Geoscience Reference
In-Depth Information
Fig. 4.5
American chestnut habitat suitability map for Mammoth Cave National Park: (
a
) - suit-
ability map for the entire park; and (
b
) - suitability map on the historically non-agricultural lands.
Areas with habitat suitability greater than 20 are defined as favorable chestnut habitats
for American chestnut was more concentrated in the north-central and northeast-
ern part of Mammoth Cave National Park. Figure
4.5a
provides a spatial reference
for future chestnut restoration. On the second map, a mask of land use history was
added (Fig.
4.5b
). Land use history was superimposed on Fig.
4.5a
, and areas clas-
sified as historical agricultural lands were masked, because most chestnut sprouts
were located on non-agricultural land. With the land use history mask, about 19%
of the areas were predicted as favorable chestnut habitat. Figure
4.5b
provides a spa-
tial reference for locating more chestnut specimens in the future. Based on the map,
there would be a low chance of finding American chestnut sprouts in the western
and southeastern portion of Mammoth Cave National Park.
4.3.2.4 Model Validation
Cross-validation was first applied to validate the chestnut habitat model. The
Continuous Boyce Index (CBI, Boyce et al.
2002
) was 0.97
±
0.03 for the
