According to a new study by scientists at the World Forestry Centre in Nairobi, Kenya, we’ve underestimated that amount of trees worldwide that are grown in agricultural areas. Using satellite imagery, the scientists show at the 2nd World Congress of Agroforestry this week in Nairobi that trees cover more than 10 percent of about 10 million square kilometers of farmland — about half of the world’s farms — across North America, Asia, Europe and Africa.
Agroforestry is the practice of integrating trees into agricultural landscapes. A classic example of the ways this benefits farming is shade-tree coffee plantations, where trees provide habitat for birds as well as shade for the coffee plants growing underneath. Trees on farmlands also provide ecosystem services such as fertilizing the landscape, preventing erosion and helping to filter water runoff. Dennis Garrity, the Centre’s Director General, elaborated in a statement:
The area revealed in this study is twice the size of the Amazon, and shows that farmers are protecting and planting trees spontaneously. The problem is that policymakers and planners have been slow to recognize this phenomenon and take advantage of the beneficial effect of planting trees on farms. Trees are providing farmers with everything from carbon sequestration, to nuts and fruits, to windbreaks and erosion control, to fuel for heating and timber for housing. Unless such practices are brought to scale in farming communities worldwide, we will not benefit from the full value trees can bring to livelihoods and landscapes.
Additionally, agricultural landscapes that have higher biodiversity are known to export fewer pollutants into watersheds. The World Forestry Centre advocates that there should be incentives for farmers to cultivate trees that provide such valuable services, and that policy should change to reflect those incentives. Particularly in developing countries, says the Centre, it would help farmers — especially those in developing countries — adopt various agroforestry practices more rapidly if their trees were included in international climate change mitigation schemes now under development.
Read more about agroforestry at the World Agroforestry Centre’s web page.