17 Jan2010

Overstory #223 - Conducting landscape assessments for agroforestry

Written by By Gary Bentrup, Mike Dosskey, and Gary Wells.

Landscape assessment illuminates relationships between landscape structure, environmental problems, and agroforestry opportunities.

Purpose

Landscape assessments describe existing resource conditions and trends within a larger planning area and identify opportunities to produce environmental benefits with strategically placed management activities, including agroforestry practices. In this Agroforestry Note, we:

Explain why assessing the landscape is important for agroforestry
Describe a basic landscape assessment process
Discuss ways to use landscape assessments for agroforestry

Why assess the landscape?

Landscape assessments provide a way to understand the relationships between landscape structure, environmental problems, and agroforestry opportunities. Landscape structure influences the sources and movement of organisms, water, air, and materials across the landscape (see AF Note 38 link below). By understanding the sources and flows of these things, landscape structure can be modified with agroforestry practices to produce environmental benefits that can only be produced at the landscape scale such as improving water quality in a watershed or linking habitat patches with a wildlife corridor. Tree-based systems like agroforestry take time before the benefits start to accrue. Consequently, it is critical to locate agroforestry in appropriate locations without trial and error. In some cases, agroforestry practices may also create negative impacts such as excessive woody debris in streams or nuisance wildlife. Assessments can be used to identify where potential problems might occur so they can be avoided or minimized while maximizing environmental benefits. Assessments provide a way to target limited resources on areas that have a higher probability for success.

Landscape assessments

Assessments identify key resource conditions in a landscape:

Problems and where they occur
Opportunities and where they occur
Sources and causes of the problems
Where and how resources flow across the landscape
Structure of the landscape and how it controls sources and movement

In addition, assessments that are repeated can be used to follow trends or changes in these conditions over time. A process for conducting landscape assessments is provided on the adjacent page. Links to data sources and example assessments can be found at the end of this note. Reviewing existing assessments can provide useful ideas for conducting your own assessments.

Often, several assessments are necessary to adequately identify problems and ways to address them. For instance, one assessment may determine nitrate source areas and flow pathways that are contributing to a surface water quality problem. Another assessment might identify locations where riparian forest buffers are most effective at filtering and treating nitrate from runoff. By overlaying or merging these two assessments together, the composite assessment can identify locations where nitrate runoff is a greater problem and where buffers will be a more effective mitigation measure.

Using landscape assessments

Assessments are a key step in developing a landscape or watershed plan that can serve as a coordinated roadmap for planning conservation practices (see AF Note 20 link below). You can also target practices to landowners whose properties were identified in the assessments as the most suitable or critical areas for conservation. Targeting landowners is particularly important for environmental benefits that require the installation of practices at specific locations across the landscape in order to achieve a significant, large-scale impact.

If a landscape or watershed plan is not developed, assessments can still be used when a landowner comes into an agency office for conservation assistance. Assessments can be used to determine if the landowner's objectives can be effectively achieved on their property. By placing the property into the larger landscape context, the assessments may reveal a need to coordinate efforts with other landowners in order to achieve those objectives. Assessments may also indicate other objectives that could be achieved on the property that the landowner may not have initially considered.

Achieving multiple objectives

Landscape assessments can help to produce environmental benefits with even greater efficiency by identifying locations where multiple objectives can be accomplished simultaneously. At these locations, agroforestry can generate more benefits from each installation. To find them, simply overlay the individual assessments and determine where different objectives can be addressed at the same locations.

Getting started

Although you may not have the time or resources to personally conduct landscape assessments, check with your local resource agency or planning organization to see if there are GIS specialists who can assist you with the assessment process. See below for examples of assessments. Data for conducting landscape assessments is usually available from state-operated GIS clearinghouses. Landscape assessments are best developed with participation from a variety of resource experts and stakeholders. Once assessments are completed, they can be used repeatedly to assist many planning and design efforts.

Original Source

This article was excerpted with the kind permission of the publisher from:

Bentrup, G., M. Dosskey, and G. Wells. 2008. Conducting landscape assessments for agroforestry. Agroforestry Note 39. USDA National Agroforestry Center (NAC), Lincoln, Nebraska.

About the Authors

Gary Bentrup is a Research Landscape Planner with the USDA National Agroforestry Center. His research interests include developing and evaluating a conservation buffer planning methodology for agroforestry systems. Gary's projects include creating tools for designing and managing multi-purpose buffers for economic, ecological, and social objectives. E-mail: gbentrup@fs.fed.us

Michael Dosskey is a Research Riparian Ecologist with the USDA National Agroforestry Center. He conducts research on tree-based buffer systems to mitigate agricultural nonpoint source pollution and develops tools for assisting managers with placement and design of buffers for effective pollution control and optimization with other ecological and production functions. E-mail: mdosskey@fs.fed.us

Gary Wells is a Landscape Architect with the USDA National Agroforestry Center. He provides landscape architecture services to technology transfer and research programs at the National Agroforestry Center. His areas of expertise include landscape-scale planning and design, stream corridor restoration, biotechnical streambank protection, and visual simulation. Gary assists in the development of planning and design tools for the comprehensive buffer planning methodology project and in the development and instruction of workshops and Employee Development Courses for the NRCS. E-mail: gary.wells@ne.usda.gov

Additional information

Instructional books
GIS for Landscape Architects by K. Hanna, 1999. ESRI Press.
Managing Natural Resources with GIS by L. Lang, 1998. ESRI Press.
GIS for Environmental Management by R. Scally. 2006. ESRI Press.

Related Agroforestry Notes
AF Note 20: Planning Agroforestry Practices. USDA National Agroforestry Center.
AF Note 38: Landscape Planning for Environmental Benefits. USDA National Agroforestry Center.
AF Note 40: Guidelines for Fitting Agroforestry into the Landscape. USDA National Agroforestry Center.

Example assessments
Agroforestry Product Assessments http://www.unl.edu/nac/research/2002agroforestrygis.pdf
Riparian Connectivity Assessment http://www.unl.edu/nac/research/2004riparianconnectivity.pdf
Water Quality Assessment http://www.unl.edu/nac/research/2006soilsurveys.pdf

Spatial data sources
Geospatial One Stop: http://gos2.geodata.gov/wps/portal/gos
National Geospatial Data Clearinghouse: http://clearinghouse1.fgdc.gov/
USDA Geospatial Data Gateway: http://datagateway.nrcs.usda.gov/