Koa trees often have low forks and inherently poor stem form, which may limit the potential economic and cultural returns from koa forestry. Gap silvicultural techniques may be used to help maintain apical dominance and thereby improve stem form, allowing the possibility to sustainably manage for high value koa (e.g., canoe logs).
For his Master’s thesis research at the University of Hawai‘i at Mānoa, Achyut Raj Adhikari is studying two fungal diseases of Acacia koa.
Dr. Anna Sugiyama studied intraspecific variation of Acacia koa as part of her post-doctoral research. Specifically, she tested for (1) intraspecific tradeoffs in functional traits, (2) local adaptation and phenotypic plasticity, (3) whether adult traits can predict seedling performance.
There is a growing interdisciplinary movement to integrate place-based knowledge and local practices into resource management in Hawaiʻi through community-based approaches. This research explores the underlying conditions for successful implementation of community-managed forests (CMF) in Hawaiʻi, with a focus on how specific land ownership arrangements and assemblage of actors influence the collaborative resource management process and outcomes.
A limiting factor for native species restoration at high elevation sites in Hawai‘i is exposure of planted seedlings to winter frost. Frost damage reduces survival until seedlings grow tall enough to escape the frost zone concentrated at the soil surface. Artificial frost protection devices, consisting of a single layer of vertically oriented shade cloth placed on the east side of seedlings, may reduce frost damage associated with less radiative cooling.
Koa (Acacia koa) is the premier native hardwood of Hawai‘i and a dominant forest species. It provides endangered species habitat, watershed protection, and most of the timber for Hawaii's forest industry. Hawai‘i's forest industry currently relies on harvesting old-growth koa trees from remnant natural forests, and the current supply does not meet the demand.
Successful tree improvement programs rely on the ability to screen, select, and breed for specific traits. The speed at which a program achieves its goals is often increased with the help of asexual, vegetative propagation, usually in the form of rooting or grafting.
‘Ōhi‘a (Metrosideros polymorpha) is Hawaii’s most abundant native tree and the most important ecological and cultural keystone species in Hawaiian forests. A recently introduced fungal disease, caused by the vascular wilt fungus, is creating widespread mortality in ‘ōhi‘a.
Sandalwoods (Santalum spp.) grow naturally in climates ranging from warm desert in Australia, to a seasonally dry monsoon climate in India, Eastern Indonesia, and Vanuatu, to a subtropical climate without pronounced dry seasons in Hawai‘i and New Caledonia.
Koa (Acacia koa) is among the most ecologically and economically valuable hardwood tree species in Hawai‘i and is planted extensively for forest restoration. A relatively high planting density helps to ensure sufficient numbers of surviving seedlings.
Reforestation and forest restoration projects require massive quantities of seeds. Seeds of many legumes, including Acacia koa (koa) require that seeds are scarified (treatment to damage the seed coat to allow water uptake) in order to germinate.