Rivers in the SRLCC differ from one another in flow characteristics, levels of regulation, and vulnerability to wildfire; characteristics that will be influenced by climate change (Seager et al. 2007, Mortiz et al. 2012). An understanding of how changes in streamflow and wildfire frequency will affect structure of live and dead woody vegetation is needed to for managers assess the vulnerability of riparian obligate species to climate change. We are developing stochastic transition models for cottonwood trees and snags along the Middle Rio Grande by modifying Lytle and Merritts (2004) stage-structured cottonwood population model. By incorporating influences of flood and wildfire into stage transition rates, we can project future tree and snag density under current conditions and under climate change scenarios. We propose further modifications of this model to create an applied science tool that can be used to model vegetation structure, wildlife habitat, and wildfire risk along streams throughout the Southern Rockies LCC.
Our project objective is to expand cottonwood population models, which we are constructing with data from the Middle Rio Grande, into an applied science tool to predict long-term changes in density of woody vegetation, snags, and woody debris under future streamflow and wildfire scenarios. Agencies will use our results to incorporate future wildfire risk, native plant persistence, and conservation of wildlife habitat into decisions regarding water storage and delivery.