CT Land Cover and Change (1985 to 2015)
Changing Landscape is a remote sensing-based land cover study that charts landscape changes in Connecticut and portions of New York. It covers the 30-year period from 1985 to 2015 (with in-between dates of 1990, 1995, 2002, 2006 and 2010).
The Connecticut Land Cover Viewer contains all dates of land cover as well as Change To, Change From, and Forest Fragmentation. It also has many layers where towns are colored based on a particular land cover. For example, forest cover and forest cover change is shown by town. Open the viewer in it's own window and then use the layer list icon to explore.
CT Forest Fragmentation
The Forest Fragmentation map is a derivative of the land cover. First, land cover classes are aggregated into three categories: fragmenting classes, forest classes, and non-fragmenting classes. For each date, the 12 category land cover was reclassified into three categories:
- fragmenting classes (developed, turf & grass, other grasses, agricultural fields, barren land, utility corridors),
- forest classes (deciduous forest, coniferous forest, forested wetland),
- non-fragmenting classes (water, non-forested wetland, tidal wetland all of which will not affect the fragmentation analysis).
The tool then uses the fragmenting land cover pixels to re-classify the forest land cover pixels into fragmentation classes, ranging from the most degraded (patch and edge) to least degraded (core).
Forest Fragmentation on CT ECO
In the Viewer, look for the following layers: 1985 Forest Fragmentation, 2015 Forest Fragmentation.
On the Services page, look for the CT Forest Fragmentation category.
On the Download page, look for Forest Fragmentation under Connecticut+.
Landscape Fragmentation Tool
The forest fragmentation analysis is based on the following research:
- Vogt, P., K. Riitters, C. Estrenguil, J. Kozak, T. Wade, J. Wickham. 2007. Mapping spatial patterns with morphological image processing. Landscape Ecology 22: 171-177
The fragmentation of forests and other natural land covers degrades these resources in terms of both their ecological and economic value. The Landscape Fragmentation Tool is used to measure fragmentation in a landscape based on land cover data.
The Landscape Fragmentation Tool v2.0 is based on a procedure to map forest fragmentation that was developed in a recent study (2007) that included participants from the by the U.S. Forest Service and U.S. EPA. The procedures developed are believed to be more consistent and reliable than previous methods for mapping fragmentation at the landscape level. The tool was developed by CLEAR staff and requires the spatial analyst extension for ArcGIS 9.2.
NOTICE: The Landscape Fragmentation Tool v2.0 (LFT v2.0) was developed based on research by P. Vogt et. al. (2007). Since that time, there has been further development in the procedure by Vogt of the European Commission Joint Research Centre, in the form of the Morphological Spatial Pattern Analysis (MSPA) tool. The MSPA provides a customized sequence of mathematical morphological operators targeted at describing the geometry and connectivity of landscape features of interest. Compared to the LFT v2.0, the final version of MSPA provides more feature classes, and includes the detection of border and core openings.
For more information about MSPA and to download the tool visit:
http://forest.jrc.ec.europa.eu/download/software/guidos/mspa/
Edge Width
The edge width parameter is the distance over which the fragmented land cover type of interest (i.e. forest) can be degraded by the fragmenting land cover types (i.e. development, agricultural fields, etc). The literature indicates that the edge width varies by the species or issue of interest.
- Edge widths reported in the ecology literature range from 50 meters to several hundred meters depending on the issue of interest.
- An edge width of 100 meters (330 feet) is often used for general purposes analysis.
- The edge width parameter determines the width of the edge and perforated forest zones as well as the thickness of patches.