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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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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 Riparian forest buffer
What is Agroforestry? …theintentional combining of agriculture and working trees to create sustainable farming systems. Riparianbuffer Forest farming Alley cropping Silvopasture Windbreaks Riparian forest buffer
Riparian Forest Buffer • What: An area of predominantly trees and/or shrubs located adjacent to and up-gradient from watercourses or water bodies • 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. Riparian forest buffer
Why use Riparian Forest Buffers? Riparian forest buffer
Use Riparian Forest Buffers to: • 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 • Increase carbon storage *Source: NRCS National Standard 391 Riparian forest buffer
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. Start Riparian Forest Buffer Wood fiber in established plants (+) Wood fiber growth rate (-) Crop production (non-woody) Woody plant root systems of established plants (-) Non-woody agricultural land Canopy cover and vertical vegetative structure from established plants (+) Carbon storage (-) Later wood fiber growth rate (+) Aesthetics (-) Crop business and support infrastructure (-) Atmospheric CO2 and greenhouse effect Periodic tree removal (+) Arboreal and understory habitat (+) Leaf/debris fall and woody plant mortality (+) Shade I (+) Forest and forest edge wildlife Harvested wood fiber (manufactured wood products) and other tree/understory-related products (-) Income and income stability (individuals and community) (-) Streambank erosion and sedimentation (+) Infiltration of precipitation and soil storage (+) Detritus and large woody debris in streams (+) Trapping of sediment and sediment-attached pollutants (+) Recreation opportunities (-) Stream water temperature (+) Uptake of soil nutrients during growing season (+) Landowner income; contractor income LEGEND (+) Stream fauna, e.g., fish, invertebrates Associated treatment (+) Denitrification of soil nitrates (+) Recreation business and support infrastructure Created by practice (+) Quality of receiving waters Direct effect (+) Income and income stability (individuals and community) (+) Wood-forest business and support infrastructure (+) Aquatic health for humans, domestic and wild animals; reduced costs Indirect effect Cumulative effect pathway (+) increase; (-) decrease Riparian forest buffer
Design Considerations • Three-zone buffer system • Buffer widths and zones influence use and functionality • Minimum zone widths will vary by region Riparian forest buffer
Other Design Considerations • Location • Species • Height • Density • Length • Management and use • Operation and maintenance Riparian forest buffer
Create Shade • Sun angle will vary by season, latitude and, of course, by time of day. • Understand what is happening at the site and plan accordingly. • In mountainous terrain, elevation and topographic shading can influence layout. Riparian forest buffer
Provide detritus and woody debris • Detritus and large debris are particularly important for lower order stream/riparian food chains and downstream effects on higher order streams. • 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. Riparian forest buffer
Create wildlife habitat • 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 Riparian forest buffer
Restore natural plant communities • 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 Riparian forest buffer
Reduce excess contaminants • 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 Riparian forest buffer
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.) Riparian forest buffer
Provide floodplain protection • 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 Riparian forest buffer
Increase carbon storage • 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 Riparian forest buffer
Summary • Riparian forest buffers provide many benefits and their effects are far reaching • Determine the desired purposes and design to optimize those purposes • Many purposes are partly achieved just by virtue of installing the buffer (carbon storage, contaminant reduction, wildlife habitat, detritus) • Use native species where ever possible unless product-required species are needed to achieve a specific purpose…or if adequate native stock is not available Riparian forest buffer
For Additional Information A number of web sites are available to provide more detailed information on riparian forest buffers. Here are a few: • USDA National Agroforestry Centerhttp://www.unl.edu/nac/riparianforestbuffers.htm • The Center for Agroforestryhttp://www.centerforagroforestry.org/practices/rb.php • Association for Temperate Agroforestryhttp://www.aftaweb.org/riparian_buffers.php • USDA Natural Resources Conservation Servicehttp://www.nrcs.usda.gov/wps/portal/nrcs/home Riparian forest buffer
Acknowledgements A partnership of: NationalAgroforestryCenter • "The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at 202-720-2600 (voice and TDD). • To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410 or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer." 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.