Source: Lance Nixon, South Dakota State University

NASA is paying researchers on the cool prairies of South Dakota to help track biodiversity in the steamy rain forests of the Brazilian Amazon.

It’s not as odd as it sounds.

Professor Mark Cochrane in South Dakota State University’s Geographic Information Science Center of Excellence said much of the work relies on interpreting satellite imagery, one of the strengths of the SDSU center. Cochrane and his colleagues at SDSU and other institutions are mapping three specific kinds of forest disturbances in the Amazon: fragmentation of the forest into smaller parcels, logging, and fires.

In addition, Cochrane has two SDSU doctoral students on the ground in Brazil doing survey work to determine how certain indicator taxa, or groups of organisms, are affected in those disturbed forest areas compared to undisturbed areas.

The National Aeronautics and Space Administration is funding the three-year project with a grant of about $1.1 million, of which $83,104 is a subcontract to Hobart and Smith Colleges. The SDSU component of the study is just over $1 million.

“Basically what we’re looking at is the biodiversity effects of human land use in the Brazilian Amazon,” Cochrane said. “Typically when we’ve looked at the Amazon for, say, the last three decades, we’ve all heard about slash/burn deforestation. And yes, there has been a lot of deforestation in the Amazon. About 17 percent of it has been cleared. But what people don’t appreciate is that an equal amount of forest, or potentially even more, has been impacted in other ways.”

Brazil is taking important steps to protect its rain forests, Cochrane said, but the task of simply mapping forest disturbance is enormous.

The international study involves not only SDSU, but also researchers in Brazil and at other universities in the United States and the United Kingdom. Working together, scientists will analyze more than 2,000 satellite images from two different satellite systems — Landsat and MODIS — to map different types of forest disturbance.

To do that, the researchers will rely in part on methods they’ve developed themselves. For example, fires in the Amazon rain forest — many of which are set by man to clear forest or maintain clearings — are anything but spectacular. Since a single pixel of a Landsat satellite image carries information about a land area that is 30 meters to a side, it requires careful analysis of those images to detect such damage, Cochrane said.

“A four-inch fire going through a rain forest, what are you going to see? You’re not going to detect the fire, but we can detect the damage from it. The canopy gets thinned tremendously. What we can see, if we look from space, is more of the forest floor. The forest floor is brown. The canopy is green. I can look at the percentage change in how much brown there is in that signal. In the end what I can do is actually map the areas in which deforestation or damage has occurred.”

That mapping gives SDSU doctoral students Raphael Andrade and Luiz Mestre coordinates to investigate on the ground in Brazil as they catalog biodiversity in damaged areas so that they can compare it to undisturbed forest.

“The whole point is, what do these disturbances cause in terms of a response from biodiversity? What we do is we go out into these areas where we have different disturbance types, and areas that aren’t disturbed,” Cochrane said. “Specifically what we’re looking at are birds, trees, ants, and dung beetles. What we try to look for are what we call ‘indicator taxa.’ These four groups basically tell us pretty well what the entire forest is doing.”

The study will provide a better understanding of how long it takes the rain forest to rebound from disturbances.

Cochrane’s SDSU colleague, professor David Roy, and his doctoral student, Sanath Kumar Sathyachandran, are providing analysis of the MODIS satellite images to determine which active fires are detected.

The initial analysis of Landsat imagery is done by colleagues in Brazil, where collaborators on the project include Carlos Souza Jr., director of Imazon, the Amazon Institute of People and the Environment. Other collaborators in Brazil include the Federal University of Lavras and the Emilio Goeldi Museum.

Jos Barlow of Lancaster University in the United Kingdom also collaborates in tracking the biodiversity impacts of fire disturbance. Assistant professor Eugenio Arima of Hobart and William Smith Colleges is contributing research about socioeconomic forces that play a role in forest disturbance.

At SDSU, Cochrane and post-doctoral research associate Izaya Numata will integrate all of the data from the project’s various components to determine the effects of forest disturbance on biodiversity for the entire Brazilian Amazon. In addition, SDSU graduate student Christopher Barber, who holds a NASA Fellowship, will use these findings to assess the performance of all protected areas (parks, national forests, indigenous lands) across the Amazon.

Cochrane said deforestation and forest disturbances in the Amazon basin are issues that affect people around the world. Climate on other continents responds to changes in the Amazon in ways that scientists are only beginning to understand. In addition, threats to biodiversity mean that plants with potential pharmaceutical uses could become rare or extinct. And clearing of forest results in more Brazilian farmland, which in turn affects world markets for crops such as soybeans.

+ Read original SDSU press release [external link]