Climate change research at UH Hilo: Collecting data on forests and trees

UH Hilo researchers believe the biggest challenge that Hawaiian tree species will face in the future is how quickly they will get water, especially in higher temperatures.

By Anne Rivera.
This story is the second in a series on climate change research at UH Hilo.

Joanna Norton and Prof. of Biology Becky Ostertag stand together in a garden.
(l-r) UH Hilo graduate student Joanna Norton and Prof. of Biology Becky Ostertag. Photo by Zoe Coffman.

Scientists at the University of Hawai‘i at Hilo are tackling climate change issues with numerous research projects focusing on a variety of target areas ranging from testable theories to the collection of data. In many of the projects UH Hilo faculty, graduate students, and island resource managers are working together to conduct important collaborative research focused on building the community’s ability to adapt to future climate and land use changes.

Professor of Biology Becky Ostertag leads two such projects—a long-term forest research project with many partners across the Hawaiian islands, and a separate research study with graduate student Joanna Norton. Both projects link established and potential problems related to our forests to further help scientists and island resource managers understand the effects of climate change on the island’s environment.

Forest studies

Ostertag’s project, called the Hawai‘i Permanent Plot Network or HIPPNET, is the deployment of permanent research sites across Hawai‘i that track various factors in Hawaiian forests—the birth and death of trees, growth rates, species and so forth—all monitored with the data compiled together like an information packet. This comprehensive history helps to evaluate how Hawaiian species respond to climate fluctuations and allows researchers to make predictions about how Hawaiian forests will do with long term climate change. The collected field data relates to climate change by linking factors such as minimum and maximum temperatures, rainfall, solar radiation, soil moisture and wind speed.

The biggest issue that Hawaiian species will face is how quickly they will get water, especially in higher temperatures, Ostertag explains.

“Water is going to become an important issue with climate change,” she says.

Prof. Ostertag earned her bachelor of arts in biology from Carleton College in Northfield, MN, and later received her doctor of philosophy in botany from the University of Florida in Gainesville. At UH Hilo, she teaches, leads her own research projects, and chairs and advises students in the Tropical Conservation Biology and Environmental Science graduate program as she is with Joanna Norton.

Ostertag’s HIPPNET project is a collaboration with the Institute of Pacific Island Forestry of the USDA Forest Service, the University of California-Los Angeles, and UH Mānoa, and has received funding from the National Science Foundation, the Pacific Southwest Research Station of the USDA Forest Service, and the Pacific Islands Climate Science Center based at UH Hilo.

Logos of the various agencies supporting the HIPPNET project.
The HIPPNET project is a collaborative research project with support from a cross section of agencies. Click to enlarge.

Additional funding from the Pacific Islands Climate Science Center allows Ostertag and fellow researchers to investigate sapflow, the rate in which trees take up water.

Albizia studies

Norton’s research is part of the UH Hilo collaborations with the Pacific Islands Climate Science Center that link graduate students, agency and community natural resource managers and faculty to focus on today’s challenges related to climate change.

Norton’s project focuses primarily on alternative agricultural methods investigating the use of an invasive albizia tree species (Falcataria moluccana), found here on Hawai‘i Island, as an alternative fertilizer.

Agriculture is one of the biggest influences in climate change—carbon dioxide and methane gas are contributors, however nitrous oxide is the biggest component.

“It is a much more powerful greenhouse gas and it’s coming out of agricultural fields which makes it reactive,” Norton explains.

Oftentimes agricultural gas emitted from the fertilizers is not mentally registered because it is considered routine and regular agriculture.

Norton’s research project includes the collection of albizia trees which are chipped, composted and then spread across agricultural lands ranging from Hilo to Kohala. After the composted albizia trees are dispersed across these agricultural plots, Norton will compare it to chemical fertilizers by analyzing differences in plant growth, soil and plant nutrient levels, and soil water holding capability.

A large pile of wood chips and an orange tree trimming truck in a horse pasture, a black and white horse looks on.
UH Hilo graduate student Joanne Norton’s research project includes the collection of albizia trees, which are chipped, composted and then spread across agricultural lands ranging from Hilo to Kohala. Photo by J. Norton.

Norton originally hails from Washington, DC, but has spent half her life in Hawai‘i. She earned a bachelor of science in biology from UH Hilo, and is now earning a master of science at the university’s Tropical Conservation Biology and Environmental Science program.

She says she came back to school after being in the “work world” and continues to work with various employers conducting agricultural experiments. Her research project is similar to her work, however, she is given the freedom to design the agricultural question.

“Here at UH Hilo, I am learning the latest research on agriculture, invasive species, and climate change, which gives my work context,” she says. “I’m learning how to ask and answer questions in a scientific way as well as learning the logistics and planning that goes into a research project.”

By designing and implementing her own research project, Norton is gaining more than just answers to untested questions—she is learning useful and applicable techniques and information that will help her understand climate change and how adjustments might be made to adjust or prevent these fluctuations.

Partnerships and collaborations

Norton’s agricultural investigations also interfaces with the HIPPNET forest research project, which is in collaboration with a worldwide network called the Center for Tropical Forest Science—projects involved with this network use similar tools for data analysis, which allows for cross-site studies. These cross-site studies show how Hawaiian forests compare to other tropical forests and some temperate forests across the globe.

A map of the world showing the countries participating in The Center for Tropical Forest Science global network.
The UH Hilo HIPPNET project is part of The Center for Tropical Forest Science – Forest Global Earth Observatory (CTFS-ForestGEO), a global network of forest research plots and scientists dedicated to the study of tropical and temperate forest function and diversity. The multi-institutional network comprises over 60 forest research plots across the Americas, Africa, Asia, and Europe, with a strong focus on tropical regions. CTFS-ForestGEO monitors the growth and survival of approximately 6 million trees and 10,000 species. Click photo to enlarge. Source.

This ability to compare Hawaiian forests and species with the outside world influences Norton’s project. Norton’s project compares a variety of factors, one of which includes the albizia tree fertilizer’s ability to retain water. The HIPPNET plot project’s observations and data analyses show that the water intake rate of Hawaiian tree species means there is a need for alternative fertilizer options. Norton is researching and testing one of many purposed alternative methods.

Norton’s work is funded by the Pacific Islands Climate Science Center, which works in conjunction with managers and scientists from a collaborative agency called the Big Island Invasive Species Committee. Norton’s partnership with BIISC—part of the Manager Climate Corps—is to ensure that her research is applicable to the community—invasive species have become a hard-pressing problem on the island because the invaders force competition between native and invasive species for limited resources and nutrients.

Norton looks forward to continuing her work in agricultural research after graduation. She wants to combine her “on-the-ground skills with the expertise and scientific perspective.”

“Whether my work is primarily in agriculture, land conservation, or climate science, I hope to use my positions to take a multidisciplinary systems approach that is concerned with the entire situation,” she says.

This post was updated on 3/16/2017 to include more details about community partnerships and research projects.


About the author of this story: Anne Rivera (junior, communication) is a public information intern in the Office of the Chancellor.

-UH Hilo Stories


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