Skip to main content

James D Jacobi

thumbnail
This file contains the raw data collected as part of a vegetation monitoring study that was conducted to assess the changes in plant species frequency inside and outside a fenced exclosure, constructed to eliminate browsing and grazing by feral goats, from 2009-2014 in the US Geological Survey's Kawela research site on the island of Molokai, Hawaii.
This project snapshot provides a brief overview of the project "Assessing the Potential Effects of Climate Change on Vegetation in Hawai`i Volcanoes National Park".
thumbnail
We analyzed very-high-resolution imagery to assess status of Metrosideros polymorpha forests across an 83,603 hectare study area that experienced extensive canopy dieback in the 1970s on the eastern side of the island of Hawaii. Using GIS we generated 1170 virtual vegetation plots with a 100 m radius; 541 plots in areas mapped in 1977 with trees dead or mostly defoliated (dieback), and 629 plots in adjacent wet forest habitat, previously mapped as non-dieback condition. In each plot we estimated the percent of M. polymorpha trees dead or mostly defoliated, and percent of trees with healthy crowns. These results were combined with habitat data to produce a spatial model depicting probability of canopy dieback within...
thumbnail
This layer depicts the status, or degree of disturbance, to plant communities on the main Hawaiian Islands. To more precisely identify areas where native species may presently be found, a map was generated that considers the following three categories of habitat quality: High, areas dominated by native vegetation; Medium, areas dominated by nonnative vegetation; and Low, highly modified landscapes. The primary source for mapping these three categories is the HIGAP land-cover classification (Gon, 2006). The High category includes all HIGAP land-cover classes that are considered to be either native dominated or mixed native and nonnative in order to represent those areas that have substantial native-species composition....
This downloadable PDF research feature summarizes the Pacific Islands Climate Science Center-supported project "Modeling Climate-Driven Changes to Dominant Vegetation in the Hawaiian Islands".
View more...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.