Wetlands Characteristics and Boundaries (1995) / Chapter Skim
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APPENDIXES
APPENDIXES
Pages 253-296
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From page 253... ...
Histosols are organic soils, formed almost exclusively in wetlands, whereas the other orders are mineral soils. The second level in the taxonomic hierarchy is "suborder." Many wetland soils are in Aquic suborders, and they have an aquic moisture regime.
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From page 254... ...
might or might not be a "hydric soil" (SCS, 1991~. AQUIC CONDITIONS The term aquic conditions was introduced in 1992 as a result of recommendations submitted to the Soil Conservation Service by the International Committee on Aquic Moisture Regime (ICOMAQj, which was established in 1982 (Soil Survey Staff, 1994~.
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From page 255... ...
is from "Keys to Soil Taxonomy" (Soil Survey Staff, 1994, p.
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From page 256... ...
Soil slope, texture, structure, and other characteristics also are useful for evaluating soil drainage conditions. There are seven soil drainage classes, ranging from "very poorly drained" to "excessively drained." The three wettest categories, as defined in the Soil Survey Manual (Soil Survey Staff, 1993, pp.
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From page 257... ...
The occurrence of internal free water commonly is shallow to moderately deep and transitory to permanent. Soil Inundation Inundation is the condition of soil when an area is covered by liquid free water (Soil Survey Staff, 1993~.
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From page 258... ...
Figure B 1.1 shows the location of the Kirkham wetlands, and the area can be used to illustrate many of the challenges for characterizing and delineating forested wetlands in Maryland and adjoining states.
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From page 259... ...
The indicator status of the plant community can change when the overstory is removed. For example, removal of trees could reduce depletion of ground
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From page 260... ...
As shown by Figure B 1.3, there is a strong seasonal variation in the water table at the Kirkham site. The highest water tables are found in late winter or spring.
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From page 262... ...
USACE delineated the Kirkham site according to the guidelines in the 1987 manual (Figure B 1.2~. Hydric soils extended over the entire site and beyond the margin of wetland vegetation.
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From page 263... ...
Therefore, it is possible that all or part of the Kirkham wetlands could be incrementally altered under Nationwide Permit 26, regardless of the delineation boundaries. CASE HISTORY 2 Yazoo National Wildlife Refuge Lower Mississippi Valley Relict Soils and Altered Hydrology Wetlands occupied by bottomland hardwood forest account for many millions of acres in the southeastern United States (Clark and Benforado, 1981~.
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From page 264... ...
of wetland in the district. Studies of the Steele Bayou wetlands of the Yazoo National Wildlife Refuge have provided information on some of the issues that arise in the delineation of
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From page 265... ...
From the field setting, it is clear that the Dundee soil of the ridge is not inundated under the current hydrologic regime. The Steele Bayou site thus indicates the problem of relict soils: Hydric soils that formed under wetland conditions continue to show hydric characteristics after the hydrologic conditions change.
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From page 266... ...
CL ' ( ' cJ~ on ._ ~ ad /~ Eagle six -wake ~ FIGURE B2.2 General location of the Steele Bayou site.
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From page 267... ...
~, ~4 ~ZONE Vl - - - - 2 ~ZONE IV _ _ _ - - - _ FIGURE B2.4 Map of the Steele Bayou site showing zonation.
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From page 268... ...
::::::::~::::::~::~::::~::::~::::~::: :::~:~::~:::~::::~::::::::~:~:::::::~::: :::::::::::::::::::::::::::::::: ::::~::~::~:::~:::~:::::::::::::::::: .~ . ~A - - A ~ ~~:v~ ~ : : l ~ ~ ~ - B ~ ~ S N J M AM J A O J F MA M J A O JF A M J 82 83 84 85 FIGURE B2.5 Oxygen, redox potential, and water table level in zones VI and IV of the Steele Bayou wetlands.
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From page 269... ...
~ 2 .d ~ . ~ Redox potential Growing season _ - -.-.
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From page 270... ...
analyzed the association between vascular plant species and hydrologic regimes at 17 sites, including the Steele Bayou site, in the southeastern United States. Multivariate statistical analysis showed a strong association between community composition and hydrologic regime.
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From page 271... ...
The Steele Bayou site thus provides a good example of the low sensitivity of woody vegetation to hydrologic change over the short term, even though community composition will change to reflect hydrology over the long term. Until the hydrology changed, delineation of the wetland boundary at the Steele Bayou site was relatively straightforward on the basis of plant community composition and surface indicators of hydrology.
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From page 272... ...
The Verde River channel in the vicinity of Dead Horse Ranch State Park contains depressions that were created by erosion at high flow. These depressions are typically a few feet to tens of feet in
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From page 273... ...
During the growing season, which extends from March through October in the lower reaches of the Verde River, these sites are likely to be dry. They lack extensive woody vegetation, although some support populations of the Goodding willow (Salix gooddingii)
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From page 274... ...
Surveys at the Dead Horse Ranch State Park site along the Verde River show 162 species of birds, including several listed as endangered and threatened species by the federal and state government; the avifauna includes shore birds, waterfowl, and tropical migrants. The channel and floodplain depressions of the Verde River can be classified as wetland only by liberal use of the guidelines now in use for identification of wetlands.
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From page 275... ...
Toward the end of the dry season, the water table of hydric pine flatwoods can be as much as 3 It (0.9 m) below the surface.
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From page 276... ...
(Beever and Dryden, 1992) , and the number of species throughout the hydric pine flatwoods of southwest Florida is high: There are 992 plant species, including 98 that are federally listed (Beever and Beever, 19949.
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From page 277... ...
The delineation of boundaries for hydric pine flatwood is difficult. The interior of the hydric zone shows many diagnostic features of wetland status, including dried algal mats, remains of aquatic invertebrates, hydrophytic vegetation, and hydric soils.
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From page 278... ...
~o ~/o soutbFloddal943-1970. Sou~Flodda Environ.
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From page 279... ...
Ground water plays an important role in sustaining the prairie potholes. The potholes can be divided roughly into three hydrologic categories: recharge, throughflow, and discharge.
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Invertebrate fauna of the prairie potholes is diverse and abundant. It includes such taxa as the phantom midge (Chaoborus)
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From page 281... ...
Less obvious but equally important is the role of potholes in ground water recharge and hydrologic buffering (Winter, 1989~. Prairie potholes that are farmed in dry years qualify as farmed wetlands under the Food Security Act of 1985.
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From page 282... ...
Thus, even with hydrologic records, it is difficult to compute reliably the recurrence, frequency, duration, and depth of inundation for individual potholes. Because of the high variability of vegetation, aquatic life, and hydrology over the short term, hydric soils are a particularly important indicator of wetland status in the prairie pothole region.
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From page 283... ...
283 FIGURE BS.3 Long-term hydrologic record from the prairie pothole region reconstructed from historical records and tree ring data.
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From page 284... ...
aquic soil-soil that currently experiences continuous or periodic saturation and reduction. Presence indicated by redoximorphic features and verified by measuring saturation and reduction, except in artificially drained soils.
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From page 285... ...
An order of the USDA soil taxonomy. epipedon diagnostic horizon formed at the soil surface, used in the classifica
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From page 286... ...
An order of the USDA soil taxonomy. hydric soil- soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part (1991 National Technical Committee on Hydric Soils definition)
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From page 287... ...
An order of the USDA soil taxonomy. monotypic-being the only representative of its group, or more commonly, having only one type, e.g., a genus or plant community consisting of a single species.
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From page 288... ...
An order of the USDA soil taxonomy. paludification landscape phenomenon of the accumulation of organic matter on a mineral soil thus forming a Histosol.
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From page 289... ...
restoration return of an ecosystem to a close approximation of its condition prior to disturbance. riparian ecosystem ecosystem that has a high water table because of its proximity to an aquatic ecosystem or to subsurface water.
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From page 290... ...
. tidal subsidy-augmentation or support of water tables by tidal fluctuations; the way in which nutrients are added and toxic materials removed from areas of greater tidal energy.
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From page 291... ...
Professor Lewis has served on the National Research Council Committee on Irrigation-Induced Water Quality Problems and is currently Chair of the NRC's Glen Canyon Environmental Studies Committee. He is also a member of the NRC's Water Science and Technology Board.
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From page 292... ...
lIer research includes plant ecology of freshwater ecosystems; application of ecological knowledge to environmental assessment, regulation and management; response of wetland plants and communities to changes in hydrology and nutrient loading; and influence of plant species on wetland ecosystem processes.
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From page 293... ...
Her research interests include wetland soils, biogeochemistry, and mapping; effects of land/water interactions on surface water quantity and quality, spatial and temporal variability of wetland processes; and geographic information systems.
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His research interests include physicochemical properties of and reactions in soils, particularly wetland soils.
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Currently, he is the William Neal Reynolds Professor at NC State. His expertise is in agricultural drainage and related water management for poorly drained soils; hydrology of low relief and high water table watersheds.
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