Conservation Riparian Forest Buffers and Pollution Reduction

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Conservation (Riparian Forest) Buffers and
Pollution Reduction Buffers Are Living
Filters Michael A. Gold / Ranjith Udawatta
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Topics covered today

• Why are riparian forest buffers needed?
• What are the functions of buffers?
• Design considerations
• Types of buffers CSG, WSG, RFB
• Match the design to the situation
• Economic opportunities woody florals
• Buffer installation
• Research findings Udawatta presentation

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Riparian Forest Buffers
Planned combinations of trees, shrubs, grasses,
forbs bioengineered structures designed to
mitigate the impact of land-use on a stream or
lake.
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Riparian Forest Buffer
4 year old RFB
Native Grass
Trees
Shrubs
Planned combinations of trees, shrubs, grasses,
forbs bioengineered structures designed to
mitigate the impact of land-use on a stream or
lake.
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Why are Riparian Forest Buffers Needed in Ag
Landscapes?
Loss of perennial plant cover reduced soil
quality
Leads to NPS pollution of water bodies
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Channel Modifications
Lead to unstable banks channels
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Channel Modifications
Lead to unstable banks channels
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Intensive Livestock Grazing - Unstable Banks
Channels
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Because of watershed modifications Riparian
Forest Buffers are needed
Often no perennial riparian vegetation is left
riparian buffers/filters have to start from
scratch
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True Restoration vs Re-creation of Riparian
Function
Cannot restore ecosystems because landscapes have
been so drastically modified

• Channels downcut widened
• Channels no longer in contact with their flood
  plain
• Water tables lowered

Result - design plant communities that are not
native
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• At landscape level buffers
• 1. Link/Conduit
• 2. Barrier
• 3. Filter
• 4. Sink
• 5. Source
• 6. Habitat
• 7. Income

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Riparian Buffers
Contour Grass Strips Upland Buffers
Grass Waterway
Grass Filters
Stream
Riparian Forest Buffers Only one Conservation
Practice For Improving Stream Ecology
Forest Buffer
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Riparian Management Systems
Streambank Bioengineering
Buffers/filters
Channel Control Structures
Constructed Wetlands
Controlled Grazing
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Factors to Consider Before Designing a Buffer

• Landowner objectives
• Major function(s) of buffer system
• Present condition of riparian area
• Adjacent land-use
• Soils/microrelief of riparian area
• Stratigraphy water table location
• Short/long-term management needs
• Establishment methods planting, direct
  seeding,
• natural regeneration
• Other riparian system tools bioengineering,
• wetlands, channel structures, etc.
• Government programs

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What could be done to improve this stream?
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Buffer Practices
Cool-Season Grass Filter
Riparian Forest Buffer
http//photogallery.nrcs.usda.gov
Photo by T. Schultz
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Two Types of Buffers
Riparian Forest Buffers USDA-FSA - CP 22 NRCS -
391
Grass Filters USDA-FSA - CP 21 NRCS - 393
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Grass Filter Objectives
Remove nutrients, sediment, organic matter,
pesticides, other pollutants from surface
runoff subsurface flow by deposition,
absorption, plant uptake, denitrification,
other processes and thereby reduce pollution
protect surface water subsurface water quality
while enhancing the ecosystem of the water body.
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Cool Season Grasses
Grass Filters
Native Warm-season Grasses Forbs
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Grass filter also part of the Riparian Forest
Buffer (zone III)
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Riparian Forest Buffers
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Riparian Forest Buffers - Functions

• Connect upland and aquatic ecosystems
• Transition zones between upland and aquatic
  habitat
• Areas of trees, shrubs, grasses and other
  vegetation adjacent to water bodies
• One of the most effective tools for addressing
  nonpoint source pollution
• Ideally, buffers are managed to maintain their
  NPS reduction capacity

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Riparian Forest Buffers - Functions

• Filter and retain sediment
• Trap, store and transform chemical inputs from
  uplands
• Provide water storage and recharge of subsurface
  aquifers
• Stabilize streambanks, control stream
  environments and stream morphology
• Reduce flooding and flood damage
• Supply food, cover, and thermal protection to
  fish and other wildlife
• Provide income

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Buffer Impacts Stream Size - I
Buffers have greatest influence on water quality
along 1st - 3rd order streams (smallest size) as
over 90 of stream lengths in a watershed are 1st
- 3rd order This is the zone of erosion and
sediment and solute production and most of this
production passes through the buffer (riparian)
community
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Headwater streams
Rivers
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Buffer Impacts Stream Size - II

• Buffers have greatest influence on aquatic
  habitat along mid-order streams (3-6) (moderate
  size)
• This is a zone of sediment storage and transport
• Channels have sufficient flow and woody debris to
  support an active aquatic community

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Buffer Impacts Stream Size - III

• Buffers have greatest influence on flood
  moderation along highest order streams (6)
• This is a zone of sediment deposition
• Major river flood plains with wide riparian
  forests and wetlands

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Basic Buffer Models
3 zone built from remnant forest buffer
Multi-species Riparian Buffer
3 zone built from scratch
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Riparian Forest Buffer Built from scratch ag
land

• Native Grasses
• Wildlife habitat/cover/forage
• Sediment removal from runoff
• Improve soil infiltration
• No stream shading/ detritus
• Keep out invasive species

• Trees
• Vertical structure/habitat
• Nutrient (including C) storage
• Strong woody roots
• Stream shading/in-stream food

• Shrubs
• Vertical structure/habitat
• Multiple-stems trap debris
• Woody roots
• Little stream shading

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Design Options for Stream Buffers
Stream
Grass filter WSG or CSG
1
2
3
The rest are all Forest Buffer options
4
5
6
Trees
Grass
Shrubs
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Which Design Fits Here?
Conditions Objectives
Headwater prairie stream Gentle banks Upland bird
habitat

• Filter Strip
• Headwaters of prairie streams
• Non-incised channels/gentle
• banks
• Upland game bird habitat
• Potential for forage/biomass
• harvest
• Cool-season vs native warm
• season (better habitat)

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Which Design Fits Here?
Conditions Objectives
Incised channel steep banks, no option for
reshaping, no woody debris in stream. Warm-water
stream

• Filter Strip with Bank-side
• Shrubs
• Incised/vertical banks
• Warm-water stream / no
• shading
• No large woody debris

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Which Design Fits Here?
Conditions Objectives

• Incised channel steep
• banks, no option for
• reshaping.
• Cool-water stream
• Fiber, carbon fix options

• Classic Riparian Forest Buffer
• Non-prairie stream
• Most vertical structure/habitat
• Strong woody roots for
• stabilization
• Effectively trap flood debris
• Shade over stream, lower T0
• Wood products, CCX options

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Which Design Fits Here?
Conditions Objectives

• Existing narrow forested strip
• Cultivated field with 2-5 slope
• Annually created rills
• ephemeral gullies
• Gullies extend through forest
• Control gullies/reduce sediment

Add grass filter strip Cool-season or warm
season Control gullies
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Upland Game Habitat
Horizontal Vertical Structure
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Edge or Forest Species
More Structural Diversity
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General Design Considerations
Tight meanders place buffer outside meander
belt.
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General Design Considerations
Fit to provide straight field or gentle borders
Fill in odd areas (terrace on left)
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General Design Considerations
Along channelized reaches make buffer wide enough
to contain future meander belts.
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Design Considerations - Market Opportunities
Decorative woody florals (2-3 years dogwoods,
curly willow, pussy willow) Nut trees (5-15
years hazel nuts, walnut, pecan) Fruit trees,
shrubs, berries, jellies, wine (3-5 years apple,
elderberry, raspberries) Biomass timber (15-75
years, cottonwood, walnut) Carbon credits - CCX
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Riparian Forest Buffers and Economic Production
One Example Woody florals shrubs with market
value 0.30 0.45 per stem wholesale
Red osier dogwood Cornus stolonifera
Research from Scott Josiah - UNL
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Woody Florals A Third Crop

• Crop to diversify agricultural system
• Protect and enhance environment
• Help address non point source pollution problems
• Rapid growth and reasonably quick return on
  investment
• Good markets but it takes hard work to break in
  to new market areas!
• Low capital costs
• Off season labor requirements
• Can be grown in windbreaks, riparian forest
  buffers or alley cropping configurations

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Woody Florals in Windbreak Plantings
Red Twig Dogwood Photo Scott Josiah, UNL
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Alley cropping with woody florals, Mead, Nebraska
UNL Ag. RD Center Hardiness Zone 4b.
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Scarlet curls willowYield of five harvested
plants
Photo credit Scott Josiah, UNL
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Photo credit Scott Josiah, UNL
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Production Data unpublished, not for
distribution. By 4th/5th harvest most woody
florals producing 20 stems per plant
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Photo credit Scott Josiah, UNL
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COSTS - Unpublished Data from UNL not for
distribution
387 495
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RETURNS - Unpublished Data from UNL not for
distribution
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Woody Component - Establishment
5 perennial rye 7 timothy on crop ground
3-4 ft kill strips with Roundup on pasture ground
10 X 10 ft spacing for trees
10 x 8 ft spacing for shrubs
Make sure maintenance mower fits between rows
Buffer objective maintain trees with ground
cover to reduce erosion
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UMCA Flood Tolerance Lab Screening to Test
Tolerance Between and Within Species
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FTL (old 12 channel version) at HARC
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Maintain flexibility - Design to Fit
landscape Buffer functions Landowner objectives
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Riparian Management Systems
Constructed Wetlands
Channel Control Structures
Buffers/filters
Stream bank Bioengineering
Controlled Grazing
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Streambank Stabilization
Bio Engineering
Hard Engineering
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Awesome Willow
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Stabilized bank 2 months after installation
2 year old bank stabilization installation
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Study of Buffers Stream Bank Erosion
Objective Determine amount of sediment lost from
stream gully banks adjacent to crop fields,
buffers 4 different grazing practices
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Channel-side Paths
Problems of Riparian Overgrazing
Loafing areas associated with trees shade
Cattle in the stream
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Severe Eroding Lengths
Healthy Streams lt 20
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Soil Losses
6X Grass 12X RFB
5X Grass 10X RFB
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• Fencing narrow corridor along stream may be
  sufficient
• Establish 3 dense shrub rows wild plum,
  dogwood,
• ninebark remove fence

NOT FENCED
SOLUTIONS
UNFENCED
FENCED
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Example of Fencing - Continuously Grazed
Limestone bluffs
Creek fenced
Bee hives
Nose pump
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Continuously Grazed
cattle using nose pump
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Continuously
Grazedhttp//www.epa.gov/nps/Section319III/IA.htm
Trout are back!!!
Bigalk Creek NE Iowa
Riparian Forest Buffer
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Buffer System Performance
Buffers remove 95 of sediment
80 of nutrient load
Native warm-season grass better than cool-season
Soil quality greater under buffer than row
crops Soil Structure Infiltration
Rates Perennial Root Biomass Soil
OM Beneficial Microbes
Denitrification Rates Soil Carbon is key!
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Buffer Hydrogeology what makes a good buffer?
Loam
Sand
Sand
Sand
Sand
Hydrogeologic Environment
Till
Till
Till
Lime S
Lime S
Lime S
Lime S
Lime S
Lime S
Residence time Volume contacting buffer
Maximum
Minimum
Poor Buffer
Groundwater Quality Function
Good Buffer
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Buffers have no impact on nutrients that leach
below the root zone
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Bird Use of Riparian Buffers
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5X
40
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1997 Study
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1999 Study
Number of Bird Species
25
20
15
10
5
0
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Rule of Thumb Wider is Better
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Otter Creek Watershed
Where should buffers go?

• Use watershed approach
• Headwater streams provide better opportunities
  than large rivers
• Connectivity matters

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Bottom Line

• Riparian Buffers Work
• Maintain Flexibility
• Design to fit
• Landscape
• NPS problems
• Landowner objectives

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If Riparian Forest Buffers are so beneficial
why are they so difficult to sell? What
information needs still exist?
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Successful buffers depend on voluntary landowner
adoption Issues to consider

• Clean water, but only
• downstream benefits

• Wildlife habitat, but only some

• If no trees, farm after 15 years

• Takes land out of production

• Products?

• After 15 year government
• program, then what?

• Continued management
• Needs too much knowledge?

Need Design Flexibility
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Recommended Readings

• Schultz, R.C., J.P. Colletti, T.M. Isenhart, C.O.
  Marquez, W.W. Simpkins, and C.J. Ball. 2000.
  Riparian Forest Buffer Practices. In North
  American Agroforestry An Integrated Science and
  Practice. H.E. Garrett, W.J. Rietveld and R.F.
  Fisher (eds.). American Society of Agronomy,
  Inc. Madison, Wisconsin. 402 pp.
• Schultz, R.C., T.M. Isenhart, W.W. Simpkins, and
  J.P. Colletti. 2004. Riparian Forest Buffers in
  Agroecosystems Lessons Learned from the Bear
  Creek Watershed, Central Iowa, USA. Agroforestry
  Systems 61 35-50.
• (for copies, contact Dr. Richard C. Schultz
  rschultz_at_iastate.edu)

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Questions?
Water Quality Improvement and Agroforestry
Practices
Ranjith P. Udawatta Center for Agroforestry
University of Missouri www.centerforagroforestry.
org