Ecological data obtained from
field-based plots can provide researchers with detailed information about
ecosystem structure and function.
However, these data typically represent processes that occur over small
spatial areas and short time scales.
Accordingly, it is difficult to extrapolate these data to patterns and
processes that take place at regional scales or over several years. Satellite-derived imagery can provide a means
to explore environmental variables at broad scales. The main objective of this study was to
conduct a landscape-scale ecological assessment of a rapidly-developing area of
West Georgia, in order to assess indicators of
ecosystem health and detect multi-temporal changes in the area. Indicator variables included in the
assessment were: population density and change, road density, proportion of stream
that has roads within 30 meters, proportion of area that has agriculture on
slopes >3%, proportion of stream with adjacent agriculture, proportion of stream
with adjacent forest cover, percent forest land cover, forest patch density,
and Shannon's Diversity Index. Cluster
analysis was used to combine these indicator variables into different
groups. Cluster means were then used to
rank different areas of the four-county region according to relative cumulative
ecological impact. Our results indicate
that landscape variables are highly correlated to field measurements, and areas
observed to have greater adverse impact scores corroborate the findings from
our plot-level forest condition assessments.
These findings suggest that satellite imagery can be used to accurately
predict areas of adverse ecological impact and could be used to monitor forest
health in a time- and cost-efficient manner.