What is wetlands ecology

Wetlands, which are fluctuating ecosystems inherently difficult to categorize, are often found at the intersection of terrestrial habitat and aquatic habitat and usually include elements of both systems. Many wetlands are unique to a certain degree, as their individual characteristics are determined by a combination of factors such as climate, soils, hydrology, and vegetation.

Watersheds and water bodies associated with wetlands control the quantity and quality of water reaching wetlands, and thus affect wetland functions. For this reason, regulation of activities within a wetland boundary is not always sufficient to maintain all wetland functions. Not all functions occur in all wetlands, nor are wetlands structurally uniform, but classification of wetlands into groups that share hydrogeomorphic and other properties clarifies similarities and differences in function.

Wetlands often occupy only a small proportion of the watershed in which they lie, yet they often maintain exceptional biodiversity and process a large proportion of the dissolved and suspended materials leaving uplands, which typically occupy greater areas. When wetlands are removed, their collective functions are likely to decrease faster than the rate of reduction in surface area.

More intensive and regionally diverse studies of the following basic wetland phenomena should be undertaken in support of a stronger foundation for identification, delineation, and functional protection of wetlands:. But what does it signify? In , proposed changes in the legal definities of wetlands stirred controversy and focused attention on the scientific and economic aspects of their management.

This volume explores how to define wetlands. The committee—whose members were drawn from academia, government, business, and the environmental community—builds a rational, scientific basis for delineating wetlands in the landscape and offers recommendations for further action. Wetlands also discusses the diverse hydrological and ecological functions of wetlands, and makes recommendations concerning so-called controversial areas such as permafrost wetlands, riparian ecosystems, irregularly flooded sites, and agricultural wetlands.

It presents criteria for identifying wetlands and explores the problems of applying those criteria when there are seasonal changes in water levels. This comprehensive and practical volume will be of interest to environmental scientists and advocates, hydrologists, policymakers, regulators, faculty, researchers, and students of environmental studies.

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Get This Book. Visit NAP. Looking for other ways to read this? No thanks. Wetlands: Characteristics and Boundaries. Page 21 Share Cite. Page 22 Share Cite. Hydrology as a Driving Force. Page 23 Share Cite. Page 24 Share Cite. Page 25 Share Cite. Organic Matter. Page 26 Share Cite. Page 27 Share Cite. Page 28 Share Cite. Page 29 Share Cite. Page 30 Share Cite.

Page 31 Share Cite. Page 32 Share Cite. Page 33 Share Cite. Page 34 Share Cite. Page 35 Share Cite. Page 36 Share Cite. Landscape Perspective. Page 37 Share Cite. Relationship to Biodiversity. Page 38 Share Cite. Removal of Nutrients and Sediments. Page 39 Share Cite. Eggs hatch days; adults feed on water Lethocerus americanus Adult and nymph stage Notonecta undulata Entire life cycle Notonecta kirbyi Entire life cycle Hydrophilus spp.

All but a few weeks Dineutus spp. All but pupal and part of adult stages Thermonectes marmoratus All but pupal stage Chrysomela lapponica None Labidomera clivicollis None Xylotrechus insgnis None Brachinus spp. None Chalenius seiceus None Donacia spp.

Larval stage Corydalus cornutus Two or three years Acroneuria californica One year or more Grammotaulius bettenii All but short adult stage Nannothemis bella Nymphs develop slowly Libellula luctuosa Egg to nymph Boyeria vinosa Egg to nymph Anax junius Overwinter Argia spp.

Egg through naiad Pachydiplax longipennis Egg through nymph Libellula pulchella Egg through nymph Celithemis elisa Nymphs overwinter Sympetrum illotum Nymphs overwinter Lestes congener Eggs and nymphs overwinter until July Tipula spp. None Agathos comstocki All but adult Baetis spp. Eggs hatch weeks; nymphs Culex pipiens Eggs hatch days; larvae pupate weeks Chlorion cyaneum none Tabanus americanus Two years Simulium spp. Page 40 Share Cite. Wetlands as Hydrologic Features of Watersheds. Page 41 Share Cite.

Page 42 Share Cite. Page 20 Share Cite. Login or Register to save! Stay Connected! Distribution and Hydrology. Widespread; seasonal to permanent flooding. Intertidal zones; semidiurnal to fortnightly flooding. Salt-tolerant grasses and rushes, killifish, crabs, clams, snails. Associated with mineral-rich water; permanently saturated by flowing water. Sphagnum moss, shrubs, trees, desmids. Seasonal flooding; annual dry periods.

Presence of floodplain along river corridor. Coastal non-floodplain rock lake. Coastal non-floodplain sand lake — Window. Coastal non-floodplain sand lake—Perched. Coastal non-floodplain soil lake. Palustrine Arid and semi-arid grass, sedge and herb swamp.

Arid and semi-arid lignum swamp. Arid and semi-arid tree swamp. Arid and semi-arid saline swamp. Coastal and subcoastal floodplain grass, sedge, herb swamp. Coastal and subcoastal floodplain tree swamp. Coastal and subcoastal floodplain wet heath swamp. Coastal and subcoastal saline swamp. Coastal and subcoastal tree swamp—Palm. Coastal and subcoastal non-floodplain grass sedge and herb swamp.

Coastal and subcoastal non-floodplain tree swamp. Coastal and subcoastal non-floodplain wet heath swamp. Riverine Central. Lake Eyre and Bulloo. Western Cape and Gulf. Wet Tropics. Riverine conceptual models—Background. Intertidal and subtidal estuarine and marine ecology Attributes and qualifiers Module 3 Benthic Depth. Terrain morphology. Terrain relative relief. Terrain roughness. Terrain slope. Energy Magnitude.

Structural macrobiota composition. Substrate composition. Substrate consolidation. In many wetlands, nutrient availability is dramatically altered by agriculture or other practices that increase nutrient loading, contributing to changes in ecosystem structure and function.

Through processes like denitrification and plant uptake, wetlands can help remove some of this excess nitrogen introduced to wetland and aquatic ecosystems.

Because of the predominance of water and anaerobic conditions in wetlands, the organisms living there, especially rooted plants, often exhibit remarkable adaptations to deal with the stresses imposed by flooding. This high primary production, in turn, supports high rates of secondary production, rates that can exceed those of terrestrial ecosystems Turner Gaseous transport results in the flow of oxygen from the atmosphere to the roots, and carbon dioxide and methane from the roots to the atmosphere.

Wetlands exist along soil-moisture gradients, with wetter soils at lower elevations and drier soils at higher elevations.

Wetland plant communities develop in response to this environmental gradient based primarily on their individual abilities to tolerate flooding and anaerobic soils but also in response to biotic interactions with other species. Establishment of plant species along an environmental gradient can contribute to sharp plant zonation patterns, as can be seen in coastal wetlands where species separate out along an elevation gradient in response to differences in flooding and salinity Figure 4.

The development of these productive and often diverse plant communities fuels complex food webs that not only sustain microbial communities through large inputs of detritus to wetland soils but also support diverse communities of animals that utilize wetlands for part or all of their lives Figure 5.

Detritivores, such as shredding insects and crayfish, can utilize dead plant material as their primary energy source, while others e.

Herbivory of algae by invertebrates and small fish and of plant biomass by some invertebrates, birds, and mammals e. Secondary production by these primary consumers supports higher trophic levels, including predatory insects, fishes, reptiles, amphibians, birds, and mammals. Figure 5: Example of a food web in a coastal salt marsh This food web of a marsh in Georgia, USA, lists the important primary producers, herbivores, and carnivores in order of importance. As awareness of wetland ecosystem services and values has increased, wetland ecological research also has increased.

Wetland ecologists examine interactions between species and their environment, recognizing the important role that hydrology plays in shaping the physicochemical environment and biological communities in wetlands. Within that framework, ecologists can examine a near-endless array of ecological topics, from the physiology of species coping with flooding stress and anoxia to species interactions, to the impacts of and feedbacks to global climate change. The diversity of wetland types, the biodiversity they support, and the numerous functions they provide make wetlands an exciting and rewarding arena in which to explore fundamental ecological questions.

And it is this science that informs efforts to manage, restore, and conserve the wetlands of the world. Conner, W. Gopal, et al. Costanza, R. The value of the world's ecosystem services and natural capital. Nature , — Cowardin, L. Dacey, J.

Pressurized ventilation in the yellow waterlily. Ecology 62 , — Finlayson, M. Wetlands: Characteristics and Boundaries. Edited by G. Gurt et al. Odum, W. Nature's pulsing paradigm. Estuaries 18 , — Teal, J. Energy flow in the salt marsh ecosystem of Georgia. Ecology 43 , — Turner, R.

Intertidal vegetation and commercial yields of penaeid shrimp. Transactions of the American Fisheries Society , — Introduction to the Basic Drivers of Climate. Terrestrial Biomes.