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Wetlands by Broad Land Cover/Use, by State, 1992

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Description

This pie map contains a pie chart for each state and the nation. The pie slices reflect acres of wetlands in various land cover/use categories as a percent of the total area of wetlands. The size of the pies is proportional to the amount of wetlands in the state (scaled between New Mexico with 39,400 acres at .1 inch and Minnesota with 10,865,300 acres at .7 inch). Wetlands data are not collected on Federal land. There were 111,307,700 acres of Wetlands in 1992.

Cautions for this Product:
Wetlands do not include deepwater habitats. The 1% of wetlands on developed land (urban areas and rural transportation land) are not incorporated into the pies. The pies also do not include any wetlands located on Federal land. The national pie is not proportional to the state pies.



Sources

Source: National Resources Inventory, 1997
Distributor: USDA-NRCS-RIAD
Reliability:
NRI sample data are generally reliable at the 95% confidence interval for state and certain broad substate area analyses. Generally, analyses that aggregate data points by smaller geographic areas and/or more specific criteria result in fewer data points for each aggregation and therefore less reliable estimates. NRI maps reflect national patterns rather than site- specific information.


Layers

Aggregate Layer: State
Other Layers Displayed:


Definitions

Cropland:
A Land cover/use category that includes areas used for the production of adapted crops for harvest. Two subcategories of cropland are recognized: cultivated and noncultivated. Cultivated cropland comprises land in row crops or close-grown crops and also other cultivated cropland, for example, hayland or pastureland that is in a rotation with row or close-grown crops. Noncultivated cropland includes permanent hayland and horticultural cropland. [NRI-97]

Deepwater habitat:
Any open water area in which the mean water depth exceeds 6.6 feet in nontidal areas or at mean low water in freshwater tidal areas, or is covered by water during extreme low water at spring tides in salt and brackish tidal areas, or covers the deepest emerging vegetation, whichever is deeper [USFWS]

Forest land:
A Land Cover/Use that is at least 10 percent stocked by single stemmed forest trees of any size which will be at least 4 meters (13 feet) tall at maturity. When viewed vertically, canopy cover is 25 percent or greater. Also included are areas bearing evidence of natural regeneration of tree cover (cutover forest or abandoned farmland) and not currently developed for nonforest use. For classification as forest land, an area must be at least one acre and 100 feet wide. [NRI-97]

Marshland:
A sub-category of the Land Cover/Use category Other Rural Land described as a nonforested area of land partially or intermittently covered with water usually characterized by the presence of monocotyledons, such as sedges and rushes. These areas are usually in a wetland class and are not placed in another NRI land cover/use category such as rangeland or pastureland. [NRI- 97]

Other rural land:
A Land cover/use category that includes farmsteads and other farm structures, field windbreaks, barren land, and marshland. [Revised 1992 NRI Summary Report, omitting CRP land.]

Pastureland and Native Pasture:
A Land Cover/Use category of land managed primarily for the production of introduced or native forage plants for livestock grazing. Pastureland may consist of a single species in a pure stand, a grass mixture or a grass-legume mixture. Management usually consists of cultural treatments-fertilization, weed control, reseeding, or renovation and control of grazing. (For the NRI, includes land that has a vegetative cover of grasses, legumes, and/or forbs, regardless of whether or not it is being grazed by livestock.) [NRI-97]

Rangeland:
A Land cover/use category on which the climax or potential plant cover is composed principally of native grasses, grasslike plants, forbs or shrubs suitable for grazing and browsing, and introduced forage species that are managed like rangeland. This would include areas where introduced hardy and persistent grasses, such as crested wheatgrass, are planted and such practices as deferred grazing, burning, chaining, and rotational grazing are used, with little or no chemicals or fertilizer being applied. Grasslands, savannas, many wetlands, some deserts, and tundra are considered to be rangeland. Certain communities of low forbs and shrubs, such as mesquite, chaparral, mountain shrub, and pinyon-juniper, are also included as rangeland. [NRI-97]

Water body:
A type of (permanent open) water area which includes ponds, lakes, reservoirs, bays or gulfs, and estuaries. There are 3 size categories: (1) less than 2 acres; (ii) 2-40 acres; and (iii) at least 40 acres. [NRI-97]

Wetland:
Areas that have a predominance of hydric soils and that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and under normal circumstances do support, a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions. [NFSAM]

Wetland System:
Complex of wetland habitats that share the influence of similar hydrologic, geomorphologic, chemical, or biological factors. [U.S. FWS]


Product Information

Product ID: 5025
Production Date: 5/4/01
Product Type: Map


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