Protecting Ecosystems and Alleviating Poverty with Parks and Reserves: 'Win-Win' or Tradeoffs?

National parks and reserves are globally popular approaches to protecting biodiversity and the supply of ecosystem services. Because these protected areas limit agricultural development and exploitation of natural resources, they are frequently opposed in developing nations where reducing poverty is an important social objective. Conservation advocates argue that protected areas can alleviate poverty by supplying ecosystem services, promoting tourism and improving infrastructure. Thus 'win-win' scenarios may be possible in which ecosystems and their services are protected and poverty is alleviated. Previous studies (Andam et al. in Proc Natl Acad Sci USA 105(42):16089-16094 2008; 2010) suggest that Costa Rica's protected area system reduced deforestation and alleviated poverty. We demonstrate that these environmental and social impacts were spatially heterogeneous. Importantly, the characteristics associated with the most avoided deforestation are the characteristics associated with the least poverty alleviation. In other words, the same characteristics that limited the conservation effectiveness of protected areas may have improved the social welfare impacts of these areas. These results suggest that 'win-win' efforts to protect ecosystems and alleviate poverty may be possible when policymakers are satisfied with low levels of each outcome, but tradeoffs exist when more of either outcome is desired.