Your browser does not support JavaScript!

Mapping the LAND COVER of the dominant ecological systems

Published May 24, 2011

The first step of gap analysis is to create a land cover map that depicts the ecological systems in the area being studied. Ecological systems are defined as “groups of plant community types that tend to co-occur within landscapes with similar ecological processes, substrates and/or environmental gradients: (Comer et al. 2003). Ecological systems are used because the patterns of natural terrestrial land cover are a reflection of the physical and chemical factors that shape the environment of a given land area.

Land cover map for Florida

Vegetation communities are also determinate for overall biological diversity, because their structures and composition significantly affect species-level interactions.
Land cover is mapped using 2001 Landsat ETM+ satellite imagery from the Eros Data Center’s Multi-Resolution Land Characteristics Consortium (MRLC) program. MRLC is the federal consortium for obtaining, processing, and archiving satellite imagery. To facilitate the interpretation of the satellite imagery, we collected field data. Sufficient data were collected to assign an ecological system label to the plot. Knowing how these plots appeared in satellite imagery, enabled us to interpret the remainder of the satellite imagery.
We used a variety of other datasets to help with the land cover classification process. Digital elevation model-derived data sets (which included elevation, slope, aspect and landform) were used, along with digital data on soils, geology, stream and wetland location, point locations for rare plant communities and fire and tree harvest information. Locations of agricultural areas and developed lands were pulled in from the GAP land cover maps directly from the National Land Cover Database 2001. To read a more detailed description of the land cover mapping process, click here.
See our National Land Cover viewer to explore Land Cover data online.