COS 150-1 - Using a watershed scale in-situ network to explore factors in soil moisture variability

Thursday, August 10, 2017: 1:30 PM
E141, Oregon Convention Center
Elise C. Osenga, Emily J. Jack-Scott, John Katzenberger and Ellie Barber, Aspen Global Change Institute, Basalt, CO

The interactive Roaring Fork Observation Network (iRON) was established in 2012 to provide in-situ monitoring at a watershed scale within the Southern Rocky Mountains. As of 2016, the network has expanded to include 9 stations that cover the elevational gradient of the watershed: from an alpine 3,680m environment down to a 1,890m montane zone. Each station measures soil moisture at 10, 20, and 52 cm; soil temperature at 20cm; air temperature, relative humidity, and rain. The goal of this project is two-fold. First, the network is intended to generate a long-term observational record that can help identify soil moisture responses to climate change in mountain ecosystems. Second, the network is intended to allow comparisons between soil moisture patterns and other variables within the ecosystem, e.g. plant survival, snowpack, intensity of rain events, etc. Both goals are intended to be of benefit to both researchers and land managers.

As part of the overall water cycle and a key determinant of plant survival in many regions, soil moisture is an important ecological player. Until the current decade, few in in-situ measurements of soil moisture existed. It is the intend of this project to help build this critical but formerly sparse data record.


The iRON data record is too short to allow for statistically significant conclusions to be drawn at this time, but early analysis of the data provides insight into potential relationships between climate change and soil moisture conditions. Data from the iRON’s existing record reveal that date of snowmelt and subsequent saturation of the soil appears to be an important factor in determining soil moisture throughout the following spring and summer seasons, and that the “monsoon” heavy rain events that usually occur at the end of July or start of August are the other main event driving soil moisture levels. Other results of note include: the importance of soil type in retaining soil moisture and the role of elevation in average, average minimum, and average maximum annual temperatures. Colorado sits on a cusp between a region that is projected to become drier with climate change and a region that is projected to become wetter. A better understanding of the relationship between soil moisture (and hence water availability), precipitation, and air temperature can help contribute to a better understanding of how climate change may impact ecology as a whole in this and other mountain watersheds.