Classification Distribution Vegetation Accuracy

Tree canopy cover is between 45% to 70% with needleleaf tree cover greater than or equal to 75% of the total tree cover. The class is comparable to the Viereck et al. (1992) hierarchical levels closed needleleaf forest (IA1) and open needleleaf forest (IA2).

The dense-open spruce class occurs on low elevation (107 to 731 meters based on field data; Table 3) floodplains, toeslopes, and valley bottoms primarily north of the Alaska Range within Denali National Park and Preserve. It generally occurs as small to medium size patches on well-drained, loamy or sandy soils. These sites have little (5 to 10 degrees) to no slope, and generally occur on South and West aspects. Disturbance is typically from alluvial and fire processes. They are commonly found in the Toklat drainage, west of the Kantishna Hills, and the toeslopes of the Alaska Range in the west-central part of the park. Although it occurs in all ecoregions, it is more prevalent in the Kuskokwim-alluvial fans and flood plains ecoregion than other ecoregions (Tables 4a and 4b; Clark 1998). The dense-open spruce class covers 0.8% (50,359 acres) of Denali National Park and Preserve (Table 5).

Picea glauca or Picea mariana cover ranges from 45% to 70%. Tree height can reach greater than 20 meters. Larix laricina, alders (such as Alnus crispa) and willows (such as Salix planifolia) occur in canopy breaks along with ericaceous shrubs (such as Arctostaphylos rubra, Vaccinium vitis-idaea, and V. uliginosum). There frequently is a high graminoid component associated with these sites. Mosses are common as well as small amounts of lichen. The dense-open spruce class is typically interspersed with other spruce types such as the open-woodland spruce and stunted spruce landcover classes.

The producer’s accuracy for the dense-open spruce class is 87.9%, with a user’s accuracy of 69.4%. Most of the errors of commission and omission are due to confusion with the open-woodland spruce class. All accuracies are based on the 25-class landcover map at a 2-acre mapping unit prior to the digital integration of the burn mask.