While Farmers
Frequently Blamed for Forest Loss, New Study
Shows about Half of Farmlands Worldwide
Have Significant Tree Cover
Scientists Use Detailed
Satellite Images to Reveal the Vital Role
of Trees on One Billion Hectares of Agricultural
Lands in Africa, Asia, the Americas and
Europe
Nairobi, 24 August 2009
- Although agriculture, particularly in
the developing world, is often associated
with massive deforestation, scientists from
the World Agroforestry Centre demonstrated
on Monday, in a study using detailed satellite
imagery, that almost half of all farmed
landscapes worldwide include significant
tree cover.
The findings were announced
at the opening of the 2nd World Congress
of Agroforestry, which is being held in
Nairobi, Kenya this week. The World Agroforestry
Centre is one of 15 centers supported by
the Consultative Group on International
Agricultural Research(CGIAR).
This is the first study
to quantify the extent to which trees are
a vital part of agricultural production
in all regions of the world. It reveals
that on more than 1 billion hectares - which
make up 46 percent of the world's farmlands
and are home to more than half a billion
people - tree cover exceeds 10 percent.
"The area revealed
in this study is twice the size of the Amazon,
and shows that farmers are protecting and
planting trees spontaneously," said
Dennis Garrity, the Centre's Director General.
"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."
From the data presented
in the study, it is not possible in all
cases for the researchers to discern precisely
the products and services that trees are
providing. However, a great deal of previous
agroforestry research has documented a wide
range of uses for trees on farms, including:
fertilizer trees for improving crop yields
and enhancing soil health; fruit trees for
nutrition; fodder trees to feed livestock;
timber and fuelwood trees to provide shelter
and energy; medicinal trees; and trees that
provide global commodities such as coffee,
rubber, nuts, gums and resins. As equally
important on the service side are uses such
as erosion control, water quality and biodiversity.
"If planted systematically
on farms, trees could improve the resiliency
of farmers by providing them with food and
income," said Tony Simons, Deputy Director
General at the World Agroforestry Centre.
"For example, when crops and livestock
fail, trees often withstand drought conditions
and allow people to hold over until the
next season."
"What trees essentially
provide to farmers is choice. Choice of
enterprise, choice of market, choice for
diversification, choice for low labour requirement,
choice for multiple function," Simons
continued. "Developing country farmers
are spoilt for choice. Whilst Western Europe
has some 250 native tree species and North
America has a larger set of 600 trees species
- the developing tropics has a staggering
50,000 tree species to manage and utilize.
The priority is to find the right tree for
the right place for the right use."
Previous estimates for
the amount of farmland devoted to agroforestry
have ranged from as low as 50,000 hectares
to as high as 307 million hectares. But
these estimates were not derived from detailed
remote sensing data as was employed in this
assessment. In this study, scientists were
able to measure the amount of tree cover
on each square kilometer of the world's
22.2 million square kilometers of farmland.
The scientists - who
included researchers from the International
Centre for Integrated Mountain Development
and the Katholieke Universiteit Leuven in
Belgium - found that about 10 million square
kilometers of agricultural land have at
least 10 percent tree cover. That includes
3.2 million square kilometers in South America,
1.9 million in sub-Saharan Africa and 1.3
million in Southeast Asia. According to
the report, "trees are an integral
part of the agricultural landscape in all
regions, except North Africa and West Asia."
Their data also show
that people live with trees in farmed landscapes
in virtually all of Central America, and
in about 80 percent of such landscapes in
Southeast Asia and South America.
The proportion was lower
but still large in sub-Saharan Africa, Europe,
and North America, where trees are a significant
feature on about 40 percent of agricultural
land. The study observes that the extent
of trees in farmland in North America and
Europe is especially impressive, given the
large commercial agricultural sector of
these regions.
"This study offers
convincing evidence that farms and forests
are in no way mutually exclusive, but that
trees are in fact critical to agricultural
production everywhere," said Professor
Wangari Maathai, founder of the Green Belt
Movement. Professor Maathai was awarded
the 2004 Nobel Peace Prize for work that
included planting more than 30 million trees
to provide food, fuel, shelter and income
for Africa's rural poor.
Challenging Commonly
Held Assumptions
Most notably, the researchers
found that globally, there is no consistent
tradeoff "between people and trees."
There are areas with low population and
little tree cover, and areas with lots of
people and lots of trees. And the amount
of tree cover - low or high - could not
be explained solely by climate conditions,
they said.
"This underlines
the importance of other factors," the
study states, such as land tenure rights,
markets, or "other policies and institutions,"
which influence tree planting, retention
and management.
The authors also point
to "documented cases" in which
forests are initially cleared for agriculture
development, but tree cover later returns,
at least partially, as farmers seek to enhance
production by planting useful trees that
can generate income or provide other services,
such as protecting watersheds.
According to experts
at the World Agroforestry Centre, farmers,
particularly in developing countries, would
adopt various agroforestry practices more
rapidly if their trees were included in
international climate change mitigation
schemes now under development.
Trees and Climate Change
Climate change talks
set to take place later this year in Copenhagen
will consider a new strategy focused on
Reduced Emissions from Deforestation and
Forest Degradation (REDD), which could include
payments for carbon captured by trees and
soils. Experts are discussing ways to ensure
that agroforestry is part of the REDD investment
mechanisms. The World Agroforestry Centre
and the United Nations Environment Programme
(UNEP) are developing a standard method
for measuring carbon storage on all types
of landscapes, which could provide a basis
for providing farmers with a financial incentive
to increase tree cover on their farms.
"The data in this
report illustrate that agroforestry will
be critical to efforts aimed at making agriculture
more productive and sustainable in order
to contribute to the alleviation of climate
change," said Garrity. "It is
estimated that further investments in agroforestry
over the next 50 years could remove significant
amounts of carbon dioxide from the atmosphere."
The authors cautioned
that the study may have underestimated the
global extent of tree cover on farmlands.
For example, the researchers used a system
for classifying land as "agriculture
land" that likely missed many areas
- particularly in Africa - so dominated
by tree crops that they were classified
as forests, not "agroforests."
However, scientists anticipate improved
datasets will soon be available that will
do a better job of identifying forested
areas that are being used predominantly
for agriculture purposes.
Notes to Editors:
The World Agroforestry
Centre, based in Nairobi, Kenya, is the
world's leading research institution on
the diverse role trees play in agricultural
landscapes and rural livelihoods. As part
of its work to bring tree-based solutions
to bear on poverty and environmental problems,
centre researchers - working in close collaboration
with national partners - have developed
new technologies, tools and policy recommendations
for increased food security and ecosystem
health. www.worldagroforestry.org
About the CGIAR: The
CGIAR, established in 1971, is a strategic
partnership of countries, international
and regional organizations and private foundations
supporting the work of 15 international
Centers. In collaboration with national
agricultural research systems, civil society
and the private sector, the CGIAR fosters
sustainable agricultural growth through
high-quality science aimed at benefiting
the poor through stronger food security,
better human nutrition and health, higher
incomes and improved management of natural
resources. www.cgiar.org
For more information, contact:
Jeff Haskins
