62 / 311
[
] 63
tree seedlings and birds) of comparable natural forest.
3
These rubber
agroforests are threatened in many places by more profitable land uses,
such as intensified rubber monocultures. The World Agroforestry
Centre has been testing and promoting technologies to improve the
productivity of jungle rubber while maintaining biodiversity.
Agroforestry and climate change
According to the Intergovernmental Panel on Climate Change,
“transformation of degraded agricultural lands to agroforestry has
far greater potential to sequester carbon than any other managed
land use change.”
4
Trees store carbon both above and below ground. Estimates of
the carbon sequestration potential of agroforestry systems vary from
under 100 metric tons of carbon dioxide equivalent (Mt CO
2
e) per
year by 2030
5
to over 2,000 Mt CO
2
e per year over a 30-year period.
6
Agroforestry is also well recognized as a strategy for climate
change adaptation. Expected higher average temperatures, more
severe weather extremes, greater variation in rainfall and shorter
growing seasons will place enormous pressure on agricultural
systems, food production and food prices. Agroforestry helps to
buffer against the impacts of climate change by reducing erosion
and runoff, improving water retention and providing shade.
Research has found that the tree components of agroforestry
systems stabilize the soil against landslides and increase infiltra-
tion rates.
7
This reduces surface flow during the rainy season and
increases groundwater release during the dry season. Agroforestry
has also been shown to redistribute water in the soil profile, provid-
ing annual crops with greater water availability.
8
In Zambia, maize
yields of improved fallow agroforestry systems were, on
average, nearly two times as high as for a pure maize
control.
9
Farmers use trees to diversify risks as they provide
alternative streams of income and increase food security.
This will become all the more important with climate
change. By integrating trees, farmers can decrease their
dependency on a single staple crop or sufficient grass for
their livestock. The diversity of plants used in agrofor-
estry systems can provide multiple harvests at different
times of the year.
Agroforestry and combating desertification
Agroforestry is cited in the United Nations Convention
to Combat Desertification as a potential win-win land
use system in providing key rehabilitation and other
ecosystem services while also generating production
and income for land users.
Drylands occupy 41.3 per cent of the Earth’s surface.
When land degradation occurs in the drylands it is
referred to as desertification. The livelihoods of more
than one billion people in some 100 countries are
threatened by desertification.
There are examples from around the world where
agroforestry is being successfully practised as a form of
dryland management and soil conservation to prevent
the desertification of landscapes. Agroforestry systems
increase soil organic matter and available nutrients,
The LAMIL project enables farmers to have a steady source of income. A buyer purchases mangoes from farmers in Guinea
Image: Charlie Pye-Smith/World Agroforestry Centre