When it rains and drylands bloom, one realises the remarkable diversity of living organisms they harbour. Long overlooked, this diversity is crucial to the food security of a large share of the world’s population. Drylands cover about 41 % of the earth’s land surface. More than two-thirds of their area lie in developing countries, where around 90 % of the two billion dryland inhabitants live – about a quarter of the world’s population. Drylands encompass savannah woodlands, grassland, deserts and other areas with inconsistent rainfall, often high temperatures, and great seasonal and spatial variations of the fauna and flora.
Dryland – inhabitants, development and climate change
Many dryland inhabitants are poor and depend on local plants and animals for their survival, food and income. Their century-old food production and livelihood strategies optimize the sustainable use of available resources. The world’s 120 million pastoralists have especially well adapted to dryland conditions. The breeds they have developed and their mobile herding strategies enable them to produce food in areas too dry for cropping.
But land-use patterns are changing rapidly. Rising populations, new technologies, education, government policies, trade and other factors promote the intensification and expansion of cropping and livestock keeping. Overuse of resources and inappropriate land use lead to degraded soils, desertification and the loss of biodiversity. The impacts are felt especially in the 50 poorest countries of this world.
Climate change is expected to aggravate the situation and enhance the frequency and extent of extreme weathers, floods and droughts. This will threaten the existence of many of the poor whose livelihoods are closely intertwined with the diversity they have nurtured for centuries – and that holds many potential solutions for the adaptation to climate change.
Drylands: Stores of agrobiodiversity
Drylands harbor food crops, large numbers of adapted breeds of goats, sheep, cattle, equines and camelids, but also soil bacteria, yeasts and other organisms involved in agriculture and food production. The plants and animals in drylands are well adapted to drought, variable rainfall and harsh environment. They do not need to drink every day and in extreme situations they can survive up to a fortnight without water. The adaptive traits of dryland organisms will be of growing importance for coping with the impacts of climate change.
The rich diversity has evolved over thousands of years, shaped by ecological factors and human activities. Summarized under the term “agrobiodiversity”, the plants, animals and micro-organisms relevant to food and agriculture cannot be separated from the people who have created them through the sustainable use of selected resources and the management of ecological and biodiversity and reduce agricultural and ecological risks. Ensuring that communities adequately benefit from the use and commercialization of the resources they steward can provide important incentives for the conservation of these resources.
The value of dryland agrobiodiversity
The contribution of traditional dryland systems and their agrobiodiversity to food production and food security is enormous. Worldwide, about 800 million farmers in drylands depend on dryland cereals and legumes, together with vegetable and scarce food supply, traditional plant varieties re often life savers. In some areas, adapted livestock can be the only sustainable option for food production.
Economic figures mostly capture market values of single production strategies and therefore do not reflect the true value of the complex dryland agrobiodiversity. Nevertheless, they highlight that its economic contribution is substantial.
In Sudan, Senegal and Niger, pastoralism contributes about 80 % to the gross domestic product. In Ethiopia, pastoralists produce about 65 % of the national milk output – not counting pastoralists’ own consumption, which is estimated at 77 % of the total production. In India, more than 45 % of agricultural production and nearly 80 % of coarse cereal outputs stem from drylands.
Threats to agrobiodiversity
Long dismissed as “fragile”, drylands are in fact remarkably resilient: for example, the natural vegetation can quickly recover from long periods of drought or from heavy grazing. Nevertheless, agrobiodiversity in drylands is subject to various threats:
- Rising human populations, resulting in increasing pressure on already scarce water, trees and cultivable land, and conflict over such resources
- Inappropriate farming techniques, resulting in falling water tables, monocultures, soil erosion, the formation of hardpans, rising soil salinity and pollution of groundwater and surface water
- Land-use change from grazing to cropping, afforestation with inappropriate species, fencing and land-grabbing or expropriation by powerful locals or outside investors, often illegally and in areas that cannot reliably support crops
- Attempts at conservation, including restrictions on the movement of pastoralists, and designation as wildlife reserves regardless of traditional uses and local peoples’ rights
- The marginalization of traditional communities that manage dryland resources, and the loss of traditional management mechanisms and indigenous knowledge
- Climate change, reflected in rising temperatures, changed rainfall amounts and patterns, frequent drought and destructive floods
Combating these threats and minimizing their impacts is urgent to avoid dryland communities – already among the poorest in this world – from bearing a disproportionate share of the costs
Dryland people hold the key for agrobiodiversity conservation
Building on and strengthening peoples’ sustainable use of natural and domesticated resources is one of the most promoting routes to conserving dryland agrobiodiversity. Therefore it is important to revive traditional crops, livestock and management practices as developing and marketing specialty products. Furthermore the benefit should be shared equitable and fair. As Many local people have come to believe that their local crop varieties and animal breeds are obsolete and backwards, empowerment, capacity building and awareness rising should be pushed.
Healthy dryland ecosystems and agrobiodiversity are essential for dryland communities to overcome their poverty. A major challenge is how to facilitate agricultural growth without endangering the resource base. Communities are the experts but need support and conductive conditions to continue their sustainable use and conservation of dryland agrobiodiversity and get out of poverty.
References
von Lossau, Annette (2011): 
