Biodiversity Research: The Cultural Context
Human beings have occupied this planet very thoroughly for thousands of years, and few "natural" habitats remain. The landmasses of the Earth are largely covered by mosaics of habitats that have been altered to a greater or lesser degree by a rich diversity of human action. Some of these areas are occupied by people who have developed approaches to managing the resources of their local ecosystems in a sustainable fashion, while others are occupied by people whose activities have recently altered those systems to such a degree as to call their sustainability into question.
For most of these thousands of years, anthropogenic environmental impacts were largely confined to local areas, and took place at a rate that allowed societies and their resource base to adjust to one another and maintain themselves in a general state of equilibrium. Relatively sparse human populations; subsistence technologies; local control over resources; land ownership by clans, ancestors, or lineages rather than individuals; and other social mechanisms protected much of the natural world from the massive degradation that is now leading to widespread loss of biological diversity.
This, however, was never an ideal world; the "Garden of Eden" vision contains its weeds. The equilibrium was not a static state. Where human hunters moved into new habitats filled with naive game animals, major extinctions have occurred; the Americas, Australia, Madagascar, and New Zealand provide well-known examples (Martin, 1984). Humans are also implicated in the extinction of some 90 percent of the endemic mammalian genera of the Mediterranean after the development of agriculture (Sondaar, 1977). Ancient human settlements occasionally visited deforestation, desertification, and salinization upon their lands, and eviction upon themselves, in the course of their development.
Although hunting and agricultural societies have long had the power to transform their environments and drive species to extinction, it
remains a valid observation that the natural world at the dawn of the industrial age was characterized by highly diverse ecosystems and supported highly diverse human cultures. In the past few generations, however, as fundamental ecological changes have taken place, the world's heritage of natural and cultural diversity has been diminished.
DIVERSITY AND DEVELOPMENT
These shifts have both caused, and been caused by, social changes. The world's collection of highly diverse cultural adaptations to local environmental conditions has begun to be replaced in many locations by a world culture dominated by very high levels of material consumption. Economic growth based on the conversion of fossil fuels to energy has greatly expanded international trade. Improved public health measures have spurred a rapid expansion of human numbers, requiring new approaches to resource management. These approaches have overwhelmed the conservation measures (formal or informal) of local communities, bringing overexploitation and poverty to many rural communities, and great wealth to cities and certain individuals, as urban elites in both industrial and developing countries control policies in such a way that primary productivity is very poorly rewarded.
Technological innovations have tended to promote exploitation of biological resources and to weaken traditional management systems, especially when a dominant group moves into a region occupied by technologically less advanced groups. The dominant society has the option of moving on to fresh resources when an area is exhausted, and it derives no particular advantage from adopting traditions of sustainable use. Its members are able to earn virtually all the immediate cash benefits of a forest, for example, but pay almost none of the long-term environmental costs. In addition, they capture a very small fraction of the potential cash benefits from the forest through short-term exploitation, rather than greater income from judicious long-term management in cooperation with local peoples.
At the same time, the subordinated groups lose any advantage from traditions of conservative use that might have been favored in times when they could exclude other groups from their territory. These traditions evolved when costs and benefits were internalized in the decisions made by communities, but as local peoples have had to assume the higher environmental costs of resource degradation, often their only rational response has been to join the exploiters in seeking greater benefits as well. This is the real tragedy of the commons: traditional management systems that were effective for thousands of years become obsolete in a few decades, replaced by systems of
relentless exploitation of rural people and rural countries, those who depend on primary productivity. Exploitation brings short-term profits for a few and long-term costs for many throughout the world.
Diversity, both biological and cultural, is a casualty of this process and of the operant development paradigm behind it. In the push, for example, to modify local farming systems to accommodate modern Western technologies and to put in place the institutions required to manage these technologies, little heed has been given to the complexity of systems such as tropical rain forests or their indigenous peoples. As more consumptive exploitation of biological resources occurs, cultural diversity is often reduced, for two main reasons. First, a significant component of cultural diversity that enables people to earn a living from the local biological environment is no longer functional; second, subordinated groups must often imitate the culture of the dominant group, thereby losing a substantial portion of their cultural identity and, hence, their diversity.
The World Commission on Environment and Development (1987) described the process:
Growing interaction with the larger world is increasing the vulnerability of isolated groups, since they are often left out of the processes of economic development. Social discrimination, cultural barriers, and the exclusion of indigenous people from national political processes make them vulnerable and subject to exploitation. Many groups become dispossessed and marginalized, and their traditional practices disappear. They become the victims of what could with justice be described as cultural extinction.... It is a terrible irony, that as formal development reaches more deeply into rain forests, deserts, and other isolated environments, it tends to destroy the only cultures that have proved able to thrive in these environments.
As noted in the previous chapter, the desirability and sustainability of the standard development paradigm are being challenged by growing numbers of people in the developed and developing nations, and within the international development community. This comes as a variety of profound impacts of environmental exploitation—including not only the loss of biodiversity that is the focus of this report, but also associated concerns about human population growth, depletion of the Earth's ozone shield, and possible changes in climate resulting from anthropogenic emissions of greenhouse gases—suggest the inevitability of changes in the way humans relate to the global environment. In this context, the need for more sustainable development strategies and technologies has become apparent, and awareness is growing that
The Demographic Context
Since 1950, the world's human population has more than doubled, from 2.5 billion to its present level of 5.4 billion (PRB, 1989). Of these people, 77 percent live in developing countries and control about 15 percent of global wealth. One billion people will be added to the developing countries in the 1990s, at the rate of more than 90 million people (the population of Mexico) per year. At the same time, topsoil is being lost from the world's agricultural lands at the rate of about 25 billion tons per year, and about 20 percent of the total has been lost since 1950. This trend is essentially irreversible: in the tropics, it takes about 100 years to build an inch of topsoil, and little additional prime land is available for cultivation. We are already managing global ecosystems; our challenge now is to manage them well and not remain passive while allowing them to deteriorate.
traditional community-based resource management systems have much to offer as a new development paradigm emerges.
LOCAL KNOWLEDGE AND BIODIVERSITY
Only by determining why people do what they do can we understand the relationships between people and their biological resources. Which species are most valued for food, medicines, construction, or ceremonial uses, and why are they treated in certain ways? Why do people locate their houses in certain ways in relation to the landscape? Why do subsistence farmers conserve low-yielding local cultivars? Underlying all of these questions are behavioral factors that must be understood, because they determine how people will respond to external pressures that influence their use of resources.
The social sciences can mediate between indigenous resource use patterns and other institutions by examining indigenous knowledge to understand the problems of biodiversity loss and the methods for biodiversity conservation. The social sciences help identify not only the components of the local knowledge system, but also the timing, behavioral processes, and structural characteristics that result in the conservation or reduction of biological diversity.
Recently, some individuals in the development community have argued that local knowledge can point toward new types of sustainable agriculture, natural resource management, and conservation (Peters et al., 1989). They propose that greater benefits can be gained by managing a rain forest for sustained extraction than by converting it through more intensive methods. Furthermore, they suggest that the local knowledge system may yield new ideas about the conservation and management of valuable products and identify valuable new biotic resources for utilization. This point of view constitutes a welcome departure from traditional thinking about local knowledge, but may actually encourage the depletion of biological diversity if it seeks merely to identify those efficiently marketed species and goods known to local peoples and fails to comprehend the complete contextual system in which local cultures operate.
As development agencies have come to understand the need to conserve biodiversity and the complexity of the ecosystems and cultures that this task entails, they have recognized the vital role that local peoples—defined variously as indigenous, tribal, traditional, or subsistence—must play in the conservation process if it is to succeed. Yet this recognition has rarely been extended to include the belief that local people can contribute more to the conservation process than simply their acquiescence. Why?
Local people, those who have developed apart from the dominating society that is penetrating their area, play an important role in maintaining biodiversity. Little is known about the resources many of them use and why they use them. Less is known about why they shape ecosystems as they do or about their concept of landscape and the institutions used to enforce such concepts. Local people are expected to be what the dominant society anticipates; it is assumed that local knowledge does not exist or will be beneficially replaced from without. In reality, however, local knowledge not only exists but may make important contributions to the conservation of biodiversity.
Nature of Local Knowledge
Local people, depending on a number of historical, social, and ecological factors, amass an extraordinary store of knowledge about the local natural resource base. Some groups not only construct taxonomies of plants and animals based on useful characteristics, but also compile information on species abundance and distribution (Berlin et al., 1974). Many of these taxonomies are extensive. The Maya of southern Mexico and Guatemala, for example, include not only plants and animals, but soils and ecological communities and successions in their classification schemes (Gómez-Pompa, 1987). The Huastec Maya include 950 species of plants in their classifications; this represents 89
Traditional Management Patterns
Many local peoples have developed complex management patterns for biological resources. The Kayapo of Brazil manage more than 600 plant species in a complex agroforestry system that is intensive, diverse, and sustainable. Peruvian pastoralists rotate animal grazing in high-elevation pastures to maintain mixed-species pastures and thereby ensure food for their flocks even during periods of climatic stress. Australian aborigines had an elaborate fire management regime that controlled the frequency of severe fire and simultaneously maintained high levels of productivity and biodiversity in the outback. Farmers in centers of crop diversity have nurtured a considerable degree of variety in their crop germ plasm. Andean farmers, for instance, keep thousands of potato varieties, adapted to a wide range of edaphic, topographic, climatic, and altitudinal conditions (Brush et al., 1981).
percent of the local flora, 70 percent of which were used in one way or another (Alcorn and Hernandez, 1983). Since local taxonomies are based on use, they are a source of basic botanical information and they also suggest species that might be developed into market commodities.
These examples show that local people identify and classify useful plant and animal species, describe ecological communities in an environmental context, and test and evaluate species for their useful potential. Using this knowledge, they design, test, and develop resource use patterns, establish microenterprises and markets, and develop mechanisms for transferring knowledge from one generation to the next.
Local resource use patterns, then, are not static, outmoded, or unsophisticated, but neither are they suitable to institutionalization in the manner generally promoted by development agencies. There is no single traditional knowledge system that can be used to preserve biological diversity in all rain forests or on all semiarid rangelands, but no modern technological system can perform this function either. The management systems that local people use are based on, and take advantage of, the biological diversity of particular locales. Although they are believed to be suitable only at relatively low population densities, they are critical sources of insight into agroecological principles that can be incorporated into more complex intensive
systems. In short, we need to understand the diverse ways in which rural people relate to their environments and the degree to which such relationships are sustainable.
In many parts of the world, large numbers of people farm small areas of land that fulfill their needs, without regularly using modern agricultural inputs such as chemical fertilizer, high-yielding crop seeds, or commercial pesticides, and they harvest and store their grain using techniques that have been employed for generations. In Africa, for example, the World Bank (1989) estimates that the average use of chemical fertilizer is less than 10 kilograms per hectare, compared with about 90 kilograms per hectare in China and India.
Most of these farmers employ some form of shifting (or swidden) agriculture. In this traditional system, the farmer clears land that has been left fallow for anywhere from 6 to 25 years (Christonty, 1986), uses or sells the valuable woody material for construction or charcoal, and burns the rest in situ to provide nutrients for his next crop. The system depends on natural or managed revegetation to restore fertility to the ground when it can no longer support crop production. How long and how much the land will produce are functions of the inherent fertility of the soil, drainage and leaching rates, human management of vegetation, the degree to which animals are used in plowing or otherwise contribute their manure, and the rate at which the area is encroached by weeds and other pests.
The interplay of these factors determines when the farmer will move to another plot. In some parts of Ethiopia with volcanic soils, farmers have been able to produce between one-half and one ton of grain per hectare every season on the same land for as far back as memories stretch, perhaps hundreds of years, so that shifting is not imperative. In Ghana, by contrast, on well-drained savannah soils, only two or three crops can be produced before the soil is exhausted; weeds make further use impractical until it has fallowed, preferably for 15 years (now often reduced to 5 years because of lack of alternative available land, and therefore with much less recovery and buildup of fertility).
In its traditional form, shifting agriculture depends on the biological diversity of surrounding areas to sustain the natural cycle of clearing and revegetation. In recent decades, however, fallow times have been shortened as a result of population increase (due to both high birth rates and immigration by nonnative farmers), the resultant pressure on land, ineffective pricing policies, and faltering industrial development.
This has several consequences. Restoration of the soil through the action of deep-rooted trees and shrubs, particularly leguminous species that fix atmospheric nitrogen, may be interrupted. The amount, diversity, and quality of biomass produced are lower; consequently, the amounts of biomass or nutrients available for the next cycle are reduced. The process of succession, in which different plants take advantage of different opportunities presented during the successive stages of regrowth, may not continue sufficiently for some species to mature; hence species and biodiversity may be progressively lost. The reduction in diversity often means special losses to the local people, who may depend on regrowing areas for supplements to their diets (seasonal fruits, nuts, small animals) and for a wealth of useful natural products (herbs, dyes, tannins, creepers for cordage, leaves for thatch, and traditional remedies for a wide variety of ailments).
The modernization of agriculture, including the intensification of fallow management and use, has generally been pursued through development schemes that attempt to substitute technological resources for natural resources. This may succeed in helping the farmer farm the same land continuously by using fertilizer, pesticides, and other purchased inputs, but it is seldom able to compensate for or to restore the surrounding diversity of biological material. It brings with it the susceptibility of monocultures to any number of problems, including decreased resistance to pests and drought, and increased dependence on the affordability and availability of hybrid seed, fertilizer, pesticides, and other inputs. Meanwhile, knowledge about the broad range of natural products from the ''bush'' is dwindling as the amount of bush itself dwindles and as children no longer absorb the lessons of their elders.
Intensive Agricultural Systems
Two types of intensive systems dominate production agriculture in the lowland humid tropics: swamp or paddy rice production systems and perennial tree crop plantations. Swamp rice cultivation is a product of the evolved complex system of land and water management that sustains huge populations in East, South, and Southeast Asia, and has been copied successfully in parts of Central and South America. It involves backbreaking work, and the social organization of communal labor that land preparation, transplanting, irrigation, and harvesting entail has limited the successful development of analogues elsewhere. In Africa, local waterborne diseases—especially filariasis, river blindness, and schistosomiasis—make year-round cultivation with irrigation singularly difficult, although upland rice cultivation has been more successful.
Lun Dayeh of Northeastern Borneo
The Lun Dayeh of East Kalimantan in Indonesia practice both shifting and permanent field irrigated cultivation of rice and a number of subsidiary crops, and are noted throughout much of Borneo for their abundant annual rice harvest. The success of Lun Dayeh farming has been attributed by many not familiar with the group's homelands to extremely favorable natural conditions for agriculture, particularly fertile soils. A closer examination, however, shows that the Kerayan Subdistrict, where most of East Kalimantan's Lun Dayeh live and farm, is a highly varied region, blessed only in very limited areas with exceptionally good conditions for rice production. The success of Lun Dayeh agriculturists is more reasonably attributed to their detailed knowledge of the environments they exploit, sound judgments of where to site their fields, and good management practices.
Like shifting cultivators and other traditional agriculturists throughout the world, the Lun Dayeh of East Kalimantan's Kerayan Subdistrict weigh a number of environmental variables before selecting a site for a new agricultural field. Although the environmental variables most important to swiddeners—including the composition and height of the vegetation covering the area—are taken into account, Lun Dayeh permanent field cultivators tend to be more concerned with other environmental characteristics including slope, water quality and availability, drainage, and soil quality both on and below the surface. Moreover, they attempt to judge the long-term acceptability of the site. Therefore, continuing observation of an area, often for years before it is first used, is not unusual. Although the criteria for an acceptable site for an irrigated farm field are many, Lun Dayeh cultivators assume that some changes will be necessary to bring a field to the condition required. Therefore, a most important consideration is the amount of labor that will be needed to render a site acceptable for pond-field farming. Because population density in the Kerayan is low and almost ideal areas are still available, Kerayan Lun Dayeh farmers continue to reject any site that requires major improvements such as significant terracing work, filling in sites that tend to flood too deeply, or digging long irrigation canals. As most easily worked areas are claimed in the future, what is judged an acceptable site will certainly
change, and the construction of ever more labor-demanding engineering works will be considered necessary and reasonable.
Another facet of this process is found among the Ifugao of Luzon. According to the reports of Conklin (1980), in choosing a site, the Ifugao, consider the incline of an area the most important criterion. Because flat or gently sloping lands are no longer available in Ifugao, an acceptable slope is far more steep than any site that the Lun Dayeh would attempt to exploit. Also important are the availability of a water supply upslope from the chosen site and the location of materials necessary for building terraces in the vicinity of the selected area; these include wailing rock, rough fill, and topsoil. In the Ifugao case, cultivators expect not to find, but rather to create, most of the conditions necessary for pond-field farming; their fields, in contrast to those found in the Kerayan, can be considered largely artifacts, because the soil, including subsoil and the entire surface of each terrace, has been created with human labor.
The willingness and ability to alter environmental conditions, which in large measure distinguish Lun Dayeh pond-field farmers from their swiddening counterparts, are considerably more developed among wet rice farmers such as the Ifugao whose homelands offer fewer unexploited ideal sites for irrigated cultivation. A comparison of labor needed to create pond fields in different areas would be interesting but difficult because of the great variability of sites available in each location. However, initial pond-field creation costs, as well as subsequent labor for maintenance in regions such as Ifugao, surely far surpass those found in the Kerayan. With ever-increasing alteration of the original environment, the need for human labor in maintenance increases as well. The Lun Dayeh, therefore, in seeking out areas that naturally approach most closely the conditions desirable in an irrigated pond field are minimizing not only initial construction costs but also subsequent maintenance (Padoch, 1986).
Perennial plantations of tree crops have been extremely successful throughout the tropics, to the extent that overproduction and control by industrialized countries of the markets for rubber, coffee, cocoa, tea, copra, palm oil, and other commodities have led to steadily falling prices. Of special interest now are possibilities for diversifying forest
productivity, based on an understanding of traditional systems practiced in Southeast Asia and South and Central America. In diversified plantations, a mixture of useful species is maintained, providing the farmer with a broad range of products, including tropical hardwoods; fruits and other edible products; oils and resins; livestock and wild game; and rubber, cloves, cinnamon, or other cash crops. Recent studies of the Peruvian Amazon have shown that the value of products obtained from extractive reserves of forest can exceed the value of production of food crops or ranching on converted forest areas (Peters et al., 1989).
Pastoral nomadism is another type of cultural adaptation to drought or aridity and, in many cases, to the health and pest problems associated with settled agriculture. Arid lands support large populations of people and animals—an estimated 135 million, or about 20 percent of the world's population, and most of the 3 billion head of domesticated livestock (NRC, 1990). Moisture limits the productivity of the systems, which are necessarily much more extensive than the systems of tropical lowlands and forests.
There are two general systems of rangeland utilization: systems that use the land to produce goods that are removed or exported (ranches), and those that chiefly provide subsistence for people associated with livestock and wildlife populations (indigenous pastoral systems). Contrary to popular belief in industrial nations, pastoral systems are not necessarily less productive than ranching systems. African pastoral systems, for example, are often as productive as market-oriented ranching systems in comparable areas in terms of protein produced per unit of land utilized.
Most ranches are privately owned and characteristically use both the investment of capital and various management techniques on large areas of land to increase livestock production. Unlike pastoral systems, labor inputs are low. Hence, ranching often produces more protein per hour of labor than does pastoralism. On the other hand, ranching requires vastly greater inputs of energy, and the expenses incurred in connection with fencing, water development, brush control, revegetation, grazing management, and selective breeding are substantial.
Rangeland ecosystems, particularly those in arid and semiarid regions, are highly susceptible to degradation. In many regions, degradation is chiefly a result of changing herd composition and overstocking. Particularly noteworthy since the advent of the colonial period has been a shift in herd inventories favoring cattle, a form of livestock poorly adapted to dryland ecosystems, at the expense of well-adapted and less environmentally destructive forms, such as
Pastoral systems represent the principal form of rangeland utilization in Africa and Asia. They involve significant social adaptations to the movement of livestock or wildlife from one location to another in relation to the availability of forage and water, and the avoidance of diseases such as trypanosomiasis (sleeping sickness) which in Africa is endemic in wetter areas where the trees that are the habitat of the tsetse fly vector are found. The rangelands utilized are seldom privately owned, and mechanical or chemical inputs are seldom prominent. The systems are labor intensive. It has been estimated that livestock and wildlife support some 30 to 40 million pastoralists, and the animals and animal products associated with pastoral systems are critical to millions of other individuals in settled communities (World Resources Institute, 1987).
The importance of livestock in pastoral systems exceeds their value as sources of milk, meat, blood, and hides. Livestock often represent a means of accumulating capital and, in some societies, are associated with social status. They are assets that can reproduce and can be liquidated should cash be required. In addition to supporting livestock, rangelands serve as sources of other significant economic products: bushmeat, fruits, berries, nuts, leaves, flowers, tubers, and other food for human populations, as well as medicinal plants, building materials, thatch, fencing, gums, tannin, incense, and other products important to the economies of rural populations (Sale, 1981; Malhotra et al., 1983, National Research Council, 1983).
The importance of rangelands as sources of bushmeat and vegetable foods for human populations deserves special attention. These foods are derived from species that are well adapted to the environmental peculiarities of the regions in which they are found. Hence, such foods are often available in the event of crop failure or substantial loss of livestock. Even during periods with average rainfall, satisfactory crop yields, and herd stability, such foods constituted a significant part of local diets. Indeed, in many societies, the offtake of wildlife from rangelands exceeds that of livestock in importance. In 1959, for example, the sedentary and pastoral peoples of the Senegal River Valley in West Africa relied on fish and wildlife for more than 85 percent of the meat they consumed (Cremoux, 1963); native
plants were of equal or greater importance. Since that time, widespread environmental degradation has dramatically reduced the availability of natural products associated with local coping strategies and has correspondingly increased the vulnerability of rural populations (NRC, 1983). In most instances, the degradation is a result of breakdowns in the traditional resource management systems that for centuries have maintained an equilibrium between environmental systems and human activity (NRC, 1986b).
camels, because the former are more marketable in the context of the new economic order (Chassey, 1978). In the West African Sahel, for example, colonial policy resulted in an almost fivefold increase in the cattle population between 1940 and 1968.
Agricultural expansion has also contributed to the degradation of tropical and subtropical rangelands. In drylands, agricultural expansion results in increased pressure on rangelands because conversion of the more productive forage reserves to cropland forces pastoralists to overgraze the remaining land base (Thomas, 1980). Moreover, grain crops deplete soil nutrients at a rate 30 times greater than the rate of nutrient loss in a properly stocked range ecosystem. The cost of replacing the lost phosphorus, potassium, nitrogen, and other nutrients is generally prohibitive.
In many regions, high levels of sustained use pressure have eliminated the more palatable plant species. In dryland ecosystems, plant growth is relatively slow. When aerial biomass is consumed by foraging livestock, many plants respond by transferring nutrients from their roots to produce new leaves, which results in reduced rooting. Reduced rooting, in turn, decreases the ability of the plant to absorb moisture and nutrients even during rains. As the more palatable species are weakened with continuing high levels of use pressure less palatable species of undesirable shrubs, grasses, and forbs become dominant. As these species are overgrazed, the land surface is exposed to further, more severe, degradation. In the drylands of Africa and Asia, cattle have been particularly destructive. Unlike camels, goats, and most native herbivores, which are predominantly selective browsers, cattle are grazers; they therefore increase the pressure on perennial grasses and often eliminate them, causing ecological deflections toward ephemeral annual grasses and relatively unproductive trees or shrubs, such as Calotropis procera (Gaston and Dulieu, 1976).
The reduction or elimination of vegetative cover, in combination with trampling and compaction of the surface by livestock, reduces
Among the Lua (Lawa) of northern Thailand, about 120 crops are grown, including 75 food crops, 21 medicinal crops, 20 plants for ceremonial or decorative purposes, and 7 for weaving or dyes. The fallow swiddens continue to be productive for grazing or collecting, with well over 300 species utilized. The most important crop is upland rice, and it is not unusual for 20 varieties of seed rice to be kept in a village, each with different characteristics and planted according to the soil, fertility, and humidity of the fields.
The Hanunoo of the Philippines may plant 150 species of crops at one time or another in the same swidden. At the sides and against the swidden fences grow low climbing or sprawling legumes—asparagus beans, sieva beans, hyacinth beans, string beans, cowpeas. Toward the center of the swidden, ripening grain crops dominate, but many maturing root crops, shrub legumes, and tree crops are also found. Pole-climbing yam vines, heart-shaped taro leaves, ground-hugging sweet potato vines, and shrublike manioc stems are the only visible signs of the large store of starch staples building up underground, while the grain crops flourish a meter or so above the swidden floor before giving way to the more widely spaced and less rapidly maturing tree crops. A new swidden produces a steady stream of harvestable food in the form of seed grains, pulses, sturdy tubers, bananas, spices, and many others.
Among the Tsembaga Mareng of Papua New Guinea, each field contains some 10 to 15 major crops, plus dozens of minor crops, spread seemingly at random through the field. This intermingling discourages plant-specific insect pests and takes advantage of slight variations in garden habitats. It also protects the thin tropical soil and achieves a high degree of photosynthetic efficiency.
The ribereños of the Peruvian Amazon, nontribal descendants of the indigenous inhabitants, have adapted traditional swidden-fallow agroforestry patterns to the market economy. They largely retain the age-old cyclic system, following a diverse planting of annual and semi-perennial crops with a mixture of perennial tree crops and forest species. However, they have also altered the traditional system in several crucial ways. At each stage of the cycle, which may be 25 years or longer, the particular choice of crops and methods
is determined both by the opportunities the markets present and by the subsistence needs of villagers. Households in some ribereño villages gain yearly incomes of $5,000 or more from their agroforestry fields while still maintaining a high diversity of crops and the productive potential of their lands.
infiltration and permits the mobilization of soil particles subject to transport by overland flow. This results in depressed groundwater tables and increased soil erosion. Surface exposure and the reduced organic content of soils also result in altered soil-water relationships and greater variation of soil temperature. The altered soil ecology adversely affects important soil microorganisms such as the rhizobial bacteria responsible for nitrogen fixation in acacias and other leguminous genera. In turn, nutrient regimes are affected and further loss of soil structure results. Altered soil ecology directly eliminates additional plant species and frustrates regenerative processes in others. More losses occur through disruptions in various biological dependency and affinity relationships. Environmental degradation both reduces range-carrying capacity for livestock and affects wildlife populations through habitat modification.
The effects of rangeland degradation often extend well beyond the rangelands themselves. Dust originating in degraded rangelands is transported by dry-season winds to distant areas, causing annoyance, health hazards, and costly interruptions in air and ground traffic. The rapid release of runoff in degraded rangelands following rains contributes greatly to destructive flooding in downstream lowlands, and sediment entering drainage systems in degraded rangelands shortens the useful life of reservoirs and irrigation systems.
Less obvious effects would include the impact of rangeland devegetation on climatic regimes. For example, it is now widely believed that precipitation is strongly influenced by biogeophysical feedback mechanisms (Charney, 1975). Further, it is now believed that precipitation levels are strongly influenced by soil moisture locally released into the atmosphere through evapotranspiration. Hence, reduced vegetative cover and decreased soil moisture would result in reduced local precipitation. Finally, losses of vegetation affect surface roughness in the atmospheric boundary layer. Surface roughness contributes to the destabilization of moisture-laden air masses, thus encouraging precipitation. Devegetation also reduces carbon dioxide uptake in the planetary biomass. The greater concentration of carbon dioxide in the atmosphere contributes to global warming, causing changes in
atmospheric circulation and rising sea levels through the melting of continental ice sheets.
Historically, attempts to transfer experience gained in the management of North American or European rangelands to the management of tropical and subtropical rangelands have been unsuccessful (Heady and Heady, 1982). In managing tropical and subtropical rangelands, it is important to characterize carefully the physical system being managed in order to better understand the biological potential of the system and ensure that critical ecological processes are restored and maintained. It is equally important to relate efforts in range improvement to the needs, knowledge, adaptations, and capabilities of local populations, as well as to the broader economic and political contexts of such efforts. The widespread belief that pastoral systems are simply artifacts of the past requires reexamination. The view that range improvement in the tropics and subtropics should focus narrowly on the increased per unit productivity of selected forms of livestock, usually cattle, at the expense of the biological diversity basic to the maintenance of local coping strategies and economies should similarly be reexamined.
Traditional tropical forest technologies—cyclic agroforestry, inter-cropping, and home gardens—promote the conservation of biodiversity and offer insights into useful ecological associations. Local people are often excellent resource managers when they are allowed to manage their own resources for their own benefits. Development tends to encourage them to change their traditional ways of life and often to become more exploitation minded, including converting very complex multispecies agroecosystems into monocultures, which often encourages overexploitation of the system. The key research problem is to identify how the more complex traditional systems can be adapted to modern needs, for example, to support a growing population and use less labor-intensive methods of cultivation while still retaining the biological diversity of both the agroecosystems and the surrounding lands.
RESEARCH ON LOCAL KNOWLEDGE
As noted above, the cultures that developed and maintained local knowledge, and the systems that sustained productivity and diversity over many generations, are rapidly changing. Local knowledge is being displaced by technologies that have not demonstrated their
sustainability or their long-term contributions to society. As development agencies seek to understand the traditional forms of management, research must seek to identify the nature of this productivity and sustainability from the perspective of the cultures in which they evolved, and it must do so before this knowledge is lost.
Fundamentally, research should provide information on local resource use practices. We need to compile information on local populations and particular resource management patterns (including the uses of flora and fauna) that exemplify sustainable relationships between people and the environment. An inventory of this knowledge should be compiled, highlighting specific features that can contribute to conservation and development, with special attention given to the identification of endangered local resource use patterns. Educational agencies should be assisted in introducing elements of local conservation knowledge and practice into appropriate curricula, and educational activities should be undertaken to encourage interest in traditional knowledge and its practitioners. To the extent possible, the value of local management systems should be demonstrated by indigenous people themselves.
Research should promote the application of local knowledge to modern resource management, and vice versa. An exchange of knowledge and methodologies would foster greater mutual understanding between indigenous peoples and conservation scientists or managers. To facilitate such consultation, indigenous peoples may need training in the approach and techniques of conservation science. Scientific investigators and researchers should include indigenous coinvestigators in all phases of their research design and implementation, with the objective of establishing networks for the long-term exchange of information and learning. Financial and technical resources should be made available to enable indigenous people to conduct their own research. The aim should be to create an indigenous scientific community that includes both locally evolved and externally acquired expertise, skills, and procedures.
Based on this information, development agencies would be able to design projects that benefit indigenous people and that benefit from local knowledge. The agencies should identify opportunities to demonstrate how local knowledge can be combined with science in designing systems for sustainable resource use and developing such projects for external funding. Based on a review of development projects that have involved indigenous people, a workshop should bring together experts to develop guidelines that agencies can use to enhance the design, implementation, and monitoring of their development projects.
To promote the idea that local knowledge and practices (such as customary law) remain relevant for contemporary natural resource management, especially in terms of the scientific insights they provide,
the rationale for examining local knowledge and practices should be communicated to professional groups. Traditional land tenure arrangements should serve as a basis for planning and executing conservation projects, as well as projects more directly concerned with food and materials production. Marine conservation and inshore fisheries development programs should be based on established rights and tenure systems, and should incorporate local ecological and management knowledge. Where traditional tenure systems appear to be inadequate for markedly changed conditions (in the case of greatly increased human population or resource degradation), new systems should adapt the best features of the old.
Priority Groups for Research
There are, at minimum, hundreds of different ecosystem types, thousands of ethnic groups, and between 10 and 25 million species in the developing nations. Clearly, studying all existing or possible resource use patterns, traditions, combinations, and relationships is impossible. A selection of people and places is required. Of highest priority are those use patterns and knowledge systems that are changing most rapidly or disappearing. The following are recommended for closer study:
Foragers and collectors, particularly tropical forest dwellers and desert nomadic pastoralists. These distinctive cultures are eroding as a result of encroachment and resettlement of people from heavily populated areas. Their knowledge is particularly important in that they not only forage and collect, but manage forest vegetation in subtle, almost invisible, and usually ignored patterns of resource use. They have acquired a great deal of information about medicinals and many other plant and animal uses, and little Western scientific information exists on the sustainable use of these areas.
Coastal fisherman, strand foragers, and small island villagers, such as the Orang Laut and Moken in Asia. These are the marine analogues of the forest foragers, their societies having evolved to take advantage of aquatic resources. They too are experiencing rapid resettlement, with consequent loss of their specialized knowledge. The often unique nature of coral reef and island ecosystems in the tropics makes this group of especial importance.
Subsistence agriculturalists raising nonconventional staple crops and animals, as well as subsistence agriculturalists raising local cultivars and breeds of conventional crops and animals. There are still many groups—for example, the Senoi villages in Peninsular Malaysia, the Haya in the Usumbura mountains of Tanzania, the Aymara of the altiplano around Lake Titicaca in Peru and Bolivia, and many Amazon
groups as well as those in the Andean highlands (NRC, 1989)—that grow nonconventional crops, indigenous cereals, legumes and tubers on a small scale, which are better suited than exotic crops to local environmental conditions. Although the traditional resource use patterns of such groups are not changing as rapidly as some of those mentioned earlier, the economic pressure to produce only plant and animal varieties marketed internationally is rapidly eroding the genetic base of many important world food commodities. The diversity of genetic stocks, species composition, and management methods that characterizes and has long sustained traditional agricultural systems is being lost.
Groups that have successfully adapted traditional technologies and resource use patterns in developing market opportunities, such as the ribereños of the Peruvian Amazon.
A Cultural Research Agenda
Social science research should improve our understanding of the relationship between biological diversity and local knowledge bases and of the activities that determine resource use, and should translate this understanding into policy and program tools. The central question that social sciences can help illuminate in the effort to conserve biodiversity is, How do local people affect the biological diversity of the ecosystems they inhabit? More specifically,
How do local people use ecological resources, and why?
What effects do these uses have on biological diversity?
What changes in the conditions of local people promote patterns of use that deplete or conserve biological diversity?
Together, these questions provide a conceptual framework for more detailed investigations of the social and cultural aspects of biological diversity and its conservation.
Use of Resources—Social Concepts of Biodiversity
Research on the relationship among cultural patterns, economic bases, social activities, and the use of natural resources provides us with baseline data with which to interpret impacts, positive and negative, on the biological diversity of a given ecosystem. To understand more fully how and why local people use resources, researchers should do the following:
Record the local knowledge system, including the species, communities, or ecosystems used; the quantity and type of products obtained;
the management systems employed; and reasons for choosing particular species.
Determine how farmers, foragers, and other local men and women conceive of biodiversity, conservation, sustainability, and genetic erosion, and the historical or cultural basis of their views.
Identify conservation practices used, the behavioral basis for those practices, and the role of social institutions (such as kin groups, religion, or belief systems) in the employment of these practices.
Describe the theories, implicit or embedded, that people use to guide modification of ecosystems to achieve certain goals.
Determine the scale dependence of local technologies, the degree to which they can be employed on a broader scale, and the modifications and cautions that must accompany such applications.
Devise simple methods for assessing the genetic diversity of local crops and animals, and means by which this information can be used to add to local understanding of genetic variability.
Effects of Land or Resource Tenure and Uses on Biological Diversity
Research on the effect of traditional and nontraditional resource use on biological diversity builds on the baseline information outlined above to help us understand the relationship between social actions and ecological consequences. To understand more fully this relationship, researchers should:
Determine how resource use patterns may have evolved prior to the introduction of recent external influences, and the degree to which this altered and formed the diversity characteristic of the locale;
Examine the penetration of external farming technologies into local agricultural systems and assess the impact of these technologies on decisions about the conservation or loss of local cultivars and management tools;
Determine how the degree of landscape fragmentation affects the organization and content of local knowledge; and
Assess the degree to which local institutions and belief systems have or have not served as effective agents for conservation of biodiversity.
Impact of Changing Conditions
Research on the changing conditions of local people,* and the effect of these changes on resource use patterns, is necessary if we are to
understand more fully the basic causes and consequences of biodiversity loss. This research essentially involves the relationship between local actions and supralocal influences, and the impact of that changing relationship on the status of biodiversity. To understand more fully the dynamics of this relationship, researchers should:
Identify mechanisms within local knowledge or decision-making systems that allow local peoples to react and adapt to exogenous factors;
Characterize the relationship between degree of local control of resources and conservation of biodiversity, and how such relationships can further conservation goals (e.g., by encouraging the observance of reserve boundaries through social incentives);
Investigate the structure and function of local organizations whose decisions affect biodiversity and determine how local organizations that support the conservation of biodiversity can be strengthened; and
Describe the social factors that should be considered when establishing reserves in areas that are inhabited or adjacent to inhabited areas.
Social Valuation of Biodiversity at the National Level
At this level, the following steps must be taken:
Evaluate the adequacy of the institutional infrastructure charged with managing natural resources and implementing conservation programs.
Describe the status of communication between national institutions charged with implementation of conservation programs and local institutions involved in the use of biological resources.
Identify how the objectives of agricultural and environmental officers in development agencies diverge, and the effect of this divergence on conservation programs.
Identify local and national institutions that could be used to enhance the national status of local knowledge. Understand how local institutions deal with, or are altered by, the massive shifts in landscape use resulting from large development projects.
Determine how national and international conservation priorities can be reconciled when they are at odds (Peru, for example, may want to concentrate on saving high-elevation crop germ plasm, whereas the World Wildlife Fund will give higher priority to the Peruvian Amazon).
Determine how national goals of increasing foreign exchange through exploitation of the natural resource base can be reconciled with local goals of using resources in a sustainable manner.
Determine why development agencies, national governments, urban elites, and educational systems devalue local knowledge, and identify measures that can be taken to reverse this situation.
Describe the structural and philosophical changes that would allow development agencies to use local knowledge more effectively in development activities.
Identify and characterize local and national institutions that currently record local knowledge and are most appropriate for recording and disseminating it.
Determine the intellectual property rights issues associated with local knowledge and whether local or national institutions can ensure these rights.