Using protected areas to secure our food
Wild plants continue to supply new medicinal drugs and contain a reservoir of useful genes that can confer desirable traits for cultivated crops.
But the chances of discovering novel traits or uses for species are decreasing – just as we are increasing our knowledge of plant species and functions, so are our activities leading to their destruction.
Diversity, the foundation of our food security
The 2004 edition of IUCN’s Red List, for example, found that the numbers of threatened species are increasing across almost all the major taxonomic groups with the main pressures coming from habitat loss, competition from introduced species and over-exploitation, with human-induced climate change becoming an increasingly significant problem.
Diversity, the foundation of our food security, is also decreasing within cultivated crops.
The Food and Agriculture Organisation of the United Nations (FAO) estimates that about 75% of the genetic diversity of agricultural crops has been lost in the last century due to the widespread abandonment of genetically diverse traditional crops in favour of genetically uniform modern crop varieties.
Uniformity is replacing diversity
The primary reason is that plant breeders throughout the world are engaged in developing commercial varieties of crop plants.
This involves the replacement of the generally genetically diverse, lower yielding, locally adapted crops grown traditionally, with generally higher yielding varieties deliberately bred for genetic uniformity. Thus uniformity is replacing diversity.
These same plant breeders paradoxically are dependent upon the availability of a pool of diverse genetic material for success in their work, but are unwittingly causing the genetic erosion of the very plant diversity that they themselves need for future breeding.
9 crops make up 75% of our plant diet
The Green Revolution of the 1950s spread high yielding, disease and pest resistant new varieties across the developing world; by 1990 they covered half of all wheat lands and more than half of all rice lands – a total of some 115 million ha.
As yields increased, the diversity of crops and varieties has decreased, reducing potential for adaptation to changing conditions.
Today, it is widely stated that just 9 crops (wheat, rice, maize, barley, sorghum/millet, potato, sweet potato/yam, sugar cane and soybean) account for over 75% of the plant kingdom’s contribution to human dietary energy.
There are however still many millions of small farmers, particularly in marginal agricultural environments unsuitable for modern varieties, who practice traditional agriculture by cultivating community-bred crops (or ‘landraces’) produced through cycles of sowing, harvesting and selection of seed for planting over many generations.
The genetic diversity represented in these landraces remains a vital resource for global food security and economic stability.
An equally threatened global agro-biodiverse resource is the reservoir of genetic diversity found in the wild species that are closely related to crops, the so-called crop wild relatives (CWR).
Farmers have for millennia benefited from the natural crossing between crops and their wild relatives introgressing beneficial traits into the crop that enable it successfully to counter evolving pest and diseases and environmental changes.
Contemporary breeders are increasingly searching the gene pool of crop relatives for these desirable traits.
Both landraces and CWR thus serve as the world’s repositories of crop genetic diversity and represent a vital source of genes that can ensure future food security.
Their importance is increasing as human population growth and climate change alter environmental conditions and thus force the pace of agricultural change.
This report reviews the importance, conservation and use of the genetic diversity found in CWR and landraces, and considers options for their conservation when associated with protected areas.
A crop cultivar that evolved with and has been genetically improved by traditional agriculturalists, but has not been directly influenced by modern breeding practices.
The permanent incorporation of genes from one set of differentiated populations (species, subspecies, races and so on) into another.
A variety of a plant produced and maintained by horticultural techniques and not normally found in wild populations.
Crop Wild Relative - a wild plant with a genetic relation to a cultivated crop.
Main findings of the report
- Many centres of diversity of our principal cultivated plants are poorly protected.
- The role of protected areas in conserving crop genetic diversity could be greatly increased by better understanding of this issue within protected area organisations.
- The promotion of the conservation of crop genetic diversity within existing protected areas may further enhance the public perception of protected areas and help to ensure longer term site security.
- There are already a few protected areas which are being managed specifically to retain landraces and CWR and there are many more protected areas that are known to contain populations essential to the conservation of plant genetic resources.
- By conserving locally important landraces, protected areas can contribute to food security, especially for the poorest people.