SSRI News Fall 2007 > News Feature

News Feature

Highlighting Dr. Tom Giambelluca

In this issue of the newsletter, we are pleased to feature one of the College's most prolific researchers, Dr. Tom Giambelluca, Department of Geography, who has been actively studying global warming for the past 20 years - even before Al Gore's time. His research looks at how global warming will impact native ecosystems and water resources. With M.A. student Mark Alapaki Luke, Giambelluca has found evidence that Hawai'i's climate has already warmed significantly, especially at high elevations.


Dr. Giambelluca first came to UH Mānoa as a PhD student after receiving his M.A. at the University of Miami. After completing his doctorate at UH, he joined the faculty of the Geography Department in 1986.


Dr. Giambelluca's group has been operating a network of microclimate stations on Haleakalā since 1988. This system, known as HaleNet, is a valuable resource for studying climate-vegetation interactions, alien plant and animal invasions, and local climate shifts associated with global warming. Data from this network have served as the basis for numerous papers and theses. HaleNet has facilitated an intensive study of the treeline area, above which either low temperature or insufficient moisture limits tree survival. Giambelluca, together with PhD student Guangxia Cao, found evidence for a possible shift toward a drier climate over the past 25 years.


In local water resources circles, Dr. Giambelluca is best known for his research on groundwater recharge and patterns of mean and extreme rainfall. His dissertation research is still widely used in water resource planning in Hawai'i, and his "Rainfall Atlas of Hawai'i" is still frequently cited, despite being published more than 20 years ago. More recently, he has directed his attention to a variety of interests under the broad topic of land-atmosphere interaction. For the past 15 years, he has been actively studying the effects of tropical deforestation on regional climate and hydrology. This work has taken him to two of the world's deforestation "hot spots", the Amazon basin and SE Asia. He and his students, and his technical assistant, Michael Nullet, have been highly productive, publishing dozens of papers on these topics, and successful in garnering extramural sponsorship to support the work.


Giambelluca has been studying Hawai'i's tropical montane cloud forests in recent years. These zones are extremely valuable as areas of high water input and as the last refuge of many of Hawai'i's threatened and endangered native plants and animals.


Additionally, in the past four years, Dr. Giambelluca's group has been studying how alien tree invasion in Hawai'i affects water processes and carbon exchanges. With funding from NSF and the US Geological Survey, they set up state-of-the-art monitoring sites at Nahiku and Ola'a in Hawai'i Volcanoes National Park on the Big Island, which provide the first documented evidence of the negative effects of alien tree invasion on Hawai'i's water resources.


Dr. Giambelluca's work has not been restricted to Hawaii. During the past seven years, Dr. Giambelluca has continued to conduct field research in SE Asia and Brazil. Preliminary results from their current SE Asia research point to possible major impacts of the rapid expansion of rubber tree cultivation in the region on water and carbon dynamics. In the savanna region of central Brazil, Dr. Giambelluca has worked with a team of ecologists to study how deeply-rooted woody plants in the cerrado change ecosystem and water dynamics by redistributing water within the soil.


One of his most interesting studies was funded by two consecutive NSF grants. They conducted intensive field studies on the impacts of unpaved roads in the mountains of northern Thailand. This region is sparsely populated by farmers from ethnic minority groups who have been routinely blamed for downstream sedimentation and other water quality problems. Dr. Giambelluca and collaborators, especially Dr. Alan Ziegler, were able to demonstrate that the expansion of roads in the region is a primary cause of accelerated soil erosion and is at least as culpable as upland farming as a source of sediment in streams.


Without question, Dr. Giambelluca has made significant contributions to our understanding of climate change and global warming. He has also been a staunch supporter and mentor to students, and is a valued member of his department and college for his service contributions.



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