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SOME PRINCIPAL AGENTS OF TROPICAL DEFORESTATION
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With fields as rocky as this one routinely being
farmed, it is apparent that many farmers
experience a lack of access to
good farmland.
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Possible Solutions
What Can Be Done?
While slash-and-burn farming is the proximate agent of much deforestation in the Selva Maya and elsewhere in the tropics, it is not accurate to view this farming activity as the
ultimate cause of deforestation. The phenomenon of a constant flood of landless immigrants into remaining forested wild lands in order to eke out an existence of subsistence farming is a symptom of broader social conditions
that very often involve skewed patterns of land ownership, poor standards of education and health care, lack of employment, and other indicators of under-development. This is a difficult problem because consideration of it
inevitably leads to discussion of politically sensitive topics such as agrarian reform--redistribution of land ownership. However, failure to realize that this very topic has been at the root of much political turmoil in
Latin America is to doom us to continue repeating the past.
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One long-term strategy possible with
secure land
tenure is planting of
valuable hardwoods such as mahogany.
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Many conservation and development workers believe that if a peasant family can acquire secure title to a piece of land, their mode of managing that land generally shifts toward activities permitting long-term sustainability,
as opposed to the cut-and-run mentality that often pervades along the tropical forest frontier. Hence, many programs aim to assist landless families in securing title to property.
In addition to providing secure land tenure, improvements in farming methods can go a long way toward decreasing the need of farmers to constantly rotate into primary forest, felling it for cropping purposes. Any technology
that aids farmers in maintaining productive, cost- and labor-effective cropping on the same acreage over extended periods of time should be an aid in saving forest. While it would surely be possible to achieve this by pouring
on expensive fertilizers, herbicides, and insecticides, this is not an advisable strategy for many reasons, perhaps chief being that farmers cannot afford such costs.
Much more appropriate is the use of "green manure" cover crops--nitrogen-fixing plants--often legumes (members of the pea family). Such plants, through the aid of nitrogen-fixing bacteria in root nodules, take
N2--diatomic nitrogen, which is not usable by plants--from the atmosphere, and "fix" it as ammonia, which is then converted by certain soil bacteria, first to nitrite and then to
nitrate, thereby enriching the soil with this important plant nutrient in a form chemically available to plants. Such green manure cover crops also add organic matter to the soil, improving soil structure and nutrient-retention
capacity.
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The seeds of change: frijol abono (Mucuna
sp.), one
of many nitrogen-fixing cover crops that enrich
soil while
helping combat weeds, allowing
sustained cultivation of the same acreage.
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Green manures often have an additional benefit beyond simply enriching the soil--that of weed suppression. As noted above, the increase in weeds under cultivation is a primary rationale for abandoning one field and moving on
to fell additional forest. Green manures can often be managed by the farmer so as to create a dense, low ground cover that aids greatly in controlling weed problems.
Our Research and Outreach
Because of the importance of shifting cultivation as a deforestation agent in the Selva Maya and elsewhere, a great deal of our research dealt with this land use. We investigated the habitats created by this style of farming,
and the ability of various faunal groups to use these habitats. We examined faunal use of the small forest patches remaining in such farming landscapes. We investigated the ability of green manure cover crops to increase
corn yields and permit sustained cultivation on the same acreage in our study area, and quantified in part the conservation gains that would be obtained if all farmers ceased cutting primary forest, through use of such cover
crops.
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Chindo Garcia, Peregrine Fund extensionist,
examines
a thriving stand of frijol abono.
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Based on all the above, we examined the desirability of different policies toward shifting cultivation. Finally, we attempted to save forest habitat in our study area by introducing farmers in a few small villages to the use
of green manure cover crops. Results of our activities
are presented under the section --"Maya Project Activities and
Results."
 Literature
Cited, Shifting Cultivation
and Hunting in Tropical Forests.
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