Please use this identifier to cite or link to this item: http://hdl.handle.net/10790/2685

Rapid assessment of vegetation at six potential `Alala release sites on the island of Hawai`i

Item Summary

Title: Rapid assessment of vegetation at six potential `Alala release sites on the island of Hawai`i
Authors: Price, John P.
Jacobi, James D.
Keywords: Endangered species
Extinct animals
Hawaii
Bird release
Habitat (Ecology)
Issue Date: Oct 2007
Series/Report no.: TR-HCSU;006
Related To: http://hilo.hawaii.edu/hcsu/publications.php
Abstract: The U.S Fish and Wildlife Service (FWS), as part of its participation in the effort to recover the endangered ‘Alalā (Corvus hawaiiensis), is supporting efforts by the ‘Alalā Recovery Team (ART) to rank areas for suitability as reintroduction sites for this species. A part of this ranking exercise is determination of the current state of the vegetation present at the sites. Although some of these sites have been surveyed using various
methods in the recent past, specific, comparable measurements of key aspects of the plant communities are needed for ranking sites for ‘Alalā recovery.
Here we summarize new and compiled data for each of the release sites that address the current status and potential recovery of the tree canopy and understory vegetation relative to potential suitability for ‘Alalā release. This project focused on two objectives: 1) Assess the current status and distribution of forest canopy cover based on an analysis of recent satellite imagery and other spatial datasets, and 2) Collect new
field data from the six potential release sites to provide quantitative information on the status of the vegetation, with particular focus on density and species composition of plants used by ‘Alalā as food, overall density of forest understory, and degree of closure of tree canopy. The field data also served as ground-truth points for the spatial analysis. The methods of assessing habitat potential for ‘Alalā recovery presented here
represent a simple measure of vegetation attributes taken from a limited number of plots within each study area. A primary problem is in attempting to summarize large study areas that incorporate considerable variation in climate, substrate, and land use history.
An examination of several versions of the preferred food species richness value ranks the two Ka‘ū study sites first and second. This study does not consider the amount of fruit produced by different species, and therefore it is possible that some additional weighting of preferred food plants might better quantify food resource availability in different landscapes. We also assessed continuity of forest units with other similar habitats outside the study areas, the amount of site disturbance as indicated by
percent cover by alien grass species, as well as several other combinations of variables that may help in ranking the sites.
Pages/Duration: 47
URI/DOI: http://hdl.handle.net/10790/2685
Appears in Collections:Hawaii Cooperative Studies Unit (HCSU)



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