Kentula, U. Environmental Protection Agency The benefits of restoration of degraded or destroyed wetlands and creation of new wetlands has only recently been recognized. As the population has expanded across the Nation during the past few centuries, wetlands have been drained and altered to accommodate human needs. These changes to wetlands have directly, or indirectly, brought about changes in the migratory patterns of birds, local climate, and the makeup of plant and animal populations. In the past, people used wetland plants and animals for shelter and food.
The first edition U. Elements of wwtlands hydrology that are important to maintaining a wetland are inflows and outflows of ground water and surface water, the resulting water levels, and the timing and duration of soil saturation Twin valley homes virginia flooding. Rejuvenstion is because the slope determines how far the substrate soil or rock material that forms the surface of the basin will be from water and how much of Rejuvenation of florida wetlands substrate has the necessary conditions of wetness for specific plant species Hollands, Plant communities vlorida in project wetlands will fare better if they closely resemble communities in similar, local Rejuvenation of florida wetlands. Functions in a group of restored wetlands can be expected to increase gradually with time to a point of maturity at which time the level of function has stabilized. Environmental Protection Agency The benefits of restoration of degraded or destroyed wetlands and creation of new wetlands has only recently been recognized. Wenzel, T.
Nudist carrie. EVALUATION OF SUCCESS
In the Southeastern Wetlwnds. Maintain documentation to verify the implementation and maintenance of the non-regulatory and incentive-based BMPs as outlined in 5I The forestry community, with general support of the Water Management Districts WMDswhich regulate agricultural and silvicultural fill and dredge activities, has interpreted these exemptions to mean that harvest, site preparation, and planting are exempt from regulation. In developing silviculture Best Management Practices BMPs Rejuvenatio, States have identified specific forestry practices that will help protect water quality. Decades of research has shown mosquito breeding can be managed with less undesirable consequences by reconnecting impoundments to adjacent waterways via culverts and flooding the impoundments only during September through Wetland, the breeding Rejuvenation of florida wetlands for mosquitos. Dragline ditching reduced the mosquito populations in coastal wetlands, but it also created unintended alterations and reductions in ecosystem services. Mosquito impoundments interrupt mosquito breeding by creating isolated wetlands that can be flooded with water from wells or the wetlanda waterways. Contact information for the participating organizations: Institute of Food and Agricultural Sciences Cooperative Extension Rejuvenation of florida wetlands USDA Natural Resource Conservation Service Application of Silviculture BMPs to Mechanical Site Preparation Activities As you may know, forested wetlands exhibit a wide range of water regimes, soils, and vegetation types Rejuvenation of florida wetlands provide many functions and values visit our bottomland forest ecosystems of Florida section to learn more. They were flprida used to create approximately 40, acres of impoundments used for mosquito control. Some of these important functions are outlined below:. Riverine Bottomland Hardwood Wetlands These are seasonally flooded or wetter bottomland hardwood wetlands on the floodplains of river systems. Other benefits include larger numbers of native wetland plants, such Ns model railroad black mangroves; less invasive vegetation; improved shelter wetlahds juvenile fish in the remaining shallow water; no increase in mosquito breeding. As a result of this successful pilot, Volusia County bought two marsh excavators — earth-moving machines modified with pontoons to transform them into amphibious machines.
The wetland has performed better than design expectations, but phosphorus removal effectiveness experienced some seasonal declines beginning with the winter of
- It wasn't until the s, after more than half of the original wetlands in the landlocked 48 states had already been drained, that protective legislation emerged.
- Coastal wetlands are among the most biologically productive natural systems on Earth.
- Florida has the most aggressive state-level program of the Gulf Coast States.
- The Florida Department of Environmental Protection has the responsibility to perform Formal Wetland Delineations, provide training in wetland delineation and classification to regulatory agencies, provide technical assistance to other programs of the department, and ensure the consistent statewide use of the Florida Unified Wetland Delineation Methodology Chapter , F.
- Wetlands is a term used to describe transitional lands between terrestrial upland and aquatic bottomland systems where the water table is usually at or near the surface, or the land is covered by shallow water.
The wetland has performed better than design expectations, but phosphorus removal effectiveness experienced some seasonal declines beginning with the winter of Subsequent studies indicated that the OEW treatment capacity was hindered by inefficient phosphorus removal in the upstream cells of one of three flow trains. Therefore, rejuvenating management activities were initiated on these cells in The management included the removal of plants and organic top sediments, site grading in the interior of the cells, construction of baffles and islands, and re-vegetation.
This study evaluates the improvement in hydraulic and phosphorus removal performance realized from the wetland modifications. Improvement of hydraulic performance was evaluated based on tracer tests, and improvement of phosphorus removal performance was evaluated based on episodic spatially distributed water samples as well as model prediction.
The results showed that both the hydraulic efficiency and the phosphorus removal effectiveness of the rejuvenated wetland were significantly increased.
However, the wetland has likely re-entered a start-up phase and long-term observation will be necessary to determine eventual steady-state conditions.
DOI: Jawitz; John R. White; Christopher J. Martinez; Mark D.
The water table is often near the surface. For the wetland types identified below, it is most effective to evaluate proposals for site preparation and associated environmental effects on a case-by-case basis as part of the individual permitting process. From this point, the permitting processes proceed independently. Wetland habitats are transitional regions between land and sea that provide an array of ecosystem functions. To understand why the district and many partners began restoring thousands of acres of coastal wetlands, one must first understand how they came to be impacted. These are seasonally flooded or wetter bottomland hardwood wetlands on the floodplains of river systems. Formal Determinations.
Rejuvenation of florida wetlands. Submerged Lands and Environmental Resources Coordination Program Quick Links
Kentula, U. Environmental Protection Agency The benefits of restoration of degraded or destroyed wetlands and creation of new wetlands has only recently been recognized.
As the population has expanded across the Nation during the past few centuries, wetlands have been drained and altered to accommodate human needs.
These changes to wetlands have directly, or indirectly, brought about changes in the migratory patterns of birds, local climate, and the makeup of plant and animal populations. In the past, people used wetland plants and animals for shelter and food.
More recently, people have become more aware of other benefits that wetlands provide water-quality improvement, flood attenuation, esthetics, and recreational opportunities. Now, it is recognized that numerous losses are incurred when a wetland is damaged or destroyed.
Restoration and creation can help maintain the benefits of wetlands and their surrounding ecosystems, and at the same time accommodate the human need for development.
Wetland restoration rehabilitates a degraded wetland or reestablishes a wetland that has been destroyed. Restoration takes place on land that has been, or still is, a wetland.
A term commonly associated with restoration is "enhanced. For example, enhancing a site to increase its use by a particular species of bird commonly limits its use as habitat for other species. Wetland creation is the construction of a wetland on a site that never was a wetland. This can be done only on a site where conditions exist that can produce and sustain a wetland. Consequently, creation is more difficult than restoration. A term commonly associated with wetland creation is "constructed.
As used in this article, "project wetland" refers to restored or created wetlands. For a more complete discussion of the meaning of these terms and others associated with restoration and creation, see Lewis, Click on image for a larger version, 80K.
Wetland alterations have brought about changes in the migratory patterns of birds, local climate, and make up of plant and animal populations. The relative merits of destroying the function of an existing wetland, or other ecosystem, in exchange for another wetland function involves the consideration of numerous questions such as: 1 Which is more important, the existing or the replacement function?
Questions of this type always arise during planning for wetland restoration and creation. A well-documented example of a physical limitation associated with restoring a wetland can be seen along the shoreline of the Salmon River Estuary, Oreg. Frenkel and Morlan, , In the past, many high marsh wetlands along the Pacific coast were diked to remove them from tidal action. After the area was diked, the wetlands dried up and the land was used for pasture.
In , in an effort to restore the Salmon River Estuary to its original condition, two dikes were removed to allow the original wetlands to reestablish themselves. However, after 10 years, the resulting wetlands fig. The land behind the dikes had subsided over time, and the restored wetlands were more typical of wetlands at lower elevations nearer the estuary low marsh.
Although the wetlands continue to evolve as sediments are trapped and deposited by the vegetation thus raising the elevation , it might take another 50 years for the restored wetlands to become similar again to the original high marsh Frenkel and Morlan, The time required and the ability to develop a fully functional soil system in project wetlands may be major determinants of the eventual acceptance or rejection of restoration and creation as management options.
It is difficult to make a definitive statement about the ability to replace wetland functions. Goals for restoration and creation projects seldom are stated and information on the existing functions of the wetlands seldom are documented.
This is due, in part, to the difficulty and expense of quantifying wetland functions. Also, responsible monitoring during construction and after completion of the project wetland is uncommon. Most information available on project wetlands is in the form of qualitative case studies. Restoration and creation can help maintain the benefits of wetlands and accommodate the human need for development.
Although there is no "cookbook" for restoring or creating wetlands, documents describing general approaches to restoration and creation and the conditions conducive to project success are available Garbisch, ; Marble, ; Pacific Estuarine Research Laboratory, ; Hammer, ; Maynord and others, Elements common to wetland project design are site-selection criteria, hydrologic analysis, water source and quality, substrate augmentation and handling, plant material selection and handling, buffer zones placement, and long-term management.
A brief overview of each element is presented here in a sequence similar to that followed in project planning. Site selection. A wetland's structure, function, and ability to persist over time are greatly influenced by its location. Wetlands in settings with limited human influence can differ greatly in structure and function from wetlands in settings dominated by human activities.
Therefore, the present and projected land uses of the surrounding area are a consideration when selecting the site. The characteristics of existing wetlands, in the same general area, or in an area with similar land uses, can be used as models for what might be expected of the project wetland. Benefits that extend beyond the wetland itself can be derived from the placement of a wetland if care is taken in site selection. For example, restoration of riverbank wetlands between agricultural land and a stream can improve downstream water quality Olson, Hydrologic analysis.
Elements of site hydrology that are important to maintaining a wetland are inflows and outflows of ground water and surface water, the resulting water levels, and the timing and duration of soil saturation or flooding. One factor influencing hydrology is the configuration of the basin depression containing the wetland. The position of the basin surface relative to the water table influences the degree of soil saturation and flooding. To ensure that standing water is present year round, many project wetlands are excavated so that the deepest part of the basin is below the lowest anticipated water level.
The slope of the basin banks determines how much of the site will be vegetated and by what kinds of plants fig. This is because the slope determines how far the substrate soil or rock material that forms the surface of the basin will be from water and how much of the substrate has the necessary conditions of wetness for specific plant species Hollands, The ability to maintain the desired plant community, therefore, is ultimately dependent on the hydrology of the site.
In a properly constructed freshwater marsh, the lowest point of the wetland will be inundated to a depth and for a period long enough that emergent vegetation can persist, but not so long as to destroy the plants.
Benefits can extend beyond the wetland if care is taken in site selection. Click on image for a larger version, 59K. Substrate augmentation and handling. Soil Conservation Service, fig.
Most of the chemical reactions in wetlands take place in the soils, where most chemicals are stored Mitsch and Gosselink, The soils of project wetlands are receiving increased attention as studies link substrate characteristics to ecological function.
Although a created wetland may be structurally similar to a natural wetland, its hydrology may differ greatly from that of the natural wetland if the permeability of the substrates differ O'Brien, In addition to differences in permeability, soils in project wetlands commonly have a smaller amount of organic matter than soils in similar natural wetlands.
Because organic matter in soils stores nutrients that are critical to plant growth Pacific Estuarine Research Laboratory, , the smaller amounts of organic matter in soils of project wetlands may limit plant growth Langis and others, Augmenting, or mulching, the substrate of project wetlands with materials from a "donor" wetland can increase soil organic matter and provide a source of needed plant species, microbes, and invertebrates. Mulching makes the substrate more conducive to rapid revegetation by reducing the evaporation of pore water, runoff, soil loss and erosion, and surface compaction and crusting Thornburg, Mulching also can cause problems such as the introduction of unwanted plant species.
Plant material selection and handling. Because of the unique and stressful conditions that develop in wetlands, varying from long periods of flooding to periodic drying, plants and animals found there have developed distinctive mechanisms to deal with these stresses and conditions. It is important to recognize the constraints of this unique environment when planning a project wetland.
Plant communities established in project wetlands will fare better if they closely resemble communities in similar, local wetlands.
To increase the likelihood of successful colonization, Garbisch suggests that project managers: Select herbaceous species that rapidly stabilize the substrate and that have potential value for fish and wildlife Select species that are adaptable to a broad range of water depths. A survey of vegetation at wetlands of the type being created or restored can identify the conditions of "wetness" needed by species Avoid choosing only those species that are foraged by wildlife expected to use the site-muskrats and geese have been known to denude sites Avoid committing significant areas of the site to species that have questionable potential for successful establishment In addition, Stark suggests the selection of "low maintenance" vegetation.
Hydrologic conditions probably are the most important determinants of wetland types and processes. Click on image for a larger version, 74K. Chemicals from the surrounding landscape can overwhelm a wetland's ability to improve water quality. This is true for many reasons-lack of clearly stated objectives, lack of long-term monitoring Kusler and Kentula, b , and the subjective point of view of the definer Roberts, The vast majority of project wetlands are ecologically young years of age or less.
The lack of information on ecologically mature projects limits the ability to predict whether or not the functions of project wetlands can replace the functions of natural wetlands. Nevertheless, the results of ongoing research and good professional judgment can be used to provide insight into the selection of projects that have a high probability of success. Various attempts have been made to define success criteria for wetland projects.
The earliest criteria assumed that if conditions were correct for the establishment of wetland vegetation, then other ecological functions would either be present or develop over time. Now, it is known that a site "green" with vegetation does not necessarily mean success, and the standards by which projects are judged are more likely to be tied to wetland functions.
The Wetlands Research Program of the U. Environmental Protection Agency EPA is developing an approach to establish quantitative performance criteria for project wetlands. In this approach, groups of natural wetlands serve as reference sites against which project wetlands are judged.
For example, Zedler uses reference data from natural marshes being used by clapper rails an indigenous bird species to define criteria that can be used to judge the suitability of restored and created habitat for the birds. Older project wetlands also are used as reference sites against which to judge newer project wetlands, both to verify that development is as expected and to identify developmental patterns that may have resulted from changes in project design Kentula and others, This approach is designed to produce results that are regionally applicable to wetland protection and management.
One tool for comparing the characteristics of project wetlands with similar, naturally occurring wetlands is a performance curve fig. Functions in a group of restored wetlands can be expected to increase gradually with time to a point of maturity at which time the level of function has stabilized. The mean level of function in mature project wetlands is generally less than that for natural wetlands. Rate and time of maturation and functional level at maturity will differ from project to project, depending on the type of wetland being restored.
The curve provides information on when to monitor, how restored wetlands typically develop, and when project goals have been met. Changes in the characteristics of project wetlands can be expected in response to the maturation process, but also in response to changes in the environment. Information on the development of project wetlands and similar natural wetlands helps managers determine whether an observed change is typical for a particular year or stage of development.
Click on image for a larger version, 98K. Over time, successful project wetlands can be expected to become similar to comparable natural wetlands.