Decades later, ʻōhiʻa repopulation results encouraging

by the University of Hawai’i
April 29, 2022

The ʻōhiʻa (metrosideros polymorpha) tree, which is endemic to Hawaiʻi, may be easier to repopulate than previously thought. New University of Hawaiʻi at Mānoa research provides encouragement and guidance to those wanting to reestablish ʻōhiʻa populations in areas that have suffered significant mortality due to the recent spread of the fungal pathogen known as rapid ʻōhiʻa death.

The study is the culmination of nearly 40 years of research on Hawaiʻi Island, spearheaded by School of Life Sciences Emeritus Professor Dieter Mueller-Dombois. The research focuses on portions of an intact, mature native lowland rainforest located in the Puna District, which were deforested in the mid-1980s.

Researchers compared the aboveground carbon accumulation of trees that were replanted in the deforested area (secondary succession) as compared to trees that were planted to new land created by lava nearby (primary succession). Higher aboveground carbon accumulation is one indicator of healthy trees.

Results countered previous research that ʻōhiʻa is a slow-growing species. In addition, ʻōhiʻa planted in second-growth forests were characterized as highly productive and resilient to disturbance. Results indicated that mature ʻōhiʻa trees planted through primary succession provided a high level of aboveground carbon accumulation, while ʻōhiʻa trees planted through secondary succession showed approximately half of the carbon accumulation than from primary succession.

Researchers also discovered that ʻōhiʻa trees were able to be reproduced quickly, as long as factors such as non-native plant invasion did not disrupt their development through competition.

Keep reading: https://www.hawaii.edu/news/2022/04/29/ohia-repopulation-results-encouraging/

Read the Ecological Applications paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2539