Collaborative Research: Bridging the Space-Time Continuum to Investigate How Biodiversity Scales Across Subterranean Systems

University Of Hawaii, Honolulu

Investigators

Abstract

Many cave-dwelling animals have evolved striking traits, such as reduced or lost eyes, lost pigmentation, elongated limbs, and altered metabolism associated with colonizing a range of unique subsurface habitats. Previous studies of individual cave-adapted species from the same locations suggest that complex biological interactions within and among species have occurred over time. However, it is unclear how long it takes to form a cave ecosystem and how ecosystem functions are maintained through time. On Hawaiʻi Island, continuous volcanic activities over hundreds of thousands of years created subterranean habitats, known as lava tubes, that are of different geologic ages and represent distinct eco-evo “islands.” Diverse yet understudied communities of cave-adapted arthropod species live in these Hawaiian lava tubes and are sustained by the roots of the native pioneer tree, ōhi'a. The project will result in several major advancements, including documenting and describing new species occurrences and distributions, as well as obtaining ecological and genetic data for the lava tubes and species, both of which will serve as significant breakthroughs for Hawaiʻi, where island biodiversity loss has reached unprecedented levels. The project places a strong emphasis on the local Native Hawaiian community, and will support educating the next generation of diverse scientists and the public about integrative biological research by including: (1) year-long cross-disciplinary research internships for undergraduate students in Hawaiʻi, (2) collaborative training for students and researchers in biodiversity, ecology, and molecular genetics, and (3) renovation of the Hawaiian Cave Arthropod Exhibit at the Bernice Pauahi Bishop Museum in Honolulu, Hawaiʻi, which will include the development of public outreach programs and K-12 educational materials. This project uses an integrative approach to understand how ecological interactions and evolutionary chance generate biodiversity and support the taxonomic, functional, and phylogenetic diversity of subterranean arthropod communities across different spatial and geological scales. With the potential to discover more subterranean arthropod diversity, this research involves systematic biological surveys of under- or unexplored lava tubes on Hawaiʻi Island to determine community-level diversity patterns that can be compared to estimated species richness and alpha (within community) and beta (among communities) diversity. Ecological niches and species interactions that define functional diversity will be evaluated using stable isotope ratio analysis of arthropods and diet resources. Phylogenetic diversities will determine the extent of parallel diversification across lineages, communities, and niches. The uncovered ecological and evolutionary relationships establish the importance of ecosystem-level feedbacks among different diversity-regulating processes (i.e., food web interactions, population dynamics, speciation) that govern subterranean ecosystem creation and maintenance through time. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.