Go read up on Slash and Burn and forest fires. When I tell you to READ I really mean READ. Not "Reply with some stupid remark as soon as possible"
YOU READ-
http://en.wikipedia.org/wiki/Slash-and-burn
Although a solution for
overpopulated tropical countries where
subsistence agriculture may be the traditional method of sustaining many families, the consequences of slash-and-burn techniques for
ecosystems are almost always destructive.[SUP][
citation needed][/SUP] This happens particularly as population densities increase, and as a result farming becomes more intensively practiced. This is because as demand for more land increases, the fallow period by necessity declines.
The principal vulnerability is the nutrient-poor soil, pervasive in most
tropical forests. When biomass is extracted even for one harvest of wood or charcoal, the residual soil value is heavily diminished for further growth of any type of vegetation. Sometimes there are several cycles of slash-and-burn within a few years time span; for example in eastern Madagascar the following scenario occurs commonly. The first wave might be cutting of all trees for wood use. A few years later, saplings are harvested to make charcoal, and within the next year the plot is burned to create a quick flush of nutrients for grass to feed the family
zebu cattle. If adjacent plots are treated in a similar fashion, large-scale
erosion will usually ensue, since there are no roots or temporary water storage in nearby canopies to arrest the
surface runoff. Thus, any small remaining amounts of nutrients are washed away. The area is an example of
desertification, and
no further growth of any type may arise for generations.
The ecological ramifications of the above scenario are further magnified, because
tropical forests are
habitats for extremely
biologically diverse ecosystems, typically containing large numbers of
endemic and
endangered species. Therefore, the role of slash-and-burn is significant in the current
Holocene extinction.
Slash-and-char is an alternative that alleviates some of the negative ecological implications of traditional slash-and-burn techniques.