NOTICE: Land cover datasets used for USA and Canada are of differing
spatial characteristics and were processed using different criteria (see
metadata). Thus, caution should be exercised when making comparisons
between the metrics of the USA and Canada.
Measure Amount of plant and animal habitat dissection in the Great Lakes Basin.
Purpose This metric assesses the amount and distribution of natural habitat remaining
within the Great Lakes Basin, and is used to infer the effects of human activities (e.g., housing,
agriculture, flood control, and recreation) or other natural events on habitat needed to support fish
and wildlife species.
Features This metric offers information on the presence, location, predominance, and
fragmentation of habitat in the Great Lakes Basin, as demonstrated by the use of remote-sensing data,
GIS data, and/or field observations. This indicator can be tracked over time if necessary.
Limitations To conduct such measures at a broad scale, the relationships between land
cover and the suitability/vulnerability of habitat for particular species need to be verified. This
measure will need to be validated fully with thorough field sampling data and sufficient a priori
knowledge of such endpoints and ecological mechanisms.
Interpretation Habitat suitability/vulnerability can be more thoroughly explored and
explained if it is linked to the physiology and sociobiology of the species being mapped. Interpretation
of this indicator may be correlated with other metrics and their patterns across the Great Lakes, and
such interpretation may vary as a result of the specificity of land cover information and the
contemporaneous nature of the data. Thus, more detailed land cover specificity is required, and is
currently under development by EPA/ORD.
Comments A thorough field-sampling protocol, properly validated geographic information,
and other remote-sensing-based data could lead to successful development of habitat
fragmentation/configuration as an indicator of Great Lakes ecosystem function and vulnerability in the
region. Such an indicator could be applied to select sites, but would be most effective if used at a
regional or basin-wide scale.
Metric Maps The Great Lakes Basin is mapped
for the presence, fragmentation, and configuration of wetland and forest land cover using remote-sensing
based geographic information, and may be analyzed in the context of habitat suitability and habitat
vulnerability for a variety of plant and animal species. For example, highly fragmented wetlands or
forests may provide greater edge areas for the influx of invasive organisms. Fragmentation
can also lead to the loss of core patch areas that may be critical habitat for organisms that are
sensitive to edge disturbances.