Drylands forests and agroforestry systems
Agroforestry, and sustainable forest management and restoration, promise hope for world’s threatened drylands.
“We treat dryland trees as if they were inferior to rainforest trees,” claimed Lars Laestadius of the World Resources Institute, at a packed event taking place on the sidelines of UN Food and Agriculture Organization’s Committee on Forestry 2014. “It is as if dryland forest is not a real forest.”
Drylands are defined as those regions where water lost by evaporation or used by plants and animals exceeds the amount of water falling as rain. Dryland forests, of course, are forests located in drylands, and they are usually under stress.
“It is quite obvious that increase in temperature and reduction of rainfall is a challenge for vegetation that exists in conditions that are already very harsh today,” said Eduardo Rojas Briales, Assistant Director General of the Forestry Department, Food and Agriculture Organization (FAO). “Dryland forest is an area that has not received much attention, as the forests are not so impressive. They are small, brown or grey and so they are not so attractive.”
Best estimates show that tropical dry forests occupy 11 percent of the global forest area, yet FAO and UNCCD estimates show that up to two billion people depend on dryland forests and pastures for their food and livelihoods. Dryland regions have been weakened through repeated drought and human intervention, historically and more intensively in the past 50 years. Yet wood from these ecosystems accounts for between 50 and 90 percent of energy used in Africa. For a long-time (and still today), fuelwood has been considered as a free resource, with the only price being the cost of harvesting and transporting it. Open access to resources and the absence of land security have contributed to the destruction of this resource. Unrestricted forest clearance for agriculture and fuelwood has far exceeded the ecosystem’s capacity to regenerate naturally.
“We often hear bad things about drylands,” said Lars Laestadius, “but in many areas, trees are returning to drylands.” In Niger, farmers are managing the natural regeneration of trees in the drylands and had reclaimed over 5 million hectares by 2006. Now this area might well have doubled given the wide adoption of the technique. In a country that had a food deficit in 2011-2012 of 600 000 tonnes per year, the regions with tree cover reported a surplus of food from the crops growing under the trees.
These agroforestry techniques are actually increasing agricultural productivity and food supply. Livestock also depends on the nutritious leaves from the trees for 6 months of the year. The leaves from one mature baobab trees can earn between US$35 and 70 per year, enough to buy a significant quantity of grain.
Agroforestry in the drylands has been neglected by the scientists of the world. The regreening success in Niger was only brought to international attention when the United States Geological Service stated a systematic survey of the region. “How can a five million hectare region have remained undiscovered for so long?” asked Laestadius. “Our monitoring system is not very good. We do not have a good baseline, and if we don’t measure it, we can’t manage it.”
A better system of mapping and monitoring of forest across drylands is needed, and choices are becoming available. Landsat images have serious spatial resolution problems in the drylands, because individual trees could not be resolved. New resources, such as Google Earth, actually show the individual trees. FAO has developed the ‘Collect Earth’ system, which is a Google Earth plugin for forest sampling analysis that even untrained people can use to conduct a field survey actually on screen. The Rapid Land Cover Mapper, developed by the United States Geological Service, maps land use and land cover over large areas and through time, and again can be downloaded for free, and used by non-experts.
Even though dryland forests are so important to the poor local people, a higher percentage of land is degrading or is degraded in drylands. Globally, 30 percent of agricultural land is seen to be degrading, but 46 percent of drylands are degrading.
Monica Petri, from FAO’s Global land degradation assessment progamme (the so-called LADA) team, defined degradation as a decrease of the capacity of an area to produce food and provide ecosystem services. It had an impact on specific users over a specific timeframe. The LADA FAO team has been using 36 global datasets from 1981 to 2003 to develop a system that gives 3-dimensional renderings of land use and land degradation for analysis. The system allows degradation to be viewed on a global scale, highlighting hotspots (increasing degradation) and bright spots (sustainable land management ). It lacks the precision that policymakers need but it does indicate the priority areas that are being affected.
Mostafa Jafari, from the Near East Group of the Low Forest Cover Countries (LFCCs), based in the Islamic Republic of Iran, noted that “Dryland forests and forestry are the most promising way to address problems in LFCCs.” A lack of coordination among sectors, especially at the policy level, was an important barrier to sustainable forest management. Ismail Belen, from the Ministry of Forests and Water of Turkey and President of Silva Mediterranea (the FAO statutory body on Mediterranean Forestry questions), said that Turkey is supporting activities in drylands as means of increasing agricultural productivity and livelihoods for local people.
So how can the problems facing people in the drylands who depend on trees best be addressed? It seems that agroforestry, putting trees on farms and into the landscape, is one way. “Agroforestry is one of the best bets,” said Larwanou Mahamane, Senior Programme Officer of the African Forest Forum. “It is easy to practice, it has many benefits and reduces the impact of human pressure on dry forests.”
Dryland forests face a number of challenges, meeting the demands of humans and animals, recurrent drought with the associated famines, lack of alternative food source for the local people, agricultural encroachment, and the impact of climate change, which is more pronounced than in humid areas.
What can agroforestry systems offer to these challenges? The evidence lies in the impact that agroforestry is clearly having. Farmer-managed natural regeneration of native trees, mixed with cropping, has been highly successful, so much so that it is being adopted in many other countries as farmers see its effects. The Evergreen Agriculture partnership programme, which is being run by the World Agroforestry Centre, has seen 400 percent increases of maize yield when grown under the acacia species Faidherbia albida.
FAO is already recommending tried and tested techniques for dryland systems. “We need a broad-based landscape approach linked with a policy and legal framework, and support should be sustained to resolve the drivers of degradation of dryland forests,” said Mahamane.
New study on trees and resilience in East Africa’s drylands
FAO’s website on drylands: www.fao.org/forestry/aridzone
The FAO event flyer: http://www.fao.org/3/a-mk314e.pdf