Final Reports: Modeling Woody Plant Regeneration and Debris Accumulation under Future Streamflow and Wildfire Scenarios in the DLCC
Executive Summary: Riparian ecosystems are vital components of the semi-arid landscape because woody riparian plants provide resources that are absent in adjacent vegetation types. Historically, flood played a key role in shaping the composition and structure of riparian forests. In recent decades, however, the frequency and magnitude of floods has decreased and the timing of peak discharge has been altered. In addition, wildfire has increased in importance as an agent of disturbance along many streams. We initiated this study to increase our understanding of fire, flood, and drought processes at our Middle Rio Grande study sites and develop tools that managers of other systems can use to project the response of...
Modeling Woody Plant Regeneration and Debris Accumulation under Future Streamflow and Wildfire Scenarios in the DLCC
Perennial streams in the Desert LCC support riparian trees such as cottonwood (Populus spp) and box elder (Acer negundo) that are critical components of habitat for riparian obligate birds and other wildlife species (Webb et al. 2007). Trees, snags, and fallen woody debris provide nesting and foraging sites for a variety of riparian animals (Bateman et al. 2008, Smith et al. 2012). Riparian trees require occasional floods to create space suitable for germination and are dependent on accessible groundwater for growth and survival (Lytle and Merritt 2004). Studies along the Middle Rio Grande in New Mexico have shown that rates of woody debris accumulation are also influenced by hydrology because floods physically...
Modeling Woody Plant Regeneration and Debris Accumulation under Future Streamflow and Wildfire Scenarios in the SRLCC
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...