Arthropod biodiversity estimates for three native subalpine plant species on Hawaii’s Maunakea volcano

Insects and other arthropods are among the most abundant and diverse animals on Earth. This is especially true in Hawaii where they constitute the majority of the islands’ endemic fauna and play important roles in Hawaii’s ecosystem functions. Although arthropods are omnipresent in nearly every terrestrial ecosystem, studying these animals is challenging. Detection and identification is difficult because many insect species are small and very mobile with immense population sizes, complex morphologies and diverse life histories. Moreover, their habitats may be in harsh climates and terrain that is difficult to access. We have catalogued nearly 7,000 individual insect records from 2012-2015 as the baseline biodiversity estimate for three prominent native plant species (Chenopodium oahuense, Geranium cuneatum, and Sophora chrysophylla) in the 2,800m elevation subalpine region of the Maunakea Volcano on Hawaii Island. To analyze these data, we used statistical software (EstimateS 9.0) to estimate and compare arthropod abundance and species richness on these three plant species. The ultimate goal of our research is to demonstrate the use of limited empirical data to develop an alternative, targeted sampling approach that uses species accumulation curves and sequential sampling plans to offset the challenges of arthropod sampling and diversity estimates for Maunakea’s subalpine plants. By developing quantitative models that facilitate arthropod monitoring and annual comparisons, our research results will help the Office of Maunakea Management minimize the cost and effort required to monitor and protect rare endemic species and mitigate invasive species effects in Maunakea’s subalpine environment.