ESA 2014: GRS NVCS Mapping - The Future is Now !!
Recently completed National Vegetation Classification (NVCS) vegetation/land cover map data sets for Lassen Volcanic National Park and Redwood National and State Parks include species-specific cover mapping and NVCS detailed associations and alliances. These new map data sets represent the future of NVCS vegetation mapping and should be considered "state-of-the-art."
On August 14, 2014, Dr. Janet Franklin of Arizona State University presented a summary of "the state of the art and the likely progress of uses of [National Vegetation Classification System] vegetation mapping." Her presentation was the final portion of the Mapping with the National Vegetation Classification: Purpose, Value, and Method session at the Ecological Society of America Annual Meeting held in Sacramento, CA that was organized by Todd Keeler-Wolf1 and Julie Evens2.
In her summary slide Dr. Franklin showed a progression through time representing the idea that in the past lower resolution imagery provided more generalized NVCS types and that presently "new technologies and data sources," including higher resolution imagery enabled the development of "categorically fine-scale vegetation information [NVCS classes]. She predicted that sometime in the future, species-specific cover modeling would become available due to improvements in technology, imagery, and processing.
Geographic Resource Solutions (GRS) has been successfully mapping species-specific cover as a continuous variable and detailed types, including NVCS types, for the past 15 years as shown in the following maps. One map shows the extent and magnitude of the cover of Abies concolor while the other shows the extent and magnitude of Abies magnifica. These cover maps do NOT represent mutually exclusive areas. A cover map may be generated from a DCMM map data set for any species or other landscape feature.
In addition, the NVCS detailed and generalized types may also be mapped. Using their proprietary Discrete Classification Mapping Methodology (DCMM), GRS has now mapped nearly 50-million acres in Northern California, the Pacific Northwest, Alaska, and British Columbia. Other national parks mapped in this manner include Katmai National Park & Preserve and Wrangell-St. Elias National Park & Preserve in Alaska.
Ken Stumpf of GRS, who attended the ESA session, believes "the ability to map species-specific cover is not related to the higher resolution of today's imagery because you don't see the species-specific cover and other detailed landscape characteristics in the imagery. You see them on the ground when you collect your field data which is used to describe the different plant communities that you wish to map. Species cover is mapped by being able to properly associate the different levels and types of cover information to different spectral patterns recognized in the imagery, not by actually seeing these cover features in the imagery."
Ken also noted "if the higher resolution imagery were the answer to generating more detail and being able to map or model cover, we could have done this long ago, as the high resolution imagery is simply an orthorectified version of aerial photography, but with a little less detail than the aerial photography. We've had aerial photography, including false color infrared images, since I was in school back in the early 1970's. Segmentation may be used to process this information and give the perception it is doing something new, but it is simply replacing the photointerpreter who used to draw the type boundaries on the photos with an automated process. The issue still comes down to whether you can properly and accurately associate the many different plant community cover features you see on the ground with the imagery used to represent the area you are mapping."
For additional information about GRS, the Discrete Classification Mapping Methodology, or past National Park Service NVCS mapping projects contact Ken Stumpf at GRS.
1 California Department of Fish and Wildlife.
2 California Native Plant Society.