"While government officials and technical experts are often considered as key decision-makers, in the case of in situ conservation and use of agricultural biodiversity, the ultimate decision-makers are the farmers and rural communities that use and depend upon biological resources for their income and survival." (CGIAR, 1996)
Throughout the world, and more especially in developing countries, wild plants make an important contribution to the life of local communities. They play a significant part in a wide range of agricultural systems as a source of wild foods and fuelwood, and they have an important socio-economic role through their use in medicines, dyes, poisons, shelter, fibres and religious and cultural ceremonies. Yet little systematic knowledge has been gathered on the uses of wild plants and they tend to be ignored in considerations of farming systems by extension workers, policy-makers and economists. Wild resources in general are often ignored and receive little recognition from the development community (Scoones, Melnyk and Pretty, 1992). The reasons for this neglect centre around:
In most societies the use of wild plants forms part of traditional or indigenous systems of knowledge and practice that have developed and accumulated over generations. These systems form the basis of local-level decision-making in agriculture, food production, human and animal health and natural resource management (Slikkerveer, 1994).
The term "wild" when applied to plants or plant species refers to those that grow spontaneously in self-maintaining populations in natural or semi-natural ecosystems and can exist independently of direct human action. The term is contrasted with "cultivated" or "domesticated" plants or plant species that have arisen through human action, such as selection or breeding, and that depend on management for their continued existence.
In practice the distinction is not an easy one to make, as there is a complete spectrum between completely wild and completely domesticated species, depending on the degree of human intervention or management involved.
Domestication grew out of food gathering, which almost imperceptibly led to cultivation. It is a long and complex process, and many plants are found in various stages of domestication as a result of human selection, however slight. Many species, especially trees, are widely planted, although genetically and culturally in a nearly wild state. In Borneo, for example, mangoes (Mangifera spp.) have a long history of semi-cultivation along rivers. Trees whose fruits are preferred are planted in the vicinity of houses. At a later stage, trade or exchange of fruit or seedlings occurs among villages.
A child collects wild fruit from from a tree in Cambodia
A common situation is where plants grow wild in ecosystems that have themselves been "domesticated". For example, many of the plant species of the Mayan home gardens are native wild species of the Yucatán peninsula, mainly tall trees that are left to stand when the forest is cut down to establish a new home garden. Moreover, these plants may grow spontaneously from seeds or other propagules that are either already present in the home garden or naturally dispersed in the home garden from the nearby forest or from neighbouring home gardens. Likewise, in the highlands of Irian Jaya, occupied by people of the Mek group, a pygmaean people with a Neolithic culture, when new garden land was required, an area of secondary forest, and also sometimes primary forest, was cleared for shifting cultivation. All the young trees were removed with the exception of small groups of Pandanus spp. whose fruits and leaves were used. Pandanus spp. are not planted but always collected from the forest. Leaving behind forms with particular characteristics (e.g. large fruits) can be regarded as a first stage of domestication.
Similarly, in many parts of Africa "farm trees" are found scattered through areas of cultivated land within and near farm fields. These trees are managed, protected and harvested by farmers to provide fuelwood, fodder, poles for construction and edible fruits and nuts. In the Sahel, with its sandy soils of low fertility, scattered Acacia albida trees in millet or sorghum fields increase crop yields up to two and a half times over those obtained in open fields.
In fact humans have been using forests intensively for many thousands of years and their management of forest resources has resulted in the domestication of the landscape, a concept introduced to describe the case of the Australian Aborigines. The term "domiculture" was introduced to describe this kind of domestication as opposed to the conventional genetic modification of plants through selection and breeding.
Wild plants may be transferred from forests or other ecosystems to trailsides or near human habitations as well as into fields so that they are readily available and easily collected. This minimal form of domestication seems quite common and is practised by the Kayapó Indians of South America (Posey, 1985). The stages in the process of co-domestication of forests and tree species that has resulted from interactions between local communities and forests are illustrated in Figure 1.
Many species that are domesticated and widely cultivated, such as Pistacia vera, the pistachio, are still extensively collected from the wild. Much of the market demand for rocket (Eruca sativa and Diplotaxis spp.) is met by harvesting the plant from the wild, and wild types can be easily spotted in Italian vegetable markets (Bianco, 1995). Other examples are some medicinal or aromatic plants such as oregano, sage, thyme and African stinkwood (Prunus africana). Many species that have been domesticated escape from cultivation and have become naturalized. Weedy forms, cultivated and semi-cultivated plants exist side by side. Thus there is a whole range of different situations ranging from completely wild, to semi-domesticated through selection, to fully domesticated through selection and breeding, to escaped from cultivation, to naturalized.
Some social anthropologists insist that terms such as "wild" and "domesticated" are culturally specific and would, for example, have quite different meanings to a European farmer and a Kayapó Indian, as in the case mentioned above (Posey, 1992). On the other hand, it can be argued that the special characteristics and genetic basis of domestication can be understood without acquiring a detailed knowledge of the Kayapó concept.
If it is also considered that most of the terrestrial world is in one sense or another an agro-ecosystem, it is difficult to maintain a strict separation between wild and cultivated plants. This book covers examples taken from all parts of this spectrum, although emphasis is given in later chapters to those species that have potential for formal cultivation following selection, breeding and agronomic development.
Throughout the world, many thousands of plant species are used in human activities and can be considered resources. About 5 000 have been cultivated at one time or another, but of the 250 000 to 300 000 known higher plant species, only a few hundred species have been fully domesticated and enter world trade.
Only 103 species of food plants contribute 90 percent of national per caput supplies, while 20 to 30 of these species are regarded as the staples that supply most of human nutrition needs. On the other hand, thousands of species grown locally are scarcely or only partially domesticated and many thousands more are gathered from the wild. Not surprisingly, most of the partially domesticated or wild-collected species are found in the tropics. For example, the Plant Resources of South-East Asia (PROSEA) project records nearly 6 000 species in its basic list of species (some of them exotic) used by humankind in that region, and assuming similar levels in other tropical regions, a figure of 18 000 to 25 000 species can be extrapolated for the tropics as a whole. In addition, several thousand plant species are used in human activities in the Mediterranean and temperate regions of the world. These figures exclude most of the 25 000 species that are estimated to have been used or are still in use as herbal medicines in various parts of the world, especially China, tropical Asia, the Indian subcontinent, Africa and Central and South America, and the many thousands of species grown as ornamentals in parks and in public and private gardens and in the horticultural trade.
Wild species used by humans occur in all biogeographical regions and habitat types. In each region communities have learned to make use of the plant diversity, no matter how harsh the environment. For example, several million people depend on the diverse vegetation - forest, woodland, thickets, grasslands and swamps - in the Maputaland-Pondoland region of South Africa for their livelihood, including cattle raising, food, health care, fuel and shelter. As many as 900 species with specific medicinal uses have been recorded and the region is a major source of material for the large herbal trade of southern Africa. Even in montane regions such as the Andes, specialized systems have developed for the exploitation of wild species. In the Uttar Pradesh hills, India, a wide range of wild foods belonging to about 480 species are consumed. In desert and arid zones, wild species have a critical role in pastoral and agro-pastoral communities that depend to a large extent on the availability of natural vegetation and its component species for the grazing or browsing of their domesticated animals as well as for other domestic uses.
Tropical forests have long been recognized as housing a large percentage of the planet's biodiversity, and the plant species they contain are a major source of food and numerous other products. It has been estimated that in Amazonia over 50 percent of the rural population depends on forestry activities, including extractivism, for survival. Globally hundreds of millions of tribal people inhabit tropical forests and use wild species or products derived from them as a significant part of their household economy, but the details vary enormously within areas, among areas and among regions.
A young boy in Senegal learns to write on a wooden tablet from Balanites aegyptiaca, a dominant tree species in the region which is used to produce writing tablets and ink (from the ashes); its fruit is also commercialized and much appreciated
The biodiversity of most of the wild species dealt with in this book is usually poorly studied. Even their identification and classification are often unsatisfactory, leading to considerable confusion when the plants or their products are traded. Even less is known about their detailed distribution, the extent, size and diversity of their populations, their breeding behaviour, pollination mechanisms and so on. Since most of the species under consideration have never been cultivated or are at most semi-domesticated on a local scale, their most basic agronomy is virtually unknown and it is necessary to depend on knowledge developed over long periods by local farming societies. It is essential that this local knowledge, which is itself an important resource, be recorded and made available for future generations.
The coming into force of the Convention on Biological Diversity in 1993 placed biodiversity firmly on the political agenda and required the parties to consider ways of inventorying and monitoring their biological resources and to take the necessary steps to ensure their conservation, their sustainable use and equitable sharing of the benefits derived from them. The Convention on Biological Diversity specifically mentions wild species such as crop relatives and those of medicinal and agricultural value in the indicative list of categories of the components of biological diversity to be identified and monitored (Convention on Biological Diversity, 1994). It also calls for measures to respect, preserve and maintain knowledge, innovations and practices of indigenous and local communities for conserving and sustainably using biodiversity.
Also important is Decision III/11 of the Conference of the Parties to the Convention on Biological Diversity on a multiyear programme of activities on agricultural biological diversity, which covers a number of thematic areas including wildlife and wild sources of food.
Another important event was the International Technical Conference on Plant Genetic Resources held in Leipzig, Germany from 17 to 23 June 1996. In the Global plan of action for the conservation and sustainable utilization of plant genetic resources for food and agriculture endorsed by governments, the promotion of the development and commercialization of underutilized crops and species and in situ conservation of wild plants for food production (in the broad sense) were among the priorities listed (FAO, 1996c).
This book aims to raise awareness of the role of wild plants in many farming systems, providing examples from a range of different systems around the world. It also describes the major areas in which wild plants contribute to farm household incomes and the welfare of the local people and assesses the potential for future development. The book also points out the constraints faced by farmers in attempting to enhance the use of wild plants and proposes ways in which these constraints may be overcome through improved methods and policy.