ROCKY MOUNTAIN LANDSCAPE SIMULATOR (RMLANDS)
Model Parameterization
This section provides a detailed description of the model parameterization for this application and a list of the experts involved in the parameterization process. Included here is a list of values for all model parameters and the basis (i.e., justification) for their settings. Empirical data and analyses employed in the parameterization process are presented as well. Note, understanding the relevance of parameter values requires some level of comprehension of the basic structure of RMLANDS (see RMLANDS Model Overview).
List of Contributing Experts [click here]
This section provides a comprehensive list of the experts that contributed to the model parameterization for this application.
Vegetation Classification Scheme [click here]
This section provides a brief description of the vegetation classification scheme developed for this application and its justification.
Important Definitions [click here]
This section provides some important definitions for terms and concepts employed in the succession-disturbance transition models.
Vegetation Transition Models
This section includes a complete description of the vegetation transition models for each cover type [click on links below]. Each model includes a general ecological description of the cover type and its geographic distribution within the study area, definitions of discrete stand conditions (i.e., seral stage classes), and the rules for succession and disturbance transitions among stand conditions.
• Barren
• Water
• Riparian
• Sparse Pinyon-Juniper Woodland
• Pinyon-Juniper-Oak-Serviceberry
• Ponderosa Pine-Oak-Aspen Forest
• Warm-Dry Mixed-Conifer Forest
• Warm-Dry Mixed-Conifer with Aspen Forest
• Cool-Moist Mixed-Conifer Forest
• Cool-Moist Mixed-Conifer with Aspen Forest
• Spruce-Fir with Aspen Forest
Natural Disturbance Processes
Numerous types of natural disturbance occurred in the study area during the reference period: fire, snow avalanches, windthrow, and a variety of tree-killing insects, fungi and other pathogens (Veblen et al. 1989, Lertzman and Krebs 1991, Veblen et al. 1991a, b, Roovers and Rebertus 1993, Veblen 2000, Romme et al. 2002). This report focuses just on the effects of two major natural disturbances: wildfire and insects/diseases; the impacts of other natural disturbances during the reference period were likely localized in time or space and therefore probably had far less impact on vegetation patterns over broad spatial and temporal scales than did fire and insects/diseases. The most important and coarsest in scale of these natural disturbances was fire (Romme et al. 2000). Hundreds of species of insects, fungi, and other pathogens that cause tree death or damage also inhabited these forests during the reference period (Furniss and Carolin 1977). Any of them may have been locally important on occasion. However, it was not feasible to explicitly simulate more than a handful of insects and diseases in a complex landscape model like RMLANDS. Therefore, we identified four insect species and one insect/disease (pathogen) complex that have had the most frequent and widespread impact on vegetation in the SJNF region. The insects included mountain pine beetle (Dendroctonus ponderosae), Douglas-fir bark beetle (Dendroctonus pseudotsugae), spruce bark beetle (Dendroctonus rufipennis), and western spruce budworm (Choristoneura occidentalis). The three beetles are bark beetles that kill living trees; the budworm is a defoliator that generally does not kill trees directly but weakens them, making the trees more susceptible to subsequent beetle attack, although the budworm may eventually kill trees if the defoliation continues for a long time. Life histories and ecological impacts of these insects are summarized by Furnis and Carolin (1977). The insect/disease complex that we treated is referred to as "pinyon decline." Black stain root rot (Leptographium wagneri) kills or weakens pinyon trees, which then become more susceptible to attack by the pinyon ips beetle (Ips confusus). Pinyon ips also kills pinyon trees directly, without previous infection by black stain root rot, especially if trees are weakened by drought or soil disturbance (Furniss and Carolin 1977). Both kill pinyon only, leaving the juniper, shrub, and herbaceous components intact.
This section includes a complete description of the parameterization of all disturbance processes [click on links below]. Each section includes a general description of the disturbance process and its relationship with climate (if any), as well as a complete listing of the factors affecting disturbance susceptibility, initiation, spread, and mortality. The values for all parameters and the basis (i.e., justification) for their setting is provided. Empirical data and analyses employed in the parameterization process are presented as well.
These sections are coming soon!
• Wildfire
• Pinyon Decline
• Pine Beetle
• Douglas-fir Beetle
• Spruce Beetle
• Spruce Budworm