Island Ecology

The last vegetation map produced for the island was by the Center for Natural Areas in the 1970's. A new vegetation map can be used to quantify the extent of various plant communities on the island, track changes in the extent of these communities, to locate future plant and wildlife study sites, and to guide management.

Management Objective:
To maintain or improve the health and natural balance of Santa Catalina Island's plant communities. To this end, locate, quantify, and track all (both widespread and limited, common and sensitive) plant communities on the island.

Methods:
Color aerial photographs were taken of Santa Catalina Island in October of 2000, and printed at a scale of 1 inch equals 400 feet (along with 9 by 9 inch contact prints). These will be used to map the vegetation by scanning the photographs and using raster GIS software to orthorectify them, then digitizing the vegetation boundaries directly in these files.

The classification systems used will be hierarchical, and incorporate both physiognomic and floristic levels. Plant communities will be mapped directly from the photographs, along with ground truthing. Plant series will need to be mapped using a combination of aerial photographs, ground mapping, and sample plots. Sample plots would be needed to characterize the series in accordance with Federal Geographic Data Committee and National Vegetation Classification standards; existing transects may potentially be used for this purpose.

Historical aerial photographs have been acquired for the years of 1994 and 1981, and will also be obtained for 1954. These photos will be used to map vegetation to the community level, and used to analyze changes in the extent and distribution of these communities.

Collection Frequency:
Aerial photographs will be commissioned and a vegetation map produced every five years from the year 2000.