Plants in Hawai‘i, as elsewhere, have certain environmental requirements from their habitats which can be affected by changes in climatic conditions and resource competition with other species. It is important to understand these requirements of targeted conservation species as well as how they may respond to likely climate changes. Using species abundance and over 35 years of data from thousands of locations in Hawaii, a research team, supported by the Pacific Islands Climate Science Center, constructed maps which detail plant community characteristics related to aspects of the climate.

The team focused on 15 species—10 native and 5 invasive plant species—selected based on their importance in communities and prevalence in the data sets. Drawing on species’ environmental preferences and climate projections for the Hawaiian Islands, the team produced estimates for best future habitats for each species. The map below illustrates where ‘ōhia (Metrosideros polymorpha), a key tree species within Hawaiian native forests, is likely to decrease or increase on Maui Island within future climate projections. The models suggest that ‘ōhia will expand into higher elevations, although the similar expansion of invasive species emphasizes the need to understand the ecological responses of different species through studies of dispersal and growth rates.  

For conservation managers, this information can help inform how to focus conservation efforts for native and threatened wildlife, such as forest birds and insects, which often depend on native plant communities to thrive. Managers may also determine where species abundances overlap in these projections to pinpoint biodiversity hotspots and greater habitat quality for restoration and conservation priorities.

Just as important are insights to the potential spread of invasive species to conservation areas and new habitats such as abandoned agricultural lands. Conservation managers in 

Hawaii spend a great deal of resources controlling invasive species populations, so being able to anticipate future populations could focus those efforts, saving time, money, and human resources alike.

Together with a consideration of species response characteristics, these models can combine to promote multi-species landscape management for current and future climate scenarios. Managers can further utilize these models to support ecosystem resilience to climate change across the Hawaiian Islands.

This project was supported by the Department of Interior Pacific Islands Climate Science Center. For more information, please contact Jonathan Price (jpprice@hawaii.edu) or James Jacobi (jjacobi@usgs.gov) or visit the online project page.