Today's necessity costing tomorrow's promise
In traditional Madagascan culture, slash-and-burn agriculture, or tavy, is a way by which young people can gain new lands. Areas not being used are allocated, cleared and then burnt to make way for croplands.
Short Term Gain...
As the forest is burnt, the nutrients contained within the trees and plants is released into the soil. Unfortunately, once the protective cover of the canopy is gone, the soil is vulnerable to erosion. As a result, much of the soil is lost, and it's only possible to get one or two year's worth of harvest before the land is abandoned.
...For Long Term Loss
Soon the land is left fallow, and it will take decades to recover. In the meantime however, this land cannot provide any benefits to either local communities or the species that need it, this in turn contributes towards habitat fragmentation.