This is the VOA Special English Agriculture Report.
especially in developing countries, are often criticized for cutting down forests.
But a new study suggests that many farmers recognize the value in keeping
using satellite images found at least ten percent tree cover on more than one
billion hectares of farmland. That is almost half the farmland in the world.
World Agroforestry Center in Kenya led the study. The findings were reported
last week in Nairobi at the second World Congress of Agroforestry.
Earlier estimates were much lower but incomplete.
The authors of the new study say it may still underestimate the true extent
study found the most tree cover in South America. Next comes Africa south of
the Sahara, followed by Southeast Asia. North Africa and West Asia have the
The study found that climate conditions alone could
not explain the amount of tree cover in different areas. Nor could the size of
nearby populations, meaning people and trees can live together.
are areas with few trees but also few people, and areas with many trees and
many people. The findings suggest that things like land rights, markets or
government policies can influence tree planting and protection.
Dennis Garrity heads the World
Agroforestry Center. He says farmers are acting on their own to protect and
plant trees. The problem, he says, is that policy makers and planners have been
slow to recognize this and to support such efforts.
The satellite images may not show
what the farmers are using the trees for, but trees provide nuts, fruit, wood
and other products. They provide windbreaks and shade from the sun. They also help
prevent soil loss and protect water supplies. Even under drought conditions,
trees can often provide food and a way to earn money until the next growing season.
The important thing, says one
expert, is to find the right tree for the right place for the right use.
act as natural fertilizers. They take nitrogen out of the air and put it in the
soil. Scientists at the agroforestry center say the use of fertilizer trees can
reduce the need for chemical nitrogen by up to three-fourths. And they say it
can double or triple crop production.
also capture carbon dioxide, a gas linked to climate change.
Maathai is a Kenyan environmentalist and Nobel Peace Prize winner. She says the
study shows that trees are critical to agricultural production everywhere.
And that's the VOA
Special English Agriculture Report, written by Jerilyn Watson. I'm Jim Tedder.