资源环境科技发展态势分析平台

Hawai'i's most widespread native tree, 'ohi'a lehua (Metrosideros polymorpha), has been dying across large areas of Hawai'i Island mainly due to two fungal pathogens (Ceratocystis lukuohia and Ceratocystis huliohia) that cause a disease collectively known as Rapid 'Ohi'a Death (ROD). Here we examine patterns of positive detections of C. lukuohia as it has been linked to the larger mortality events across Hawai'i Island. Our analysis compares the environmental range of C. lukuohia and its spread over time through the known climatic range and distribution of 'ohi'a. Analyses show this fungal pathogen generally encompassed the core, but not the extremes of the climatic range of 'ohi'a. We further modeled the potential distribution of C. lukuohia across the Hawaiian Archipelago to estimate the risk of ROD to other islands. Given the potential for C. lukuohia to alter the structure of 'ohi'a dominated forests, we used our projected potential distribution of C. lukuohia to assess the risk of ROD to threatened and endangered plant species across Hawai'i. Many native plants are likely vulnerable to these types of large 'ohi'a mortality events: of 234 endangered native plant species considered, 147 (62.8%) have more than half of their range within current and expanding C. lukuohia suitable areas. We also found evidence that protecting habitat by fencing out introduced feral ungulates reduces the prevalence of the disease likely by reducing physical damage caused by these animals to 'ohi'a trees, a precondition for Ceratocystis infection. Given the ongoing spread of C. lukuohia, we developed a dynamic web portal to host our results online, where models and analyses are updated with new lab-confirmed detections to provide managers with a useful tool to help monitor and assess the risk of C. lukuohia as it continues to spread.