Pacific Southwest Research Station scientists partner with Palau to protect tropical forests

How do you protect native tropical forests in the Republic of Palau that help sustain life on Earth? Scientists from the Institute of Pacific Islands Foresty (IPIF) in Hilo, Hawai'i and communities in Palau are following nature’s lead.

In the early 2000s, Susan Cordell, research ecologist with IPIF, hiked in Palau’s tropical lowland forests, which are some of the most intact in Micronesia. But beyond the pristine forest, she witnessed highly eroded areas.

“There were these degraded savannas, or areas of shrubs and scattered trees, with what looked like red soil. But it wasn’t even really soil. Nothing could grow there,” Cordell reflects.

A history of agriculture and other land uses had cleared trees and stripped soil. Seeing the degraded areas firsthand motivated Cordell to work with state foresters on ways to help the forest recover.  She thought deeply about how to use native species to restore damaged areas.

“Across the Pacific, foresters had planted non-native acacia to restore forests. The idea was that these nitrogen fixing plants would help the soil, reduce invasive plants from cropping up, and facilitate the growth of native plants, but it never really worked out that way,” Cordell says.

Christian Giardina, then research ecologist, now director of IPIF, accompanied Cordell on her trips to Palau’s tropical forests. On one such trip, Giardina and Cordell stumbled on something unexpected—small patches of intact forest.

“We started to think this is probably from bird dispersal. They’re flying over these forests and releasing their droppings. Then, a tiny forest starts on its own and grows outward from there. We thought, why not take advantage of this?” Cordell says.

The state foresters were thrilled by the idea of planting native trees where native birds were already serving as caretakers. They coined it ‘the sweet spot project.’

Soon, the sweet spot project took off. Julian Dendy, who at the time was a graduate student from Palau and a Peace Corps volunteer, did his master’s thesis on the research project. He measured what the researchers call tree islands of different sizes—small, medium and large. Comparing these islands, he concluded that because large forests have microclimates, they would facilitate the most tree growth.

“That research helped launch a forest restoration strategy for degraded savannas in Palau. It also contributed to establishing our forest monitoring plot in the Ngardok Nature Reserve in Palau’s Melekeok State,” Amanda Uowolo, ecologist with IPIF, says.

IPIF has an over 20-year partnership with the Melekeok Conservation Network (MCN), which manages the reserve. Perched on the Island of Babeldaob, the reserve protects both tropical forest and Lake Ngardok. Ngardok is the largest freshwater lake in Micronesia, supplying residents with water, and as a wetland of international importance, is a wildlife haven. From native birds to rare orchids, life teems here.

The site’s biodiversity led to global recognition. In 2017, the Smithsonian added the four-hectare Ngardok forest monitoring plot to their ForestGEO Program. The program monitors 78 sites and 7 million trees across the world. And the Ngardok plot is the only one in the Pacific, outside of Hawai’i.

“The Smithsonian’s plot captures a moment in time, memorializing the communities’ efforts. It gives a glimpse of what it means to live a traditional life, relying on the forest for our medicine, our food and our structures,” Board Secretary Kevin Mesebeluu of Melekeok State says.

Most of the Smithsonian’s other plots are in native primary forests. But the Ngardok plot is unique in that it monitors both intact and recovering forest. That’s enabling researchers to measure how long degraded areas take to recover in real-time, filling in major data gaps.

“We’re measuring over 14,000 trees. Our research even led to a discovery of a new species. We’re also researching orchids and installed a weather station here,” Uowolo says.

IPIF and the Coral Reef Research Foundation support research of the ForestGEO monitoring plot and MCN in getting the Melekeok community out in the forest. Uowolo sees those partnerships as critical for the success of the research and as interdependent as the health of the forest is to that of the ocean.

“Our partnerships are helping connect local communities to their forest,” Uowolo emphasizes.

Men are assisting with planting native trees and women are weaving baskets to help control erosion. Community members place hand-woven coconut baskets, stuffed with husks, a byproduct of coconut oil, in erosion-prone areas. Catching sediment and trapping water, biodegradable baskets prevent sedimentation of the lake and nearshore areas.

“The community is proud, being such a small community and yet having such a big impact in terms of forestry work in the Pacific,” Secretary Mesebeluu says.

Those community efforts are sowing the seeds for the next generation of scientists. Community members from Palau are traveling to Hawai'i to learn forest restoration techniques from IPIF scientists. They’re then taking that knowledge back home with them and sharing it with others.

Secretary Mesebeluu is particularly proud of this knowledge sharing, which is starting with Palau’s youngest community members—children. Through hands-on field trips, young students are getting to see and learn about the forest monitoring plot for themselves.

“This project and our partnership with the Forest Service has really allowed the community to have more time, more space to engage with their environment and that’s such a precious thing given how we’re being developed,” Secretary Mesebeluu says.