Vegetation Management of Wetlands

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Vegetation Management of Wetlands
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Methods

• Water Control
• Fire
• Mechanical Treatments
• Mowing, plowing, disking, etc..
• Chemical
• Fertilizer
• Herbicides
• Grazing

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Fire
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Prescribed Burning with moist-soil management or
in impoundments without water control.
Youngsenfire.com
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4 Objectives of Wetland Burns

• Make new green shoots, roots, and rhizomes of
  grasses and sedges available to geese.
• Expose fallen seed for ducks.
• Reduce perennial vegetation and promote good seed
  producers.
• Create deep pools and edge.

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Burns do not affect seed bank
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Types of Controlled Burns

• Cover, surface, or wet burns
• Root burns
• Peat burns

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Cover Burns

• Light burns conducted when water levels are at or
  above the root horizons.
• Benefits
• Release valuable plants for geese, muskrats, and
  nutria, and ducks.
• Somewhat controls cattail and cordgrass
• Stimulates seed production

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Cover Burns
Invasiveplants.net
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Root Burns

• Hotter fires designed to control and replace
  lower-value marsh plants such as southern wild
  rice, common reed, sawgrass, and cattail.
• Conduct burns when marsh soil has dried 8 to 15
  cm deep.

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Root Burns
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Peat Burns

• Conduct during drought or late summer when
  temperatures are hot and ground/vegetation are
  dry to convert marsh to deep-water areas.
• Fire burns down to mineral level.
• Advantage forms small ponds from 0.2 to 0.8 ha
  in size to promote fringe vegetation growth

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What Fire Intensity do you desire based on the
objectives and location?

• Low-intensity (cool)
• High-intensity (hot)

Minnesota DNR
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Nebraska Waterfowl Management
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When?

• Preflood burns to remove ground litter and woody
  material
• Before growth
• Rotate burned areas and no more than 1/3 of area
  each year.

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When to avoid?

• Avoid extensive burning
• During and just before the waterfowl nesting
  season (April-June).
• Where erosion is a problem.
• During drought years.

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Chesapeake Bay Region

• Burn later in winter, before March 1
• Every 3 years
• In coastal marshes, burn when salinity is
• 7 to 12 ppt.
• Drain water, burn, flood with 30-60 cm of water.

Reason Encourages growth in Olney 3-square,
American bulrush, and Saltmarsh bulrush and
discourage saltgrass and saltmeadow cordgrass.
www.wam.umd.edu
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Other Areas

• Vegetation Dependent
• Big cordgrass produces enough biomass to burn
  every year.
• Black needle-rush burns well
• every 3-4 years
• Cattail control is best when conduct summer
  drawdown and burn.
• Common reed burn in late fall.

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Woody Vegetation
Burn in late summer or early fall.
www.floridastateparks.org
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Mechanical Treatments to Vegetation
Mowing, plowing, disking Ex. Cut reeds in
August or September for 2-3 consecutive years
to reduce density for 8-10 years.
You can create strips of habitat
You can create strips of habitat
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Mechanical Treatments to Vegetation
www.mcilvainenterprises.com/WetlandMowing.asp
Wetland mowing
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Mechanical Treatments to Vegetation
Explosives Create open water zones In stands of
emergent vegetation.
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Mechanical Treatments to Vegetation
Bottom blanketing spread 15-20 cm layer of sand
or gravel over black sheets of plastic. Expensiv
e and only good for short term control.
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Mechanical Treatments to Vegetation
Shading shade out macrophytes by staking
covers, applying dyes, or increasing turbidity.
Sediment Covers Polyethlene plastic
covers Hypalon Aquascreen Dartek
Surface Covers 8 ml plastic sheeting suspended
by floats Pondweed and coontail control
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Mechanical Treatments to Vegetation
Shading shade out macrophytes by staking
covers, applying dyes, or increasing turbidity.
Dyes can be successful in water greater than 1m
deep.
Turbidity Use Carp, but who wants carp!
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Mechanical Treatments to Vegetation
Fertilize Especially in southern areas, add 20
kg/ha of triple superphosphate before growing
season and every 10 days to produce microscopic
(plankton algae) that shades out submerged plants.
But.
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Mechanical Treatments to Vegetation
Herbicides Usually use as a last resort
amphibious excavator
www.dnr.state.md.us/.../gpmgb_stamp_funds.asp
Wetland after herbicide application
rwmetrowatershed.govoffice.com
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Mechanical Treatments to Vegetation
Herbicides Usually use as a last resort
Area of application
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Mechanical Treatments to Vegetation
Grazing Usually use as a last
resort.-Chincoteague ponies
psybergate.com/.../WetlandFix2/part2.htm