Overview of Wetland Types Flashcards
1
Q
Seasonally Flooded Bottomland Hardwoods Cypress/Tupelo (SFBH/CT)
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- Bottomland hardwood wetlands are forested wetlands composed of trees, shrubs, broadleaf herbaceous plants, and grasses that withstand flooding of various depths, duration, and times.
- This is the predominant wetland type in the Lower Mississippi Alluvial Valley (LMAV).
- When selecting tree species for planting, susceptibility of flooding and flood tolerance of species should be considered.
- If water control is possible on bottomland hardwood sites then it is called a greentree reservoir.
- Greentree reservoirs should only be flooded during dormancy, usually December 1 to March 15 in Mississippi.
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Q
Seasonally Flooded Bottomland Hardwoods
Cypress/Tupelo (CT)
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- Early fall flooding can be more detrimental than late spring flooding.
- When managing greentrees, flooding and draining at the same time annually should be avoided.
- Water depth, duration of flooding, and flood timing should be changed each year.
- The reservoir should be left dry 1 in 4 years.
- Improper flooding will result in tree stress and over time will kill desirable oaks and favor flood tolerant trees such as tupelo and cypress.
- Swollen and cracked trunks at water level, acorn crop failure, dead branches, and yellowish leaves are signs of tree stress and improper flooding.
3
Q
Moist-Soil Wetlands (MS)
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- Moist-soil wetlands have historically occurred where openings existed in bottomland hardwoods.
- Forest openings were often caused by high winds, catastrophic floods, beavers, fires, etc.
- Man-made impoundments are commonly managed as moist-soil wetlands.
- Moist-soil areas are typified by seed-producing annuals such as smartweeds, wild millets, panicums, and sprangletop.
- Planting moist-soil areas is not necessary because native plant seeds are abundant in frequently flooded soils.
- Over 2500 pounds per acre of seed can be produced in a properly managed moist-soil area.
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Q
Moist-Soil Wetlands (MS)
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- Over time, plant succession will favor perennials and moist-soil areas will need to be disturbed.
- If more than one moist-soil area is being managed, it is best to stagger draining and flooding between units.
- This will increase plant diversity, prolong habitat availability, and increase wildlife benefits.
- Of 156 species of birds that use moist-soil, 131 prefer water water depths 10 inches or less.
- Varying depth, duration, and timing will provide the best results.
5
Q
Emergent Marshes (EM)
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- Emerging marshes are generally 6” to 3’ deep and contain vegetation rooted in soil that emerges above the water surface.
- Emergent plants include cattail, bulrush, spikerush, and sedges.
- These marshes are valuable as nesting and brood rearing habitat for resident wading birds.
- They also provide feeding, resting, and roosting habitat for migratory shorebirds and waterfowl.
- Emergent marshes are often managed in rotation with moist-soil areas.
6
Q
Emergent Marshes (EM)
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- Maximum use of emergent marshes takes place when plant cover reaches 50%, leaving 50% open water.
- This is called a hemimarsh.
- As marsh succession occurs, a marsh will move from open marsh to hemimarsh to predominately emergent cover.
- Emergent marsh should be manipulated when invading woody plant stems are 2-3 inches in diameter.
7
Q
Emergent Marshes (EM)
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- Disturbance is best accomplished by bushhogging and heavy disking.
- This will set succession back to the grass stage.
- This area can then be managed for moist-soil while another area is allowed to become emergent marsh.
- Water levels of emergent marshes can be drawn down in late summer and early fall to provide mudflats and shallow water for migrating shorebirds and teal.
8
Q
Shrub/Scrub Swamps (SS)
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- Shrub/scrub swamps usually contain 6” to 24” of water during the growing season.
- They are typified by willows, buttonbush, other woody species, and perennial herbaceous vegetation.
- In the LMAV, shrub/scrub swamps are often transitional between emergent wetlands and forested wetlands.
- Decaying leaves provide substrate for invertebrates which in turn provides food for waterbirds, fish, amphibians, and other wetland wildlife.
9
Q
Shrub/Scrub Swamps (SS)
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- Studies have found over 25 pounds of invertebrates in an acre of flooded willows.
- Buttonbush seeds are often fed upon by wood ducks and mallards.
- The primary value of shrub/scrub is thermal roosting cover for waterfowl.
- On cold nights, the low, thick vegetation helps retain heat.
10
Q
Microtopography/Depressions
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- Historically, flooding in the LMAV resulted in shallow ridge/swale topography and isolated depressionial areas.
- This is often referred to as microtopography.
- Microtopography is important because it can provide valuable habitat for amphibians and feeding waterbirds.
- When creating microtopography, the goal is to create as much variation in depth, duration, and timing of flooding as possible.
- This can be accomplished by digging isolated depressions, digging depressions within other wetland types, creative borrowing when constructing dikes, and by diking small, suitable areas.
11
Q
Microtopography/Depressions
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- Depressional wetlands found at high enough elevations to escape seasonal flooding are often called fishless ponds.
- These areas are valuable for amphibians since no fish or bullfrog tadpoles are present to feed on eggs or young.
- Water budgets for the Mississippi Delta have shown 3’ depressions will maintain some water 9 out of 10 years.
12
Q
Deep Open Water
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- Deep, open water is generally 3’ or more deep and is usually a river, slough, brake, bayou, or oxbow lake.
- These wetlands are valuable as fisheries and also provide resting and roosting cover for waterbirds.
- Deep, open water is generally not limiting, but can provide valuable habitat in dry years.
13
Q
Wetland Complexes
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- A variety of wetland types located in close proximity will ensure that each wetland species can meet its physiological requirements at each stage of its life.
- Most managed tracts are not large enough to provide all the previously mentioned wetland types.
- Different wetland types should be provided and steps should be taken to provide wetland types that are not available within adjacent areas.
14
Q
Wetland Complexes
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- Studies indicate that a mallard must have all the resources needed for survival within a 12-mile radius.
- A good goal when planning is to provide all of the wetland types within a 12 mile radius.
- The most benefit occurs when each wetland type is in several stages of succession.
