Arctic GIS Workshop Poster Abstract
Vegetation Characteristics Derived from an Integrated Vegetation Complex Map for the Canadian Arctic
The Canadian Arctic Vegetation Map is a component of the Circumpolar Arctic Vegetation Map (CAVM) project, and will be an important part of a circumpolar geobotanical database available via a web of GIS sites. The goal of the CAVM project is to map the vegetation and associated characteristics of the circumpolar region. Individual mapping efforts ongoing in Canada, Norway, Greenland, Russian, Iceland and the United States are using uniform methods to integrate information on soils, bedrock and surficial geology, hydrology, remotely-sensed vegetation classification, Normalized Difference of Vegetation Index (NDVI), previous vegetation studies, and regional expertise of the mapping scientists. All mapping uses the same base map, a composite AVHRR false color infrared image of the maximum reflectance of each 1km2 pixel of 1993 and 1995 data. Mapped landscape units are linked to a vegetation description, associated properties, and descriptive literature through a series of lookup tables. These tables have been used to create a vegetation map as well as derived maps of vegetation properties including dominant plant functional type, horizontal vegetation cover, biomass, and annual net primary productivity.
The Canada maps provide examples of some of the types of products that will be available. Vegetation characteristics including dominant plant functional type, horizontal structure, biomass, and annual net primary productivity of the Canadian Arctic were mapped by linking biophysical attributes with the dominant vegetation type. Lookup tables created in ARCINFO linked these attributes and allow the mapping and determination of the areal extent of each attribute category. Nineteen land cover types, including glaciers, fresh water, and 17 vegetation complexes were mapped. Plant functional types vary along latitudinal and elevational gradients, and range from low deciduous shrub (< 15cm height) to cushion forbs and bryophytes beyond the northern limit of woody plants. The horizontal vegetation structure decreases with latitude and elevation, and on extremely coarse calcareous or acidic substrates. Roughly 1/3 of the region is barren or semi-barren with less than 50% vegetation cover. Biomass and annual net primary productivity are also strongly controlled by climate, substrate and topography with approximately 90% of the total biomass for the region concentrated in the more productive Low Arctic, on just over 30% of the land surface area.