Risk-Assessment Methods
This section provides information and example applications for categorizing risk methods, susceptibility/risk rating systems, graph-based connectivity assessments, empirical outbreak projections, population modeling, and other risk-assessment methods. The examples provided in this section illustrate how we categorize risk methods. These examples are based on a range of tools we have used to assess potential impacts of mountain pine beetles at scales from stands to the entire province of British Columbia (B.C.). Although the specific details of the methods differ substantially, they are essentially just different approaches to assessing risk. They differ fundamentally in terms of the degree to which ecological and management processes are taken into account and can be viewed along a gradient (see figure at right). Structural approaches to risk focus mostly on landscape patterns and correlations between past outbreak behaviour and stand structure, whereas functional approaches focus on underlying processes and interactions in the system (cf. distinction between structural and functional habitat connectivity, Taylor and others 1993).
- Susceptibility/Risk-Rating Systems : Susceptibility and risk rating systems classify each stand or location in a landscape according to local characteristics, (e.g., forest age, distance to nearest attack).
- Graph-Based Connectivity Assessment : Examining the network of inter-connections between susceptible host patches can provide a broad perspective of landscape patterns.
- Empirical Outbreak Projection : The development of methods for modeling and analyzing spatially and temporally autocorrelated data such as the historic spread of a bark beetle outbreak across a heterogeneous landscape is a current and active area of research.
- Population Modeling : Population models capture outbreak dynamics by explicitly modeling demographic changes with processes of mortality, birth, dispersal, etc.
- Other Risk-Assessment Methods : It may be possible to interpret other methods for assessing landscape-scale risk of bark beetle outbreaks in the framework presented, such as spatial temporal statistical methods and field experiments.
Encyclopedia ID: p3250
