The Virginia Natural Landscape Assessment (VANLA), an ecological component of the VCLNA, is a landscape-scale GIS analysis for identifying, prioritizing, and linking natural habitats in Virginia . Using land cover data derived from satellite imagery, the VANLA identifies unfragmented natural habitats called cores, which are large patches of natural land cover (mainly upland forests and forested wetlands, but also included are marshes, beaches, and dunes) with at least 100 acres of interior conditions. Interior conditions begin 100 meters inward from the edges of the cores. Large, medium, and small cores have been identified for the entire Commonwealth (Figure 1), as well as a smaller feature type called "habitat fragments" that have only 10 to 99 acres of interior and may be important in urban localities where few large patches of natural land remain. Cores provide habitat for a wide range of species, from interior-dependent forest species to habitat generalist, as well as species that utilize marsh, dune, and beach habitats. Cores also provide benefits in terms of open space, recreation, water quality (including drinking water protection), and carbon sequestration, along with the associated economic benefits of these functions. Cores and habitat fragments are supported and buffered by natural landscape blocks, which are aggregations of cores, habitat fragments, and adjacent natural lands. Natural landscape blocks can be used as coarse analysis units for broad geographic areas.
Cores, habitat fragments, and natural landscape blocks have been mapped for the entire study area. Dozens of prioritization attributes have been assigned to the cores and habitat fragments. An example of one prioritization attribute, the number of natural heritage elements (i.e. rare species or ecological communities) per core or habitat fragment, can be viewed in Figure 2. The cores layer was built with many separate prioritization attributes to allow end users to quickly view attributes of interest and to facilitate incorporation of separate attributes into decision support systems. Modeling is underway now to synthesize ecological significance from a subset of the prioritization attributes. This synthesis will result in a new prioritization attribute that will be used to rank cores and habitat fragments by ecological significance. The highest-ranked cores will be connected by corridors of natural land cover to create a core and corridor network for the Commonwealth.
VCLNA products will be used by VLCF, state and federal agencies, and other conservation partners for land and resource conservation and habitat restoration. The data also will be distributed to localities to be used in local and regional planning efforts.
Figure 1: 
The Coastal Zone Natural Landscape Assessment
The Virginia Department of Conservation and Recreation (DCR), with funding assistance from the Virginia Coastal Program of the Department of Environmental Quality, the Department of Forestry, and the Virginia Land Conservation Foundation, has completed a pilot Virginia Natural Landscape Assessment for Virginia's Coastal Resources Management Area, those counties and cities that touch on tidal waters. DCR built on the GIS ecological model used for the Chesapeake Bay Program's Resource Lands Assessment Ecological Assessment, modifying methodology, adjusting weights, and adding data to tailor them specifically for Virginia interests. Of particular significance is the use of land cover data based on year 2000 satellite imagery instead of the 1992 imagery used in the CBP product. Results of this pilot can be viewed below (see Figure 3).
Figure 3: 
Click on any area of the image to zoom into greater detail
The primary focus of the VCLNA Natural Landscape Assessment for the Coastal Zone is ecological prioritization - which are the most important natural, unfragmented lands ("Cores") based on considerations of biological and ecological value and integrity? Click here for more information about the significance of habitat fragmentation . Natural Landscape Blocks have also been identified - natural lands with relatively little human disturbance that surround, buffer, and support the Cores. Corridors connecting the highest priority Cores were developed by identifying the shortest distances through the most suitable habitats. DCR has also used data on development pressures (from CBP's Resource Lands Assessment) to identify which cores are most at risk of loss or degradation.
Based on the lessons learned during the pilot analysis and comments received from localities and other end users, we are refining the statewide VANLA methodology, including the addition of the habitat fragment feature type that is important in the more developed localities that have few or no cores. Another improvement is in the use of statewide land cover data that were all processed by the same research group.
Coastal Zone NLA Atlas
Atlases were produced for the pilot analysis - one comprehensive Atlas for the entire Coastal Zone and 8 regional Atlases for each of the coastal Planning Districts. The contents of these Atlases are available online and on CD by request and include:
VANLA Atlas
A comprehensive atlas, probably in multiply volumes, will be produced with maps for all the Planning Districts in the Commonwealth. The contents of these atlases will be similar to those resulting from the CZNLA. Additional maps will be available online and on CD by request.Application of the VANLA
Page last updated 4/06.
