Sáde Cromratie Clemons is a master’s student in the Geography Department at the University of Colorado Boulder. She studies trees’ environmental and physiological responses to the 2013 Colorado Front Range flood and how these responses can affect large wood recruitment within forests. The goal of her current work is to test new methods for identifying the source of LW recruitment in river corridors. Sáde received her Bachelor of Science in Environmental Science from the University of North Carolina at Chapel Hill, where she worked on various projects related to renewable energy and environmental microbiology. Her interests include hydrology and fluvial geomorphology.
Large wood (LW) recruitment influences the structure of river corridors and is an important component of wood budgets and river restoration. Determining the source location of LW from the watershed is challenging and techniques used to identify source locations are few. Research using dendrochronology and isotope methods to determine the provenance of LW recruited to river corridors has not been adequately explored. This project examines the source of LW deposited in valley bottoms in the Colorado Front Range, USA following a flood that occurred in 2013. The goal is to add on to existing LW sourcing techniques by combining dendrochronology methods with stable isotope methods to determine the source of LW (e.g., near-channel/valley bottom or upslope/hillslope) within a single catchment. We sampled cores from near-channel and upslope trees and sampled pieces of LW in the valley bottom deposited by the flood. Palmer drought severity index (PDSI) was used to show differences in soil moisture over the years. We looked at basal area increment (BAI) and ring width index (RWI) to identify differences in climate-growth relationships that could be attributable to difference in position and species. We also measured d18O to identify differences in source water by positions and species. We compared the BAI and RWI of individual LW samples to standing trees at different positions as a measure of correlation. Our results show climate-growth relationships by position are minimal, but are species-dependent. From the d18O analysis, it is inferred that trees at both positions get their water from the same source. Looking solely at LW correlations between standing tree samples, LW showed more correlation to near-channel trees, however, whether this correlation was due to differences in soil moisture conditions is inconclusive. Dendrochronology and isotope techniques are rarely used to study wood recruitment and should be further studied to provide additional information about identifying LW source locations.