DETERMINATION OF FOREST COMMUNITIES IN A TEMPERATE MOUNTAINOUS FOREST USING REMOTELY
SENSED AND ANCILLARY DATA OF VARYING SPATIAL RESOLUTION
Janette C. Gervin, NASA Goddard Space Flight Center, USA; H. Hugh L. Bloemer, Ohio University, USA; James O. Brumfield,
Marshall University, USA; Joseph A. Langdon, NASA Headquarters, USA; and Charles Yuill, University of West Virginia, USA
KEYWORDS: Forestry, Environment, Accuracy, Spactial, DEM/DTM, Aerial, Thematic
ABSTRACT: Techniques for identifying forest communities were explored for an area near Spruce Knob, West Virginia, containing
representative Appalachian forest communities and one of the more southerly outliers of the red spruce community. The utility of spatia
and spectral resolution in the determination of forest communities was examined by comparing classifications of digitized aircrafi
photography at 3 meter spatial resolution and of TM imagery, using the six non-thermal bands and those equivalent to color infrared
photography, at 30 meter resolution. The aircraft-based classification provided much greater detail, demonstrating a greater refinement
in response to the small characteristic distance of change in these temperate mountainous forests. The larger TM pixel averaged much of
this detail to produce a classification of more uniform classes and graduated change, which may be less representative of the surface
vegetation but nevertheless useful for studies of larger areas. The addition of the blue and mid infrared TM bands does improve the
classification when compared with the color infrared-equivalent bands of TM. The inclusion of elevation and aspect adds additional
information and capability which may result in a more accurate delineation of forest associations and composition. More work will be
required to fully develop and utilize its potential for describing and understanding forest communities.
INTRODUCTION
Importance of the temperate mountainous forest
The tropical rain forest and high latitude boreal forest are
receiving extensive study as part of the Global Change Research
Program due to their importance to global carbon cycle balances
and global climate modeling. The temperate forest is also very
important because of its effect on local and regional climate as
well as its contribution to global ecological processes.
The temperate mountainous forest presents a number of
difficulties from a remote sensing perspective because such
forests have a smaller characteristic spatial scale, both in terms of
plant communities and in terms of overall extent; have frequently
been harvested or otherwise disturbed by human activity; and
generally occur in mountainous terrains, adding the factors of
slope, aspect and elevation and their impact on reflectance and
climate. The proposed development of high spatial and spectral
resolution sensors together with the growing availability of
Digital Elevation Model (DEM) data will make it possible to
better analyze and characterize these forest communities so that
their contribution to global and local processes can be studied.
The work reported here is part of a larger project funded under a
NASA EPSCOR Grant to study patterns and periodicities in
mountainous terrain.
Description of Study Site at Spruce Knob, West Virginia
The Spruce Knob USGS 7.5 minute quadrangle in West Virginia
was chosen as the initial study site because it lies at the
intersection of the Northern Hardwood and Southern Appalachian
Forest Associations along the northeast-southwest trending
Appalachian Mountain Chain. Its forest communities are
representative of those throughout much of the Appalachians, so
techniques developed here should be widely applicable
throughout the Eastern mountainous regions. Spruce Knob also
provides one of the more southerly outliers of red spruce, a
survivor of the last glacial period. — Ongoing research (e.g.,
Adams and Stephenson, 1989; Johnson et al, 1992; and
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DeHayes, 1992) suggests that red spruce in West Virginia are
already under stress from climatic variations and other factors and
may provide an early indicator of climate change.
The mountain ridges trend northeast-southwest separated by deep
valleys and dissected by narrow, deep ravines and trellis drainage
patterns. This site includes portions of the Spruce Knob - Seneca
Rocks National Recreation Area and the surrounding
Monongehela National Forest. The forest communities change
with elevation and with aspect. Cove (1929) describes the
progression from beech-maple in the foothills through oak
hickory to spruce-birch above 4000 feet (1219 meters). Recent
work by Brannon et al. (1994), patterned after research by
Whittaker (1975) in the Great Smoky Mountains, has related the
prevalence of various species to elevation and through available
moisture to aspect. On moister slopes cove hardwoods and
hemlocks give way to northern hardwoods (beech and maple)
between 2500 and 3000 feet (762 and 914 meters), followed by
red spruce-yellow birch above 3500 feet (1067 meters) and pure
stands of red spruce above 4500 feet (1372 meters). Oaks
predominate at the lower elevations on sheltered and drier slopes,
with red spruce-yellow birch and pure red spruce at the higher
elevations. If conditions are extremely dry or exposed, pines may
be found on the slopes and heath barrens or grass balds on the
summits. Plantations of red pine have been planted in some
locations, also.
Within this study site an area surrounding The Mountain Institute,
part of an international educational and research organization
dedicated to preserving mountain environments and cultures, has
been chosen for more intensive study (Figure 1). Except for
limited harvest and grazing, this area has been largely undisturbed
for decades. A large pasture in the center is flanked by red spruce
on the east, which appear darker, and northern hardwoods on the
north, west and east. The Mountain Institute is located just north
of the largest red spruce stand east of the pasture. Red pine
plantations (also darker than the surroundings) can be found in
the northwest corner. A riparian community consisting of open
brushland with sapling trees follows Big Run on the west. What
appears to be a similar landcover can be seen in forest clearings
on the aerial photograph. The elevation ranges from 1051 meters
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B7. Vienna 1996
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