Agricultural biodiversity of all food species is a vital sub-set of general biodiversity, highly threatened by globalisation of food markets and tastes, intellectual property systems and the spread of unsustainable industrial food production, but it provides the basis of the food security and livelihood security of billions of people and the development of all food production, including for industrial agriculture and for the biotechnology (Life) industries. It is the first link in the food chain, developed and safeguarded by farmers, herders and fishers throughout the world.
Although the term "agricultural biodiversity" is relatively new - it has come into wide use in recent years as evidenced by bibliographic references - the concept itself is quite old. It is the result of the careful selection and inventive developments of farmers, herders and fishers over millennia. Agricultural biodiversity is a vital sub-set of biodiversity. It is a creation of humankind whose food and livelihood security depend on the sustained management of those diverse biological resources that are important for food and agriculture. Agricultural biodiversity, also known as agrobiodiversity or the genetic resources for food and agriculture, includes:
Agricultural biodiversity has spatial, temporal and scale dimensions especially at agro-ecosystem levels. These agro-ecosystems - ecosystems that are used for agriculture - are determined by three sets of factors: the genetic resources, the physical environment and the human management practices. There are virtually no ecosystems in the world that are "natural" in the sense of having escaped human influence. Most ecosystems have been to some extent modified or cultivated by human activity for the production of food and income and for livelihood security.
Agro-ecosystems may be identified at different levels or scales, for instance, a field/crop/ herd/pond, a farming system, a land-use system or a watershed. These can be aggregated to form a hierarchy of agro-ecosystems. Ecological processes can also be identified at different levels and scales. Valuable ecological processes that result from the interactions between species and between species and the environment include, inter alia, biochemical recycling, the maintenance of soil fertility and water quality and climate regulation (e.g. micro-climates caused by different types and density of vegetation). Moreover, the interaction between the environment, genetic resources and management practices determines the evolutionary process, which may involve, for instance, introgression from wild relatives, hybridization between cultivars, mutations, and natural and human selections. These result in genetic material (farmers' crop varieties or animal breeds) that is well adapted to local abiotic and biotic environmental variation.
So, agricultural biodiversity is not only the result of human activity but human life is dependent on it not just for the immediate provision of food and other goods, but for the maintenance of areas of land that will sustain production and for the maintenance of the wider environment.
Agro-ecosystems comprise polycultures, monocultures, and mixed systems, including crop-livestock systems (rice - fish), agroforestry, agro-silvo-pastoral systems, aquaculture as well as rangelands, pastures and fallow lands. Their interactions with human activities, including socio-economic activity and sociocultural socio-cultural diversity, are determinant. Some of the key functions for maintaining stable, robust, productive and sustainable agro-ecosystems may include the following:
This was discussed at an international Agricultural Biodiversity workshop organised by the Food and Agriculture Organization of the United Nations (FAO) and the Convention on Biological Diversity (CBD) where the multiple dimensions of agricultural biodiversity were also summarised as providing for:
The variety and variability of animals, plants and micro-organisms used directly or indirectly for food and agriculture (including, in the FAO definition, crops, livestock, forestry and fisheries). It comprises the diversity of genetic resources (varieties, breeds, etc.) and species used for food, fodder, fibre, fuel and pharmaceuticals. It also includes the diversity of non-harvested species that support production (e.g. soil micro-organisms, predators, pollinators and so on) and those in the wider environment that support agro-ecosystems (agricultural, pastoral, forest and aquatic), as well as the diversity of the agro-ecosystems themselves.
It has also been defined as:
Agricultural biodiversity encompasses the variety and variability of animals, plants and micro-organisms which are necessary to sustain key functions of the agro-ecosystem, its structure and processes for, and in support of, food production and food security. (FAO, 1999)
These locally diverse food production systems are under threat and, with them, the accompanying local knowledge, culture and skills of the food producers. With this decline, agricultural biodiversity is disappearing and the scale of loss is extensive and with the disappearance of harvested species, varieties and breeds goes a wide range of unharvested species.
The genetic erosion of agricultural biodiversity is also exacerbated by the loss of forest cover, coastal wetlands and other 'wild' uncultivated areas, and the destruction of the aquatic environment. This leads to losses of 'wild' relatives, important for the development of biodiversity, and losses of 'wild' foods essential for food provision, particularly in times of crisis.
There are many causes of this decline, which has been accelerating throughout the 20th century in parallel with the demands of an increasing population and greater competition for natural resources. The principal underlying causes include:
As a consequence there has been:
Variety replacement is the main cause of losses. The replacement of local varieties or landraces by improved and/or exotic varieties and species is reported to be the major cause of genetic erosion around the world. It is also cited as the major cause of genetic erosion in all regions except Africa. Examples are mentioned in 81 Country Reports, of which a number are highlighted below. A survey of farm households in the Republic of Korea showed that of 14 crops cultivated in home gardens, an average of only 26% of the landraces cultivated there in 1985 were still present in 1993. The retention rate did not exceed 50% for any crop, and for two crops it was zero. These results are disturbing as such home gardens have traditionally been important conservation sites, especially for vegetable crops.103 In China, in 1949, nearly 10,000 wheat varieties were used in production. By the 1970s, only about 1,000 varieties remained in use. Statistics from the 1950s show that local varieties accounted for 81% of production, locally produced improved varieties made up 15% and introduced varieties 4%. By the 1970s, these figures had changed drastically; locally produced improved varieties accounted for 91% of production, introduced varieties 4% and local varieties only 5%. (FAO 1996, 1998)