BOGOR, Indonesia—If you are a land-use planner in a tropical country, how do you decide whether an area should be used to grow food, conserved for its biological diversity or protected for its ecosystem services (such as erosion control or pollination)?
Conventional yardsticks for measuring the value of ecosystem services miss the nuances of highly varied tropical landscapes, researchers say.
They especially underestimate the economic value of places with high biodiversity; these sites are often far from populated areas, according to a new study in the journal Biological Conservation.
As a result, policies designed to protect areas where ecosystem services have high economic value may exclude places high in biodiversity, even though they are crucial for food security and livelihoods in remote communities, the study’s authors say.
“We need to take a more nuanced approach and concentrate our limited resources on areas that not only provide ecosystem services, but are also correlated with high biodiversity,” said Terry Sunderland, a senior scientist with the Center for International Forestry Research (CIFOR) and one of the study’s authors.
ECONOMIC VALUE CENTERS AROUND PEOPLE
With growing demand for food production in tropical countries, planners use the value of ecosystem services to make land-use decisions. But most calculations are based on average values that do not reflect the great variation in tropical ecosystems, the study says.
Using data from TEEB (The Economics of Biodiversity and Ecosystems), which they call “arguably the most comprehensive ecosystem services value database,” the authors mapped and analyzed the economic value of ecosystem services in tropical areas of Latin America, Asia and Africa.
Despite the common assumption that protecting areas that provide high-value ecosystem services also protects places with high biodiversity, the researchers found that those locations often did not overlap.
Economic value tends to be highest where a large number of people benefit from a service, says Roman Carrasco of the National University of Singapore, one of the study’s authors. But the places with the greatest biodiversity are usually remote forests far from population centers.
“Higher biodiversity occurs in relatively undisturbed or pristine forest—that’s where the highest number of species resides,” Carrasco said. “If you have a lot of consumers of a service like water regulation, you will have higher value, but species richness will be lower.”
To compensate, planners should include factors that “go beyond dollar value,” Carrasco said. “If we focus our policies on economic concerns, we are going to miss out on biodiversity. That goes against conventional wisdom,” which assumes that ecosystems are more homogeneous, he said.
Biodiverse forests are extremely valuable to people living in or near them who depend on timber, fruits, fiber, water regulation and other services they provide.
Even though fewer people benefit from those services, because the population is sparser in more remote areas, their reliance on forests for cultural benefits and food could be higher than that of people in urban areas—a nuance that broad-based calculations fail to capture, Sunderland and Carrasco say.
“The role of forest products as an economic safety net including benefits for dietary diversity, child nutrition and health for millions of people living in the tropics is evident,” they write in the study.
Income from forests and forest products provides more than one-fourth of rural family income, almost as much as crops, according to the CIFOR-led Poverty and Environment Network.
The new study indicates that planners must add biological diversity into their accounting, especially when comparing the benefits of agriculture to those of forests, but there is no agreement on how to place a dollar value on biodiversity, Carrasco says.
“We need to try to quantify human well-being, not just economic values,” he said. “It’s not that we have to stop using economic value—it’s that we have to complement it with other indicators.”
That means trading general maps of ecosystem services for more detailed studies of the importance—and therefore the value—of services for local people, even in more isolated places.
An Amazonian forest is far more valuable to an indigenous community living in it than to a person in a distant city who has other types of income, he says.
“We need to look at how fundamental the services are,” Carrasco said. “If you cannot survive without the forest, that means the forest has an infinite value for you.”
For more information about the topics of this research, please contact Terry Sunderland at firstname.lastname@example.org.
This research was supported in part by USAID and forms part of the CGIAR Research Program on Forests, Trees and Agroforestry.