Risk-Based Assessment of Landscape Patterns at National Scale

Kurt Riitters, James Wickham, Timothy Wade, and John Coulston

USDA Forest Service Southern Research Station (1), US Environmental Protection Agency (2,3), and North Carolina State University (4)

Advances in landscape ecology, remote sensing, and geographic information systems have enabled status and trends reporting of forest fragmentation and other aspects of landscape spatial pattern at national to global scales.  Until now, the information has been used mainly for ecological monitoring and for indicator-based environmental “report cards,” for example in international reports by the Montréal Process and the Millennium Ecosystem Assessment, and national reports by Forest Health Monitoring, the Heinz Center, and the Environmental Protection Agency.  The reports employ geo-statistical summaries of various metrics (indicators) of forest spatial patterns, interpreted with respect to ecological endpoints such as biodiversity, water quality, and overall ecological integrity.  The authors, as part of the Center for Landscape Pattern Analysis, have supported those efforts by completing several national and global assessments of forest fragmentation, and by conducting research to improve landscape ecological assessment capabilities [see reference list].  For the 2010 US Forest Service Resource Planning Act (RPA) Assessment, the Center is introducing a forward-looking, risk-based analysis of landscape spatial patterns.  The purpose of this paper is to describe and provide a rationale for the approach, with a view towards identifying and discussing key research and application issues during the Threat Assessment Symposium in July 2006.

The first part of this paper provides a synthesis of the science and technology of landscape pattern analysis as it relates to large-area ecological risk assessment.  A key element of landscape assessment is the availability of consistent maps at national to global scales and we summarize the available data and prospects for improvements.  A brief review of pertinent theory in landscape ecology will set the stage for a synthesis of our research over the past decade that has focused on advances in large-area landscape assessment protocols.  Because future risk is tied directly to current conditions, we also provide an overall summary of forest spatial patterns in the US today.  Finally, because risk is also driven by landscape change over time, we describe the characteristics of landscape change models that are appropriate for a national risk assessment.

The second part of this paper focuses on the plan for a forward-looking risk assessment of landscape patterns in the 2010 RPA Assessment.  The approach is motivated partly by our pragmatic perspective because this is a real-world risk assessment that must be completed in less than two years without substantial funding.  The plan makes the best use of the available data and does not rely on data or research results that will not be available.  Motivation comes also from a top-down assessment perspective that is consistent with a multiple-scale landscape ecological view of risk to all ecological endpoints in forested ecosystems.  A novel feature of our approach is that it focuses on pattern itself, rather than on the endpoints that depend on pattern; if a landscape-scale forest pattern changes substantially, then all of the pattern-dependent ecological processes embedded in the landscape are at risk, even if all of the fine-scale details cannot be predicted. The plan is to use relatively coarse-scale data and models to identify specific locations at highest risk, and which aspects of forest pattern are at risk.  The expectation is that local to regional cases of interest will receive more detailed follow-up investigation, if warranted.  In summary, our assessment is designed to identify specific locations for remediation or prevention, to suggest general strategies for landscape pattern management that will be most effective at those locations, and to assist in prioritization of efforts by national policy formulators and land management agencies.  We will use examples drawn from the literature of biodiversity, water quality, and invasive species to demonstrate these concepts and contrast them with traditional bottom-up approaches to ecological risk assessment.

Tuesday Morning Plenary

corresponding author:

Kurt Riitters
USDA Forest Service
3041 E. Cornwallis Road
Research Triangle Park, NC 27709
919-549-4015
kriitters@fs.fed.us

note: oral presentation only