding animals. In some rangeland systems, cows calve only on the average of every other year, or a 50 percent conception rate. In these systems, it takes 30 to 40 percent more mature breeding females to produce the same number of marketable offspring than in systems that provide greater than 85 percent conception rates. These “extra” animals greatly increase the grazing pressure on the forage resources. Moreover, in these low-yielding systems the mortality of the offspring is high, and the selling weights are usually low, compounding the problem of low reproductive performance. Furthermore, the facilities, labor, and variable costs associated with the higher number of animals all infringe on the opportunity for efficient production. Projects that involve livestock grazing and the environment should include studies of range animal nutrition.

There is a general relationship between the types of range plants and their forage value. Legumes normally have among the highest protein contents. Browse plants (many are legumes) tend to store food in the stems rather than roots; therefore, the grazable portion does not decrease in protein, vitamin A, and CHO content during drought or in the winter as much as grasses. Forbs generally do not cure well and are inferior as forage to both shrubs and grass during the nongrowing season. However, during their season of growth, forbs are usually the most nutritious component of range vegetation. Grasses cure well, particularly in semiarid and arid climates, and stand as an excellent source of energy during their dormant season. Shrubs more nearly maintain their peak value throughout the growing season.

3.5.4.2 Livestock Nutritional Requirements

Nutrient requirements of animals include protein to build and repair tissue, fats, and carbohydrates for production of energy; minerals for bone building, cellular formation, regulating pH in body fluids, and enzyme regulation; and vitamins which play a multiple role. If deficient in a mineral, animals cannot make efficient use of protein and energy in the diet. If the mineral, water, and vitamin requirements of the animal are met, however, needs can usually focus on protein and energy.

In developed countries, supplementation of minerals is common and cost efficient. In the western U.S., phosphorus is the most likely mineral to be deficient. It may be supplemented rather easily by phosphoric acid, bonemeal, and di-calcium phosphate. Phosphoric acid can be added efficiently to liquid feed. Phosphorus is used in enzyme and energy functions (metabolism). It is important in reproduction and weight gains.

Such trace mineral as Cu, Zn, and Mg may be supplemented with mineral blocks. For a small investment, livestock producers can be sure about these minerals which are normally marginally adequate in range forage. Potassium is a mineral that is readily lost from range forage plants by the process of leaching where it is transferred down to the roots and diffused by maturing plants. Therefore, mature, particularly dormant, forage may be deficient in potassium (Hinnant and Kothmann 1982). Potassium is stored for only about ten days in the body, so it must be replenished. When sources fall below levels required, excessive weight loss in cows, lighter weaning weights of calves, and higher calf mortality have been documented. Hay that captures adequate levels of potassium and molasses-based liquid feeds are good sources of potassium.

Among the vitamins, only vitamins A and D appear to be of significance in range animal nutrition. Since vitamin D is obtained from sunlight, it is unlikely to be deficient under range conditions. Vitamin A is important to animals for growth in the young, maintenance of healthy membranes, preventing night blindness, and in maintaining vigor and reproduction in adults. It is formed from carotene, found in abundance in fresh, green feed, and is likely to be deficient where animals are grazed on dry forage. Dosing breeding animals with vitamin A to enhance performance is common practice. Since the mineral and vitamin requirements of range animals can usually be met efficiently with low-cost mineral and vitamin supplements, the only real concern in most rangeland grazing regimes is for protein and energy.

Protein is needed for growth of the fetus and young animals and for the production of milk, horns, hair, and other fibers. Insufficient protein in livestock diets usually results from mature and weathered forage, low-grade hays, and insufficient forage availability. Dry, pregnant, mature cows have a total protein requirement of about 6.0 percent (concentration in ration dry matter). The same cow nursing her calf in the first 3 to 4 months postpartum has a total protein requirement of about 9.2 percent. Grazinglands that are composed of primarily warm-season grasses, or monocultures, such as tame pastures of either cool- or warm-season species, fail to meet protein needs for production for significant periods of the year. The higher protein content of forbs and shrubs on native range may become highly significant in meeting animal protein requirements through the grazing cycle. Where a natural source of protein is insufficient to meet needs, supplemental feeding must be employed. In the U.S., 41 percent protein cottonseed cake and 20 percent protein range cubes are standard sources of protein along with liquid feeds. Silage (sorghum or corn) can meet dry cow protein requirements but would be marginal for lactating cows without additives.

Energy is commonly referred to as the total digestible nutrients in a feed, or TDN. TDN requirements of the cow or other kinds of breeding females change drastically throughout the year. Whereas range grasses often are low in protein values during portions of the year, they are usually excellent energy suppliers, due primarily to the high cellulose content. Well-cured range grasses in much of the southwestern U.S. will average 50 to 60 percent TDN in dry matter. Energy problems on rangeland often are reduced to the amount of dry matter available for grazing animals. If the dry matter is not on the range, energy requirements will not be met.

The most critical energy concern to livestock producers is breed-back, or having breeding females conceive after calving. Cows must have above the yearly energy requirement to maintain, supply activities, produce milk for the calf, and cycle to conceive. If energy falls below the required level, cows will not conceive, and the next year's calf crop may be drastically reduced. A major problem in rangeland production systems is being able to predict the nutritional status of animals in time to mediate deficiencies and offset production losses. Each year is usually different in terms of amount and timing of precipitation, first and last frost date, and other factors that influence forage quality. While general supplement recommendations can be based on historical observations of livestock performance, there is too much at stake to guess.

3.5.4.3 Nutritional Mediation/Supplementation

There is clearly a need to determine the nutritional status of range livestock in order to optimize production. Some producers feel comfortable with a routine supplementation regime that works for them during most years. They begin to feed at about the same time every year and at about the same rate, and often with little reference to the nutritional regime needed to change production goals. Such supplementation programs are often very inefficient, feeding more or less than the optimum amount to meet objectives.

Accurately determining the protein and energy levels of range vegetation is no simple task. One method used is to hand pluck samples of the vegetation that is observed being consumed by livestock and have it analyzed. The turn-around time on such analyses is usually one to two weeks depending on the laboratory used (private or public) and the method of reporting (mail, express mail, fax, e-mail, or phone). The time delay in getting information from the analysis is a problem but not the greatest problem. It is improbable, if not impossible, that hand-gathered samples of vegetation will duplicate the actual diet of the animal. Within a grazing day, animals on rangeland graze different areas, different kinds of plants, different plants within kinds, and different plant parts. The heterogeneity of the vegetation available to grazing animals on rangeland and the preference-based selection process that they use makes it extremely difficult to duplicate. Therefore, hand-gathered samples can be expected to give only a general idea of the actual diet of the animals. In most cases, the animals will select a diet that is higher in quality than a hand-gathered sample, indicating the selection of specific plant parts of higher quality than others. The end result is that the value of the analysis is often questionable.

State Extension services and other agencies providing assistance to range livestock producers have developed profiles of forage quality that can be useful in determining generalized supplementation programs. However, these profiles also lack specificity to precisely identify what a particular herd of animals has selected and consumed. Although animals can be esophageally fistulated so that the actual diet that was selected by the animal is captured, this procedure is not suitable for free-ranging livestock, where animals must be caught to remove samples. The time required for chemical analyses is also a factor.

One method, which has great potential for accurately determining the nutritional status (protein and digestible energy) for range animals, employs near-infrared spectrometry (NIRS) and can accurately predict protein and digestible energy from samples of fecal material (Stuth et al. 1989). Fresh fecal samples taken from range animals are processed in the laboratory, and reflectance (wave lengths) is used to determine the sample nutrient content. This method gives an analysis of the actual diet selected by the animals sampled. It is also fast. Once a sample is received, the results can usually be communicated within 48 to 72 hours.

Samples are collected in the field as composites to represent herds of animals on the same range, feeding regime, etc. The samples are placed in plastic bags and then in a small styrofoam container with an ice pack. Samples have been kept in the styrofoam box for up to a week with no detrimental effect on the sample results. Photographs of the animals sampled and a worksheet to provide information on body condition score, etc., helps nutritionists make recommendations with the use of a computer software program called Nutritional Balance Analyzer, NUTBAL. NUTBAL uses the protein and energy analyses from the fecal samples and compares them to the levels needed to meet production goals. If there is a deficiency in the nutritional status of the diet, the program will provide a supplement recommendation to mediate the deficiency.

The use of NIRS technology should be evaluated in projects dealing with livestock production systems. Providing efficient nutrition to range livestock not only enhances production and ensures economical supplementation but also facilitates the use of fewer total animals to yield similar or greater production from the same land area.

3.5.5 Management/Marketing Strategies

Modifications in livestock production systems that may have a positive impact on rangeland vegetation and, subsequently, on soil protection, water quality, species biodiversity, and other parameters must be marketable. That is, there must be a demand for the product of the new system that offsets or exceeds the costs of implementation. For example, the addition of goats as agents to suppress woody plants may be practical considering their value only for brush control. However, it is more likely that the production from these animals must be counted as part of the benefits to offset costs. While there is evidence that interest in goats as a meat product in the U.S. is growing, there are large areas where demand for these animals would be marginal or nonexistent. It is possible that a demand could be created after the introduction of goats into an area, but prudent business procedures would require a preinvestment market analysis, an even more apparent need if the goats were angoras, producing hair for the market. In this case, an entire infrastructure of the mohair industry would need to be accessible, including labor for shearing, mohair markets, storage, etc.

In Inner Mongolia it is common practice for livestock producers to keep nonbreeding animals (castrates) is their herds for four to five years before marketing. In effect, the older animals kept in the herd are competing with the breeding animals, particularly the females that are the source of new production. If these nonbreeding animals were moved out of the herd, the forage resources they required could support additional breeding females, or contribute to greater individual production for each breeding animal (forage availability and nutritional-based increases in conception rates, weaning weights, etc.) However, no market incentive currently exists for Inner Mongolian herdsmen to sell weaned calves. Neither is there an infrastructure that can transport the young animals to sources of forage or drylot feed where they can be efficiently grown or fattened for slaughter, and there are no large-scale, efficient feedlot and slaughtering facilities. Moreover, there is currently no well-established demand for fed beef in any but the largest population centers in China. Therefore, regardless of how helpful changes in production systems may seem, unless all the pieces are in place to make the system work, change is not a valid consideration.

Projects or programs that evaluate livestock production systems and their impact on the environment must consider the constraints to change that exist. Without such analysis, the potential for implementing changes that will ameliorate environmentally untenable systems is extremely low.

3.7 Other Policies/Regulations Needed

3.7.1 Livestock-Wildlife Interactions

3.7.1.1 Recognition of Loss of Habitat

A long history of postsettlement overutilization in the U.S left degraded rangelands that we are now attempting to improve, with some success, through modified grazing systems (Vavra 1994). However, we cannot put the blame on grazing per se. Livestock grazing while a major environmental factor affecting grasslands, is a composite factor interacting in complex ways with other environmental factors. In the LGT of the north-central United States, intensive forestry that altered the frequency of natural fires and removed critical habitats has been practiced. Large herbivores, if given the opportunity to select complete habitats seldom negatively influence the ecosystem. When those habitats were altered, removed, or migrations were restricted, then degradation of the habitat can be expected. The United States today has no complete habitats, and we are forced to manage all our lands intensively. Failure to recognize this paradigm can result in severe ecological problems even in national parks (Chase 1986). If land managers (public and private) are to successfully manage livestock and wildlife, we must recognize where we are ecologically and accept that the true natural ecosystem no longer exists. Only through intensive management of livestock and wildlife can we have viable, diverse ecosystems that are sustainable.

3.7.1.2 Environmental Monitoring

Decreases in water quality can detrimentally affect many wildlife species as well as stream structure and habitat. Monitoring to determine livestock impacts needs to be focused on factors that limit beneficial uses of the watershed, identify site-specific impacts caused by grazing, and target the parameters that link the effect of grazing with the resulting impact on the beneficial use.

3.7.1.3 Appropriate Level of Resolution

The landscape level is where conflicts between cattle and wildlife should be addressed (Cooperrider 1994). The landscape boundaries may be defined by a watershed, a planning unit, a county, a bioregion, or some other combination of topographic, biological, and political attributes that works. At the landscape level, programs can be developed that both conserve the biological diversity and also maintain the health and welfare of the human population within such landscapes, including those inhabitants deriving their livelihood from raising cattle. This concept is similar to, if not synonymous with, the original concept (and the reality) of a biosphere reserve (Hough 1988); it is also compatible with the growing bioregional movement which emphasizes development of semi-independent regional economies (Sale 1985).

Many writers have pointed out that sustainable ecosystems or landscapes are required for sustainable economies and societies (Jacobs 1986, Maser 1988). The ecosystem or landscape is the source of virtually all the amenities and commodities that sustain our way of life, and biological diversity may be thought of as the basic components and processes of ecosystems. Thus, sustaining healthy ecosystems (i.e., conserving biodiversity) should be a fundamental guiding principle in developing programs at the landscape level.

Based on the above premises, the criteria of sustainability should provide the guidance needed to resolve livestock-wildlife conflicts and to determine if programs are successful. If cattle can be grazed in such a way as to preserve the biological diversity and ecological integrity of the landscape, then reasons for opposing such grazing become limited. There are many areas that have been grazed by cattle for many years with no apparent or documented loss of biological diversity. In other areas, cattle grazing, as currently practiced, is incompatible with maintaining biological diversity. Utilizing a criteria such as sustainability at the landscape level may help move society away from the extreme polarization that now exists in many places and towards constructive resolution of these conflicts.

Developing solutions at the landscape level will require an unprecedented level of cooperation and communication between different public and private interests and disciplines. However, there are examples where such approaches have worked.

3.7.1.4 Equilibrium Versus Ecologic Carrying Capacity

Allocation of grazingland between large wild and domestic herbivores should not be based on social or economic perceptions of special interest groups (Sheehy 1994). Rather, it should be based on the optimum stocking rate of herbivores that enables an equilibrium carrying capacity to be sustained. Although the influence of economic criteria and social needs on management of grazinglands is undeniable, management of grazingland use by herbivores should be based on ecological principles. Compromise of ecological principles beyond strict limits to satisfy economic criteria or social needs inevitably leads to degradation of the grazingland ecosystem.

Determination of the correct stocking rate for herbivores based on ecological principles may require that wild and/or domestic herbivore populations be adjusted to the desired equilibrium carrying capacity of grazingland. Management for equilibrium carrying capacity allows upward or downward adjustment of the stocking rate of one or more herbivores to obtain the desired equilibrium. Equilibrium carrying capacity has the highest potential for satisfying social and economic needs of all special interest groups.

Managing herbivores to maintain vegetation at equilibrium carrying capacity may be difficult because of inadequate knowledge concerning cause and effect relationships between herbivores and between herbivores and grazingland vegetation. On grazingland receiving multiple use by different kinds of large herbivores, knowledge of the response of grazingland vegetation to the multiple use will be needed in determining correct stocking rate. Although information on herbivore or vegetation response often exists, it may be inaccessible or unavailable to the manager within the time period allotted for decisions on stocking rate adjustments. This knowledge is crucial in establishing herbivore stocking rates that will maintain grazingland vegetation at the desired equilibrium carrying capacity.

Allocation of grazingland and forage to large wild or domestic herbivores is often a volatile issue and the basis for conflict between livestock producers, wildlife and land management agencies, sports groups, environmental conservationists, and, more recently, animal rights groups. The concern over use of the grazingland resource being shown by special interest groups and much of the public has forced the livestock industry into a defensive posture concerning priorities for allocation of grazingland, especially grazingland in the public domain.

Attitudes are widely divergent, both within and between special interest groups. The livestock producer may be concerned with possible competitive interaction between wild and domestic herbivores for a scarce forage resource or the infringement by wild herbivores on prior rights to use grazingland for livestock production. Conversely, livestock producers often acknowledge that wild herbivores may be an integral and enjoyable part of the ranching experience and present an economic opportunity to supplement ranch income. Sports hunter attitudes vary from the desire to exclude domestic livestock from grazingland to allow for increased availability of habitat for large wild herbivores to having an economic relationship with the livestock producer to ensure hunting privileges on privately owned land. Environmental conservation groups and segments of the general public often express the view that domestic herbivores are ecological intruders that cause damage to the grazingland environment far in excess of any economic value to society as a whole. Publicly funded wildlife and grazingland management agencies often appear to be in a no-win situation because of the necessity to respond to all special issue groups while at the same time managing the resource on a sustainable, ecological basis. Animal rights groups are in the process of adding an entirely new dimension to the issue of grazingland allocation by questioning the ethics of hunting and the methods used in livestock production.

Conflict over allocation of grazingland between large-herbivore users arises from different interest groups having different perspectives as to what constitutes acceptable use of grazingland. The beef cattle producer is generally motivated by economic priorities of the livestock production system (Conner 1991). Current management of wild herbivore populations, while based on ecological principles, is influenced by economic principles and social attitudes. Grazingland, which forms the resource base for much of the livestock industry as well as for wild herbivores, requires management based on ecological principles (Heitschmidt and Taylor 1991).

Integrating the ecological, economical, and social priorities to arrive at management capable of sustaining the grazingland resource is often not accomplished. On public grazinglands, ecological deterioration of grazingland vegetation and soils associated with past or present overstocking generally results in reduction of herbivore numbers or restrictive regulations on grazingland use. Attempts by management agencies to restore or maintain ecological conditon of grazingland vegetation can result in removal of all domestic herbivcores from areas of grazingland considered critical for other uses.

The influence of ecologic, economic, and social pressures on management of large-herbivore use of grazinglands can be explained through the concept of equilibrium and ecologic carrying capacity (Conner 1991). Populations of large, wild herbivores in a natural grazingland ecosystem maintain an equilibrium with vegetation by adjustment of population numbers to the grazingland's ecological carrying capacity. As used here, ecological carrying capacity represents grazingland carrying capacity in the cycle of herbivore population growth and decline. In this cycle, the herbivore population at high numbers exceeds the carrying capacity of grazingland. The reduced carrying capacity (caused by changes in species composition and yields) initiates a decline in herbivore numbers in response to declining supplies of food. As herbivore numbers decline, the stress on grazingland vegetation is reduced, and succession to higher ecological condition as recovery takes place increases carrying cpacity. Eventually, populations of herbivores recover and the cycle is repeated.

Management through sustained harvesting, as currently practiced by most wildlife management agencies, is management based on equilibrium carrying capacity. Herbivores are not allowed to reach maximum potential numbers, and forage remains in excess of forage demand. An equilibrium is attained that is sustainable as long as herbivore numbers are maintained at levels below or equal to grazingland carrying capacity. Either of the above carrying capacity scenarios operating without external influences has the potential for maintaining long-term sustainability of both the herbivore population and the grazingland resource, although ecological carrying capacity would allow fluctuations to occur in both the herbivore and plant population.

This logic is equally applicable to management of wild or domestic herbivore populations, if the wild or domestic herbivore is the sole user of the grazingland resource. The livestock producer ideally operates under equilibrium carrying capacity if stocking rate of domestic herbivores is maintained at levels allowing for long-term ecological stability of grazingland vegetation. A goal of most wildlife management agencies and livestock producers is to maintain their respective population of large herbivores at a certain stocking rate based on equilibrium carrying capacity of the grazingland resource. The conflict arises if either perceives the other's herbivores as reducing the opportunity to maintain their respective herbivore numbers at sustainable levels relative to the equilibrium carrying capacity. If competition for scarce resources does become reality, then both production systems are actually operating at ecological carrying capacity in which populations of herbivores would fluctuate in response to availability of forage plants. In this scenario, the response of both wild and domestic herbivore populations to operating at ecological carrying capacity would be die-offs unless costly supplemental feeding operations are initiated or herbivore populations are reduced to attain a new equilibrium with carrying capacity.

In the event competition between large wild and domestic herbivores for scarce grazingland resources does change grazingland carrying capacity from an equilibrium to an ecologic carrying capacity, most special-interest groups should be in favor of adjusting herbivore numbers to reestablish equilibrium carrying capacity. Sports hunters would favor it because of the opportunity to hunt. Environmental conservation groups and grazingland management agencies would favor it because ecological deterioration of grazingland would be a salient feature, at least in the near term, of having the system at ecological carrying capacity. Livestock producers would favor equilibrium carrying capacity because of economic losses to the production system associated with declining grazingland productivity under ecological carrying capacity. Wildlife management agencies would favor equilibrium carrying capacity because allowing die-offs of large wild herbivore associated with ecological carrying capacity would not be acceptable either to the management agency or the public.

The special-interest group possibly in favor of ecological carrying capacity over equilibrium carrying capacity might be animal-rights groups. Animal-rights groups are challenging the strategy of equilibrium carrying capacity for both wild and domestic herbivores by attempting to regulate the consumptive elements of production, i.e., hunting or livestock management methods.

3.8 Research

See Section III-3.7.