The BICM program has developed two habitat classification schemes, which include a detailed 15-class habitat scheme and a general eight-class habitat scheme.
The detailed scheme was developed specifically for this habitat mapping effort (that is, 2008 and 2015/2016) and builds off the classification scheme used in previous BICM habitat mapping efforts (Fearnley and others, 2009). The additional classes developed in the detailed scheme are primarily used to further delineate various dune habitats, separate marsh and mangrove, and distinguish between beach and unvegetated barrier flat habitats. To ensure comparability between this effort and previous BICM map products, we have crosswalked the detailed classes to general habitat classes previously used by older BICM datasets available for 1996/98, 2002, 2004, and 2005.
Table 1 shows the description of the detailed habitat classes along with the detailed to general class crosswalk.
For more information on barrier island mapping methodology, please see Enwright and others (2019) or the metadata for the BICM products produced by the U.S. Geological Survey, Wetland and Aquatic Research Center (https://www.sciencebase.gov/catalog/item/5a32ebe1e4b08e6a89d886b4).
Table 1. BICM detailed and general classification schemes [--, not applicable].
Detailed class | Description | Description source | General class |
---|---|---|---|
Beach | Beach habitat includes supratidal bare or sparsely vegetated areas (that is, above the extreme high water springs tide level) located along coastlines with high wave energy (that is, Gulf-facing shorelines). Vegetation cover is generally less than 30 percent. Beach transitions into dunes, meadow, or unvegetated flat where overwash is evident. Beach includes the backshore zone of a beach. | Modified from Cowardin et al., 1979 | Beach |
Unvegetated dune | Dunes are supratidal features (that is, above the extreme high water springs tide level) developed via Aeolian processes. Dunes are often located above typical storm water levels and have a well-defined relative elevation (that is, upper slope or ridge). Unvegetated dune includes dune habitat that has less than 10 percent vegetation cover. | Modified from Psuty, 1989 | Bare land |
Vegetated dune | Dunes are supratidal features (that is, above the extreme high water springs tide level) developed via Aeolian processes. Dunes are often located above typical storm water levels and have a well-defined relative elevation (that is, upper slope or ridge). Vegetated dune includes dune habitat that has greater than 10 percent vegetation cover. | Modified from Psuty, 1989 | Barrier vegetation |
Unvegetated flat | Unvegetated barrier flat includes flat or gently sloping supratidal unvegetated or sparsely vegetated areas (that is, areas located above extreme high water springs tide level) that are located on the backslope of dunes, unvegetated washover fans, and along low-energy shorelines. Vegetation coverage should be generally less than 30 percent. | Modified from Leatherman, 1979 | Beach |
Meadow | Meadow includes supratidal areas (that is, above the extreme high water springs tide level) with sparse to dense herbaceous vegetation located in areas leading up to dunes and on the barrier flat (that is, backslope of dunes and supratidal, back-barrier habitat). Vegetation coverage should generally be greater than 30 percent. Classification of meadow habitat is restricted by geomorphic settings. Meadow is reserved for areas located on barrier flats of barrier islands, backslopes of dunes, transitional vegetated areas in dune/beach habitats. | Modified from Lucas and Carter, 2010 | Barrier vegetation |
Intertidal | Intertidal includes bare or sparsely vegetated areas located between the extreme low water springs and extreme high water springs tide levels. Vegetation cover should generally be less than 30 percent. Intertidal includes the foreshore zone of a beach. | Cowardin et al., 1979 | Intertidal |
Estuarine emergent marsh | Estuarine emergent marsh includes intertidal saline emergent marsh (that is, located above extreme low water springs and below extreme high water springs tide levels) and supratidal brackish emergent marsh. Vegetation cover should be generally 30 percent or greater cover by erect, rooted, herbaceous hydrophytes. Note, supratidal emergent vegetation that is located on the backslopes of dunes will be classified as meadow. | Cowardin et al., 1979 | Estuarine vegetated wetland |
Mangrove | Mangrove habitat includes areas with black mangrove (Avicennia germinans). Mangrove vegetation coverage should generally be greater than 30 percent. | -- | Estuarine vegetated wetland |
Bare land | Bare land includes bare or sparsely vegetated areas that are often located above typical storm water levels and are associated with unvegetated spoil or inland ridges. Vegetation cover should generally be less than 30 percent. | Modified from Fearnley et al., 2009 | Bare land |
Grassland | Grassland includes upland areas covered by herbaceous vegetation often located above typical storm water levels and are associated with inland spoil banks with herbaceous vegetation, freshwater emergent marsh, and upland areas along the mainland in the Chenier Plain BICM regions. | Modified from Homer et al., 2015 | Barrier vegetation |
Scrub/shrub | Scrub/shrub includes areas where woody vegetation height is greater than about 0.5 meters, but less than 6 meters. Woody vegetation coverage should generally be greater than 30 percent. | Cowardin et al., 1979 | Barrier vegetation |
Forest | Forest includes areas where woody vegetation height is greater than 6 meters. Woody vegetation coverage should generally be greater than 30 percent. | Cowardin et al., 1979 | Barrier vegetation |
Shoreline protection | Shoreline protection includes any material used to protect shorelines against erosion (for example, breakwater, groins, and jetties). | Fearnley et al., 2009 | Rip-rap |
Developed | Developed includes areas dominated by constructed materials (that is, transportation infrastructure, and residential and commercial areas) and open developed areas. | Modified from Homer et al., 2015 | Structure |
Water | Water includes areas of open water with generally less than 30 percent cover of vegetation. | Modified from Cowardin et al., 1979 | Water |
Barrier islands are very dynamic environments due to their position at the land-sea interface. Thus, land managers require information on how habitats on these islands are changing over time. In response, the BICM program has produced spatially explicit habitat change products that depict and summarize habitat change between 2008 and 2015/2016 per BICM reach. The results from these analyses were summarized in two habitat change products. The first product depicts change in land and water coverage and the second product highlights changes based on inundation zones.
BICM detailed habitat classes were used to develop generalized habitat bins for these change analyses (Table 1). Next, change was determined between/amongst these bins (that is, change classes; Table 2).
For more information on the methodology used for the BICM habitat change products, please see the metadata for the BICM products produced by the U.S. Geological Survey, Wetland and Aquatic Research Center (https://www.sciencebase.gov/catalog/item/5a32ebe1e4b08e6a89d886b4).
Table 1. BICM change products bins with associated BICM detailed habitat classes.
BICM habitat change product | Generalized classes for change | BICM detailed classes |
---|---|---|
Land/Water | Land | Bare land, Beach, Developed, Estuarine emergent marsh, Forested, Grassland, Mangrove, Scrub/shrub, Shoreline protection, Unvegetated dune, Unvegetated flat, Vegetated dune |
Water | Water, Intertidal | |
Inundation zone-based | Water | Water |
Intertidal-unvegetated | Intertidal | |
Intertidal-vegetated | Estuarine emergent marsh, Mangrove | |
Supratidal | Bare land, Beach, Forest, Grassland, Meadow, Scrub/shrub, Unvegetated dune, Unvegetated flat, Vegetated dune | |
Developed/shoreline protection | Developed and Shoreline protection |
Table 2. BICM change classes for each BICM habitat change product.
BICM habitat change product | Change classes |
---|---|
Land/Water |
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Inundation zone-based |
|