Envisioning the future: vegetation mapping based on the National Vegetation Classification as a basis for spatially explicit habitat modeling and conservation planning

Background/Question/Methods

Vegetation types are increasingly used as biodiversity targets for terrestrial conservation planning and reserve design. Vegetation maps frequently form the basis of spatially explicit wildlife habitat modeling. As described in the talks in this session, the US National Vegetation Classification (NVC), as a classification standard based on quantitative analysis of plot data, supports development of useful and reliable vegetation maps at multiple scales. Vegetation classification provides descriptions of plant community composition and structure. Vegetation mapping delineates geographical entities corresponding to the classification. Presentations in this session advocate the development of multi-attribute vegetation maps that include information about the physical environment, land use and disturbance.

I review recent vegetation mapping efforts in order to identify emerging trends in: 1) the separate versus integrated development of classifications and maps; 2) single versus multiple attribute vegetation mapping; 3) analyses based on these mapping efforts; and, 4) emerging technologies that will enable vegetation mapping in the future.

Ongoing efforts, as presented in this session, suggest that integrating plot data from different sources, as the basis for classification, is feasible and desirable. Integrated development of the NVC with vegetation mapping can increase the usefulness of both the classification and the map for conservation planning.

Results/Conclusions

Several national efforts are worth noting. Australia has established a national vegetation information system that brings together all vegetation mapping information, developed using a variety of methods, data sources, scales and time periods. South Africa recently developed a national vegetation map, and although it was a single effort, different data sources and methods were employed in different regions, ranging from manual delineation of map units to multispectral classification of satellite imagery. In the US, the USGS has compiled vegetation maps at the national scale through the National Gap Analysis Program based on a classification of terrestrial ecological systems. These examples suggest a trend at larger spatial extents to rely on preexisting information and to define classes based on multiple attributes. It is challenging to integrate mapped information from disparate sources. This would be facilitated by the establishment of robust and scale-dependent vegetation mapping standards.

Although there are tradeoffs between spatial resolution and spatial extent for any type of mapping, new technologies and data sources are allowing spatially and categorically fine-scale vegetation information to be mapped for large areas.  These enabling technologies include low-cost GPS, Google Earth, high spatial resolution multispectral imagery, LIDAR, and high resolution digital terrain data.