A Grim Future for Tropical Forests

Tropical forests harbor more than half of the world's species found on land. A new study reveals that continued deforestation and logging, coupled with the effects of global warming, will devastate these precious tropical environments and the plants and animals that live there by the end of the century. 

Clear-cutting forested land destroys the environment totally, wiping out the homes and food sources for the animals that lived there. The effects of logging and climate change are more subtle, but still poignant.

Selective logging, for example, "creates a cascade of changes including elevating hunting pressure on fauna, disruption of seed dispersal, and forest desiccation that facilities fire," Gregory Asner of the Carnegie Institution wrote in a article published recently the journal Conservation Letters.

Interested in providing "a global assessment of the combined effects of current land-use and future climate change" on tropical forests, Asner pulled together satellite imagery of tropical forested areas from 2000-2005, 16 computer models of global climate, and a model that focuses on how plants specifically respond to different environmental threats.

The Amazon will be one of the hardest hit regions.

Currently, the footprint of deforestation and logging covers 29 percent of Amazonia.

If these pressures continue, the Amazon is susceptible to a 57 to 81 percent change in biodiversity by 2100. These changes include the loss of species, in tandem with the proliferation of other, more resilient species.

Similarly, the study suggests that the Congo River basin in the Democratic Republic of the Congo is also vulnerable to drastic changes in biodiversity, up to 74 percent, from continued land-use and subsequent climate change.

Forests in Asia and Oceania, though spared from extensive damage due to climate change, will suffer greatly at the expense of land use changes.

No region of the tropical forests is completely insulated from these effect, but just how much these ecosystems are altered is something we still have control over. 

Asner told Discovery News:

[This study] highlights where different types of conservation and management thinking might be applied in the future. For example, in regions where climate-driven changes in plants and other species are predicted to be large, relief from land-use changes there might provide the opportunity for species to migrate and/or adapt without the influence of other stressors.

On the other hand, in regions where land use change is currently the major driver of change and climate-driven changes are predicted to be mild, Asner added, "management decisions could be made to protect areas from further land use to allow ecosystems and species to persist."

Image: Threat to Democracy, Flickr