These metrics usually are best considered as representing landscape configuration, In addition to these primary metrics, FRAGSTATS also summarizes the. There is a wide variety of landscape metrics that have been developed and applied for many years. These metrics help us to quantify physical characteristics on. every patch is counted; FRAGSTATS does not sample patches from the . For a categorized list of FRAGSTATS output metrics see the FRAGSTATS Metrics.
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Furthermore, mean patch size represents the average condition. These metrics usually are best considered as representing landscape configuration, even though they are not spatially explicit measures.
In many ecological applications, second-order statistics, such as the variation in patch size, may convey more useful information than first-order statistics, such as mean patch size. Fragstats and Landscape Metrics Print There is a wide variety of fraagstats metrics that have been developed and applied for many years. As noted above, the area AREA of each patch comprising a landscape mosaic is perhaps the single most important and useful piece of information contained in the landscape.
Nevertheless, patch size coefficient of variation also can be misleading with regards to landscape structure in the absence of information on the number of patches or patch density and other structural characteristics. However, when comparing classes or landscapes of identical metfics, total edge and edge density are completely redundant.
Fragstats and Landscape Metrics | GEOG Conservation GIS
This index is similar to the habitat diversity index proposed by Pattonexcept that we apply the index at the class level as well. In addition, although mean patch size is derived from the number of patches, it does not convey any information about how many patches are present. In this case, the interpretations of landscape pattern would be very different, even though absolute variation is the same.
For example, the distribution of patch area AREA is summarized by its mean and variability. At the class and landscape levels, edge can be quantified in other ways.
Note, shape complexity and aggregation or contagion are closely related concepts. I encourage you to explore it!
The Patch Analystan Esri extension, contains many of the Fragstat metrics. These summary measures provide a way to characterize the distribution of area among patches at the class or landscape level.
For example, two landscapes could have the same number and size distribution of patches for a given class and thus fragatats the same mean patch size; yet, if total landscape area differed, patch density could be very different between landscapes.
These metrics help us to quantify physical characteristics on the ground and connect them to ecological processes.
Variability in patch size measures a key aspect of landscape heterogeneity that is not captured by mean patch size and other first-order statistics. Alternatively, two landscapes could have the same number of patches and total landscape area and thus have the same patch density; yet, if class area differed, mean patch size could be very different between landscapes. Do Go to the Fragstats webpage. Area metrics quantify landscape composition, not landscape configuration.
Fragstats and Landscape Metrics
Mefrics is identical to the shape index at the patch level SHAPEexcept that it is based on class area and the associated class perimeter at the class level and the total landscape area and all edges at the landscape level. There are metrics that have been identified that inform about the landscape in its entirety as well as metrics that break down each land cover class within the defined landscape.
For example, the number or density of patches may determine the number of subpopulations in a spatially-dispersed population, or metapopulation, for species exclusively associated with that habitat type. Radius of gyration GYRATE is a measure of patch extent; that is, how far across the landscape a patch extends its reach. Although both indices may be useful for “describing” 1 or more landscapes, they would never be used simultaneously in a statistical analysis of landscape structure.
Edge metrics metriics are best considered as representing landscape configuration, even though they are not spatially explicit at all. Mean patch size at the class level is a function of the number of patches in the class and total ffagstats area.
For example, a mean patch size of 10 ha could represent a class with 5 ha patches or a class with 2- 3- 5-,and ha patches, metrrics this difference could be important ecologically.
It may be more fragstatss to inspect the actual distribution itself, rather than relying on summary statistics such as these that make assumptions about the distribution and therefore can be misleading. For this species, late-seral forest area might be a good index of habitat suitability within landscapes the size of spotted owl home ranges Lehmkuhl and Raphael When aggregated at the class or landscape level, radius of gyration provides a measure of landscape connectivity known as correlation length that represents the average traversability of the landscape for an organism that is confined to remain within a single patch.
Skip to main content. There is a wide variety of landscape metrics that have been developed and applied fragstts many years. For example, northern spotted owls have minimum area requirements for late-seral forest that varies geographically; yet, individual spotted owls use late-seral forest that may be distributed among many patches Forsman et al. At the landscape level, metrics are tabulated from within a 1 km radius circle around each site.