Clay Trauernicht (Natural Resources and Environmental Management) is lead author on a paper recently published in the journal Forest Ecology and Management, “Active Restoration Enhances Recovery of a Hawaiian Mesic Forest After Fire.” The paper discusses the results of long-term plots that he worked to install after a fire in the Wai‘anae mountains in 2004 and re-sampled last year in collaboration with colleagues in the Department of Botany. As the abstract explains, there is little published research on post-fire recovery of native Hawaiian forest outside of Hawaii Volcanoes National Park. The paper examines the response of a Hawaiian mesic forest on O‘ahu to fire and restoration efforts over a 14-year period (2004-2017).
Natural regeneration and outplantings of the native tree Acacia koa after the fire formed a closed-canopy forest in just 14 years. However, other naturally regenerating natives declined, and nonnative plants currently dominate both the understory vegetation and tree species regeneration in the burned area. Although outplanting of koa and other native species significantly increased the native component of post-fire vegetation, longer-term recovery to native forest will require further intervention.
Koa’s capacity to regenerate after fire provides some level of resilience for native forests, but pure koa stands tend to give way to mixed-species canopies over time. Therefore, although koa remains a key species for native forest restoration and recovery efforts, active outplanting of other native tree species needs to be considered for long-term native forest establishment after fire disturbance.