|
using the Patch Analyst (Fig. 15). Forest polvgons containing
hemlock were reclassed to pure hemlock and hemlock mixed
with other tree species. Patch-level landscape metrics
calculated using hemlock polygons show interpreter
differences were minimal, while edge density and mean
shape index metrics were significantly lower for exterior
quads (WECO and GATL) having more human influence
compared to interior quads (THMO and SIBA) (Fig. 16 and
17).
Wear Cove : Gatlinburg | :
[err Ce
| { Interpreter # #2 2b
m1 Interpreter # #1}
Thunderhead
p Mountain ;
.. Silers Bald
Figure 11. Overstory vegetation in the Wear Cove and
Thunderhead Mountain quadrangles of Great Smoky
Mountains National Park were mapped by Interpreter #1,
while Interpreter #2 mapped vegetation in Gatlinburg and
Silers Bald.
p—— a ei Re remet
| Human Influence | |
Wear Goua MA “Gatlinburg
[rm DER
| Interior Old Growth |
Thunderhead ei Stier Bald
: Mountain ed
Figure 12. Overstory vegetation in the Wear Cove and
Gatlinburg quadrangles of Great Smoky Mountains National
Park are subject to greater human influence because they are
located at the edge of the park boundary, while vegetation in
the interior Thunderhead Mountain and Silers Bald quads is
more protected from human impacts.
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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV. Part B4. Istanbul 2004
Landscape Level Landscape Metrics
Shannon's Diversity Index
m
Shannon's Diversity Index
WECO GATL SIBA THMO
Figure 13. At the landscape level, the Shannon's Diversity
Index was slightly lower for exterior quads (WECO and
GATL). Interpreter differences were not significant.
Patch Level Landscape Metrics
M eei rn Cr reale y Theme = E am |
p * QE ,8N-U se diagonals clumping method |
+
Figure 14. Overstory vegetation polygons in vector format
were converted to patches in a raster grid for computation of
patch level landscape metrics.
Reclass to Isolate Hemlock
Figure 15. Reclassification of overstory vegetation isolated
forest patches containing pure hemlock stands and mixed
hemlock/hardwood communities.
4. SUMMARY
In summary, GIS analyses and visualization techniques were
used to assess vegetation patterns in Great Smoky Mountains
National Park vegetation community distributions. Overlay
analyses of vegetation, elevation, slope and aspect resulted in
range and variance statistics that define vegetation
distributions related to terrain factors. Rule-based modeling
of overstory and understory vegetation produced fuel class
data sets for the park that, in turn, can be used to model fire
behavior, plan fire management tactics and assess the risk of
future fires. Landscape metrics also were used to investigate
patch characteristics of diversity, shape and edge density.