Thursday, November 21, 2013

New study casts doubt on effectiveness of nature preserves in Latin America

A new study indicates that protection of nature preserves may not be enough to conserve ecosystems.

Researchers studied all preserves that are larger than 500 hectares and that were designated or known before 2004. They concluded that more than 1 million hectares of reserves in 19 nations of Central and South America were degraded during a five-year period:  
In Latin America, the rate of land and forest degradation inside protected areas more than doubled from 2004 to 2009, increasing from 0.04% to 0.10% per year. This is a small fraction but of a large number. Thus, in 2004 there were 81,975 hectares of land and forest degradation inside protected areas in Latin America, while in 2009, there were 247,056 hectares—an increase of approximately 165,000 hectares. Assuming each land and forest degradation event was unique (i.e., no change, regrowth and change again during the six years) and considering only the negative changes in land cover, the 2004–2009 land and forest degradation in our protected area data set was 1,097,618 hectares—an area the size of Jamaica.
French Guiana and Guatemala experienced the most loss of natural characteristics in the studied preserves. Costa Rica, Mexico, Argentina, and Nicaragua suffered the least damage.

The researchers also examined potential causes for degradation of the region's preserves and found that only the degree of funding provided to operate them has a statistically significant relationship with the amount of damaged land. However, they also decided that the relationship is "tenuous."

Growth of a nation's gross domestic product did not have a statistically significant relationship with degradation within the preserves. That was also the case with per capita GDP and rural population growth. 

Instead, the authors posited that a variety of human economic activities accounts for the failure of the reserves to protect the  natural systems within them. "Moving away from the data and results, we hypothesize that agricultural expansion, grazing expansion, intentional burning, infrastructure development, and increased accessibility could all be causal factors driving protected area land and forest degradation in Latin America and are potential future areas of research," they wrote.

Terra-i, a remote-sensing system that monitors changes in land use, was used by the researchers to complete the study.

The paper appears in the journal Diversity.

The above graphic shows the percentage of protected land in each of the Latin American region's countries that was affected by degradation of ecosystems during the study period, 2004-2009.