Riparian Forest Buffer
An agroforestry practice
This presentation was developed by the USDA National Agroforestry Center
Presentation Objectives
Define riparian forest buffer
 Describe the benefits and uses
 Recognize basic design considerations
 Identify potential riparian buffer crops
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What is Agroforestry?
…the intentional combining of
agriculture and working trees to
create sustainable farming systems.
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Forest farming
Alley cropping
Silvopasture
Windbreaks
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Riparian Forest Buffer

What: An area of
predominantly trees and/or
shrubs located adjacent to and
up-gradient from watercourses
or water bodies
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Where: On areas adjacent to
permanent or intermittent
streams, lakes, ponds, wetlands
and areas with ground water
recharge that are capable of
supporting woody vegetation.
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Why use Riparian Forest Buffers?
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Use Riparian Forest Buffers to:
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Create shade to lower water temperatures to improve habitat for
cold water aquatic organisms
Provide a source of detritus and large woody debris for aquatic and
terrestrial organisms
Create wildlife habitat and establish wildlife corridors
Restore natural riparian plant communities
Reduce excess amounts of sediment, organic material, nutrients
and pesticides in surface runoff and reduce excess nutrients and
other chemicals in shallow ground water flow
Provide a harvestable crop of timber, fiber, forage, fruit, or other
crops consistent with other intended purposes.
Provide floodplain protection
*Source: NRCS National
Increase carbon storage
Standard 391
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What are the Effects of Riparian Forest Buffers?
Initial Setting: Former riparian forests and habitat used for
forage, cropland, speculation property, or other non-forest
use. Includes cutover riparian zones within forested areas.
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Wood fiber in
established plants
(+) Wood fiber
growth rate
(-) Later wood
fiber growth rate
Periodic tree
removal
Harvested wood
fiber (manufactured
wood products) and
other
tree/understoryrelated products
(+)
Landowner
income;
contractor
income
(+) Woodforest business
and support
infrastructure
Woody plant
root systems
of established
plants
(+) Carbon
storage
(-)
Atmospheric
CO2 and
greenhouse
effect
(+) Shade
(+) Infiltration
of precipitation
and soil storage
(-)
Streambank
erosion and
sedimentation
(+) Uptake of soil
nutrients during
growing season
(+)
Denitrification
of soil nitrates
(+) Income
and income
stability
(individuals
and
community)
(-) Crop
production
(non-woody)
(-) Non-woody agricultural
land
Canopy cover and
vertical vegetative
structure from established
plants
(+) Aesthetics
(+)
Leaf/debris
fall and
woody
plant
mortality
(-) Crop
business and
support
infrastructure
(+) Arboreal
and understory
habitat
(+) Detritus and
large woody debris
in streams
(-) Stream water
temperature
I (+) Forest
and forest
edge
wildlife
(+) Trapping of
sediment and
sedimentattached
pollutants
(-) Income and
income stability
(individuals and
community)
(+) Recreation
opportunities
LEGEND
(+) Stream fauna,
e.g., fish,
invertebrates
(+) Quality of
receiving waters
Associated treatment
(+)
Recreation
business and
support
infrastructure
(+) Aquatic health for
humans, domestic and
wild animals; reduced
costs
Created by practice
Direct effect
Indirect effect
Cumulative effect
pathway
(+) increase; (-) decrease
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Design Considerations
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Three-zone buffer system
Buffer widths and zones
influence use and
functionality
Minimum zone widths
will vary by region
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Other Design Considerations
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Location
Species
Height
Density
Length
Management and use
Operation and maintenance
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Table. Proportion of National Stream and River Mileage in
Headwater Streams (Leopold, Wolman, Miller, 1964)
Stream Order*
Number of
Streams
Total Length of
Streams (miles)
Mean Drainage
Area (square
miles)**
1
1,570,000
1,570,000
1.0
2
350,000
810,000
4.7
3
80,000
420,000
23
4
18,000
220,000
109
5
4,200
116,000
518
6
950
61,000
2,460
7
200
30,000
11,700
8
41
14,000
55,600
9
8
6,200
264,000
10
1
1,800
1,250,000
Total
2,023,400
3,250,000
N/A
*stream order based on Strahler (1957) method, analyzing maps at a scale of 1:24,000
**cumulative drainage area, including tributaries
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Create Shade
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Sun angle will vary by
season, latitude and, of
course, by time of day.
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Understand what is
happening at the site
and plan accordingly.
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In mountainous terrain,
elevation and
topographic shading can
influence layout.
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Provide detritus and woody debris
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Detritus and large debris are
particularly important for
lower order stream/riparian
food chains and downstream
effects on higher order
streams.
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Placement in close proximity
to the stream or water body
insures that some leaf drop,
twigs, and other detritus (and
eventually large woody
debris) enters the aquatic
system.
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Create wildlife habitat
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Use widths to match
desired conditions
The value of riparian
habitat is greatly
increased if adjacent
upland habitat is created
and complementary
Natural mortality can
increase habitat diversity
and mimic natural
development
Full site functionality
takes time
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Restore natural plant communities
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Wildlife usually benefit
most from a mosaic of
natural plant communities
Connect fragmented
riparian forests.
Isolated patches or short
strips may be poorly
utilized or act as a magnet
for predators
Use native species where
ever possible
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Reduce excess contaminants
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Understand the origin and
boundaries of the source
contaminants and locate
the buffer down-gradient
from them.
Contaminants (sediment,
chemicals, etc.) may be
transported by surface
sheet or concentrated
flows or by subsurface
flows.
Subsurface flows in many
settings bypass riparian
buffer root systems
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Provide harvestable crops
 Marketable products depend on
current and future demand.
 Potential products:
›wood (sawlogs, post, poles,
veneer)
›fiber (pulp, firewood, energy
biomass)
›forage (livestock)
›fruit (nuts, berries)
›other crops (ginseng,
mushrooms, herbs and floral
greenery, etc.)
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Provide floodplain protection
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Riparian buffers reduce
floodwater velocity and
erosive power
Stream debris is blocked
from entering cropland,
grassland, and urban
lands
Roots hold stream banks
and keep the soil in place
Peak storm flows may be
reduced, lowering
flooding levels
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Increase carbon storage
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Riparian buffers are
effective at storing
carbon
Trees grow rapidly in
riparian zones due to
favorable moisture and
nutrient conditions
Net carbon benefits are
realized if the wood fiber
is used for solid wood
products or fuel
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Summary
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Riparian forest buffers provide many benefits and their
effects are far reaching
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Determine the desired purposes and design to optimize
those purposes
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Many purposes are partly achieved just by virtue of
installing the buffer (carbon storage, contaminant
reduction, wildlife habitat, detritus)
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Use native species where ever possible unless productrequired species are needed to achieve a specific
purpose…or if adequate native stock is not available
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For Additional Information
A number of web sites are available to provide more detailed
information on riparian forest buffers. Here are a few:
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USDA National Agroforestry Center
http://www.unl.edu/nac/riparianforestbuffers.htm
The Center for Agroforestry
http://www.centerforagroforestry.org/practices/rb.php
Association for Temperate Agroforestry
http://www.aftaweb.org/riparian_buffers.php
USDA Natural Resources Conservation Service
http://www.nrcs.usda.gov/wps/portal/nrcs/home
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Acknowledgements
This presentation was developed by the
USDA National Agroforestry Center (NAC),
Lincoln NE.
NAC is a USDA partnership between the
U.S. Forest Service and the Natural
Resources Conservation Service.
National
Agroforestry
Center

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A partnership of:
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