Perhaps of necessity, secondary forest, logged forest, and fragments are now being incorporated into tropical conservation planning. These areas, as well as primary forest, can be species-rich and provide habitat for many organisms. This is a practical point of view, since the tropical landscape is increasingly becoming a heterogeneous rather than a homogeneous one. Thus, many types of forests – closed or open canopy, highland or lowland, moist or dry, are being converted into a mosaic of primary forest, secondary forest and successional areas. Not all logged areas need be degraded to wasteland after timber has been removed. Furthermore, successional areas and secondary forest grow more rapidly than primary forest, and have a positive impact on carbon sequestration levels, provide habitat, and act as watersheds.
Much converted forest land is abandoned after logging or agricultural failure, or left fallow in crop rotation in swidden agriculture. This land frequently becomes reforested as so-called “secondary forest.” Such forests can grow rapidly and act as substantial carbon sinks, but these areas cause a net flux of carbon to the atmosphere due to carbon losses during logging and conversion for agriculture. Much of this land will be cut over and over.
In Brazil, large areas of converted land have reverted to secondary forest. The rates of logging and reforestation are highly dependent upon government policies (political and economic) for the Amazon region. Rondonia state is a region which is undergoing rapid forest conversion and where primary forest is being removed at a very high rate, approximately 1.5% per year. Large areas of Rondonia are covered with secondary forest (22-48%, depending on the year). Some cleared areas are abandoned and some forested areas are cleared every year. In regions such as this, (where ranchers control 70% and farmers 30% of the land), in 90 years perhaps 43-48% of the land will be in secondary forest and less than 1% in primary forest.