Do protected areas halt deforestation? The case of Jamaica...

View of Blue Mountains, Jamaica. Image credit, Wolmadrian.Whenever I hear the news that a reserve or park has been created to protect some area of ecological importance, I breathe a sigh of relief. A threatened rainforest or coral reef will now survive to see the light of day.

But do protected areas really work in preventing habitat loss? A new study on forest clearance in a large national park in Jamaica casts some doubt. Researchers used satellite imagery to measure deforestation over a 19-year period (1983-2002) in a section of the 196,775 acre Blue and John Crow Mountains National Park (BJCMNP).

The study published in the journal Biological Conservation found that forest clearance continued at similarly high level after the creation of the protected area (1992-2002) as before (1983-1992). Coffee and cash crop farming were almost exclusively responsible for the loss. Total forest cover declined from 80.2% to 70.5% during the study period. Meanwhile forest fragmentation increased - existing forest patches decreased in size while the number of patches and the spaces between them increased.

On the positive side, regeneration of previously cleared forest increased leading to a decline in the net deforestation rate (i.e. forest clearance - forest regeneration).

Is past research on the effectiveness of protected areas flawed?
The researchers raise some red flags about past studies, which have found that protected areas can be effective in halting forest clearance. Past studies have largely reached those conclusions by finding that deforestation rates in parks are lower than adjacent unprotected areas. But this may not be an apples-to-apples comparison. For example, montane protected areas are often at higher elevation and inherently less accessible than adjacent unprotected forest.

The new study avoids this methodological bias by comparing deforestation rates on the same land before and after designation as a protected area. According to the authors, only three other studies have taken this approach and they all found that ecological degradation remained constant or increased after the designation of a protected area. 

However this study runs into a methodological problem of its own - it may be that social or economic conditions had changed in the period of 1992-2002 and deforestation would have been even worse if the Blue and John Crow Mountains had not been declared a protected area.

Implications for conservation...
Nevertheless, this study, and the others like it, have important global implications for conservation work. The world spends $5.5 billion on protected areas every year. If protected areas are not effective tools in some situations we absolutely need to know so we can figure out how to make them work or put our limited resources into better solutions.

This research is especially important for conservation of tropical montane forests in the Caribbean, a global hotspot for biodiversity. The BJCMNP contains 30% of Jamaica's remaining forest cover and houses a very high number of endemic species such as the Homerus swallowtail, Papilio homerus, the largest butterfly in the Western Hemisphere. It also provides important environmental services by providing the water supply for over 40% of the country and protecting lowland areas from flooding.

Neither Jamaica, nor the world can afford to entrust the future of threatened ecosystems in faith alone.

 
--Reviewed by Rob Goldstein

Chai, S., Tanner, E., & McLaren, K. (2009). High rates of forest clearance and fragmentation pre- and post-National Park establishment: The case of a Jamaican montane rainforest Biological Conservation, 142 (11), 2484-2492 DOI: 10.1016/j.biocon.2009.05.020