EPOW - Ecology Picture of the Week

Shifting Cultivation in Rainforests of Congo River Basin, Africa

Explanation:   Last week we found ourselves flying over some of the last unbroken forests of the Congo River Basin.  Beyond the forest's edge, here in western Democratic Republic of the Congo, we suddenly enter a landscape of slash-and-burn ("shifting") cultivation.  

Here, the primary swamp forests have been cut, the main timber trees extracted, and the rest burned, leaving a thin, nutrient-poor tropical soil to hold no more than 4-5 years of crops ... mostly manioc, maize, and banana, starches all.  Much of the primary forests and large-bodied wildlife -- the carnivores and ungulates -- have been eradicated for bushmeat trade or to eliminate dangerous encounters, such as with crocodiles and leopards.  

People of the region have little choice but to continue the patterns of deforestation.  It is not the cutting, nor the burning, nor the agriculture that is of conservation concern.  Rather, it is the extent of these practices across the land, to feed and house a burgeoning human population.  
 

Note the different ages of slash-and-burn patches, the oldest
in the upper left being probably no more than 10 years old.
An edge of primary forest occurs in the bottom right; such
forests could serve as no-hunting refuges so 
wildlife populations have a chance to maintain themselves. 

 
The answer must address as much the need for reforming dietary habits and social  structures, and attending to problems of governmental stability and conservation of cultural traditions, and providing medical and basic resource needs for the people of the region, as it does the need to conserve primary forests for wildlife, water, fish, and other renewable natural resources.  Only from such a holistic approach can a long-lasting solution be found.  

Most villages of the region are laid out linearly along old
footpaths or defunct roads.  This is quite a different settlement pattern
than villages found in other tropical forests of the world.

  
Shifting cultivation will not go away.  Instead, one approach to a 
compromise for conservation of forest ecosystems is to establish
guidelines for conserving elements of older forests within and among
the cultivation plots.  For example, shown here are (1) remnant
large snags and live trees retained within the plantation plots, which 
provide habitat for some animals; (2) curtains of remnant trees, such
as in the upper left of this photo, between plots; (3) a range
of successional stages or plot ages, which provide a diversity of 
vegetation and habitat conditions; and (4) retention of both small 
and large patches of primary forest cover.  Each of these measures
has a positive long-term benefit to helping maintain soil and ecosystem
health and future generations of agricultural crops.