Congress Throws Tropical Forest Research Program a Lifeline
Climate researchers and ecologists laud the continuation of effort to fuse data from tropical forests with modeling.
Maria Uriarte, a forest ecologist at Columbia University, records damage that September 2017's Hurricane Maria did to trees in the Toro Negro state forest in Puerto Rico. Uriarte and collaborators funded by NGEE-Tropics are using the data to improve how climate models represent the damage that hurricanes cause to tropical forests. Credit: Kevin Krajick, Columbia University
By Gabriel Popkin
More than a year after Department of Energy (DOE) officials told researchers that a major tropical forest research program would shut down, Congress has ordered the department to reverse course and keep it going.
The Next-Generation Ecosystem Experiments–Tropics, or NGEE-Tropics, launched in 2015 as a 10-year, $100-million effort to better coordinate observations and experiments in tropical forests with computer models that simulate those forests. But in 2017, the Trump administration proposed a budget that would have zeroed out NGEE-Tropics and sharply cut funding for the DOE division housing the project.
“All of a sudden we got this instruction to pull up the landing gear and keep flying.”
On the basis of this budget proposal, DOE officials told project scientists to wind down their work by 30 September 2018. However, the fiscal year (FY) 2019 budget that Congress passed last month for the DOE’s Office of Science includes funding for NGEE-Tropics.
“The landing gear was out—we were ready to land the project,” said Stuart Davies, a forest researcher at the Smithsonian Tropical Research Institute based in Washington, D. C., and NGEE-Tropics’ chief scientist. “Then all of a sudden we got this instruction to pull up the landing gear and keep flying.”
A Productive Partnership
“NGEE-Tropics was designed to solve a problem: Computer models meant to predict the future of Earth’s climate and ecosystems struggle to represent ecological processes in tropical forests.”
NGEE-Tropics was designed to solve a problem: Computer models meant to predict the future of Earth’s climate and ecosystems struggle to represent ecological processes in tropical forests, which play a critical role in determining the global climate. Project-funded scientists designed observation campaigns and experiments to feed directly into computer models, a synergy that researchers say had previously been lacking.
For Davies, who oversees a network of 67 forest research plots in 27 countries, collaborating directly with modelers has been “very productive.” He learned, for example, that models often incorrectly estimate tree mortality rates. Because dead trees decay and release carbon dioxide, correctly modeling their death rates is key to predicting how much carbon forests will store or emit. Davies and his collaborators designed studies to better determine what factors cause trees to die.
Modelers involved in the project have likewise learned from field scientists such as Davies. For example, Davies found that modelers were concerned about how to represent tree seeds in tropical forest soils because many temperate forest trees grow from seeds stored for a long period in soils. Through discussions with field scientists, modelers learned that tropical forest soils store few seeds, knowledge that allowed modelers to better simulate tree germination and growth, Davies explained.
The project has generated more than 80 research publications, according to its website. It has also enabled researchers to spend time synthesizing results from many individual studies, noted Maria Uriarte, an ecologist at Columbia University in New York who is on the project’s advisory board. “It’s very hard for any one research group to take that on,” she said.
In spring 2017, NGEE-Tropics leaders learned that the project would not continue and began winding down their work or seeking other funding sources.
In spring 2018, however, the Senate Appropriations Committee’s Energy and Water Development Subcommittee proposed funding NGEE-Tropics at “not less than” $5.8 million dollars in fiscal year 2019, which begins on 1 October. Both the Senate and House subsequently passed legislation including that language, and President Trump signed the bill on 21 September in Las Vegas.
“The scope of the project only warranted funding within the $5–8M range each year since its start.”
Although it’s unclear who authored the funding language, both the subcommittee’s chair, Lamar Alexander (R-Tenn.), and ranking member, Dianne Feinstein (D-Calif.), have major DOE labs in their states: Oak Ridge National Laboratory and Lawrence Berkeley National Laboratory, respectively. NGEE-Tropics is led out of Berkeley Lab, with Oak Ridge researchers providing support.
Neither senator’s staff responded to questions about why the subcommittee funded the program. DOE program officers and scientists also declined requests for interviews. But Gary Geernaert, director of the department’s Climate and Environmental Sciences Division, confirmed in an email that the department will follow Congress’s directions and that the new figure doesn’t represent a cut compared to what the department spent in previous years.
“Unlike our earlier expectations that funding for this project could ramp up to $10M during the course of the research, the scope of the project only warranted funding within the $5–8M range each year since its start,” Geernaert wrote.
Maria Uriarte and collaborators funded by NGEE-Tropics are combining airborne measurements of tropical forests with field data to improve climate models. The data on her screen were collected remotely from airplanes over Puerto Rico’s El Yunque National Forest. Credit: Kevin Krajick, Columbia University
For example, NGEE-Tropics provided funding for a NASA airplane to fly over Puerto Rico in March 2017 and take data using lidar, a laser-based technology that is considered the gold standard for remotely measuring forest biomass and structure. After Hurricane Maria leveled many of the island’s forests in September 2017, DOE and other agencies teamed up to fund a second lidar flight. The before-and-after snapshots provide unprecedented data on how tropical forest biomass and structure respond to major disturbances, which are likely to increase in the future, Uriarte said. The resulting insights will also inform the NGEE-Tropics modeling effort.
Abigail Swann, an ecoclimatologist at the University of Washington in Seattle who is not part of the NGEE-Tropics team, is excited about the project’s Functionally Assembled Terrestrial Ecosystem Simulator (FATES). The simulator incorporates ecological processes informed by data from field studies such as Davies’s and Uriarte’s.
Previous models have estimated many of these processes in crude or inaccurate ways, limiting their predictions’ accuracy, Swann said. But FATES could change that. She said her team has already begun using FATES to study how forests affect climate. “I’ve been calling my group user zero,” she said.
Hearing that the program would continue “was a great relief,” Davies said. “One or two or three years of data is only going to scratch the surface” of understanding processes such as how flooding or drought affects tree death, he said.
The stop and start delayed his research somewhat, he admits. But, he added, “I’d be complaining much more if we didn’t get the green light.”