New Group

John Skillman jbs11 at psu.edu
Fri Jan 31 00:57:25 EST 1997


Agroforestry, as considered by the ICRAF (International Council for 
Research in Agroforestry) is a part of the agriculture-forestry 
continuum with interfaces between annual crops, trees, and often 
livestock.  This is one approach towards both sustainable agriculture 
and sustainable forestry.  Agroforestry is recognized as a high priority 
for agricultural research in tropical regions (ICRAF, 1988).
The model agroforestry system which many people are familiar with is 
"traditional" coffee cultivation where the coffee shrubs are grown under 
trees.  The trees may be monospecific or may a mixture.  One outcome of 
research on this model system is that the greater the mixture of tree 
species grown in this managed system the more structurally complex it is 
and consequently the greater the number of non-plant species that can be 
found there.  There is evidence that these traditional coffee 
plantations serve as a biodiversity refuge (a place where the forest 
critters can escape to) as tropical forests are cleared.  An example of 
this with direct implications for North Americans is that many northern 
songbirds that migrate to the neotropics during the winter are thought 
to be declining partly as a result of changes taking place in how coffee 
is grown.  More and more coffee is grown in monoculture plantations (no 
trees) requiring greater inputs of fertilizer (fast growing sun plants 
require more nutrients then slow growing shade plants) and pesticides 
(forested coffee plantations presumably support greater numbers of birds 
and beneficial insects that keep the insect pests in check).  The 
scenario looks like this; (1) Tropical deforestation coupled with loss 
of "substitute" forest in the form of agroforested fields results in 
loss of habitat for migratory birds.  (2) Loss of migratory birds in 
North America leads to more outbreaks of insect pests increasing crop 
losses and insect mediated disease.  Of course the loss of the tree 
production in what had been a tropical agroforested field has many 
social and economic implications for the farmer/forester too.

So yes, agroforestry is quite distinct from forestry as conventionally 
practiced in the US and Europe.  It is not about growing trees like a 
field crop but rather growing trees with field crops.  Consequently I 
suggest that individuals that are interested in forestry issues 
establish their own foretry newsgroup.





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