The Importance of Protected Lands

How effective are protected areas in saving biodiversity? Despite previous negative reports on their efficacy, a new study in PLoS Biology determines that areas such as national parks and preserves in tropical forests have helped support populations of mammals and birds over the past several years.

Researchers with the Tropical Ecology Assessment and Monitoring Network (TEAM)used more than 1,000 camera traps at 15 sites spread over three continents for the past three to eight years. They discovered that 17 percent of the animal populations they monitored increased in number while 22 percent remained constant and 22 percent decreased. The remaining 39 percent of the populations were detected too infrequently to determine a change in numbers.

The sites were located in Central and South America, Africa, and Southeast Asia—areas where high quality (or really, any) biodiversity data aren’t available. The team was able to observe 511 animal populations within the 15 sites, representing 244 species in 2.5 million pictures.

These tropical forests not only provide critical habitat to the animals and plants, they provide many invaluable ecosystem services for people—including food and fresh water, oxygen from the trees (via their metabolic process), and absorption of carbon from the atmosphere. Plus, the animals themselves contribute important services such as seed dispersal and pollination, and they help to support an intricate food web. Loss of species in forests can jeopardize the critical ecosystem services that 1.6 billion people rely upon globally.

“At a time when environmental concerns are taking center stage, these results show that protected areas play an important role in maintaining biodiversity,” says study co-author Jorge Ahumada, of the TEAM Network. “Our study reflects a more optimistic outlook about the effectiveness of protected areas. For the first time we are not relying on disparate data sources, but rather using primary data collected in a standardized way across a range of protected areas throughout the world. With this data we have created a public resource that can be used by governments or others in the conservation community to inform decisions.”

The data from the study are already being used to inform management of the protected areas that TEAM monitors. In Uganda’s Bwindi Impenetrable Forest, TEAM researchers identified a decline in the area occupied by the African golden cat, recognized as a vulnerable species by the International Union for Conservation of Nature (IUCN). Park managers noticed that these locations were heavily trafficked by eco-tourists and so redirected travelers to alternate trails. Since these management actions went into effect, there has been an increase in sightings of the cat.

TEAM hopes to extend this standardized approach to other geographic areas as a solution to measuring changes in on-the-ground biodiversity and ecosystem health outcomes.

Jaguar, Central Suriname Nature Reserve, Suriname, Image: TEAM