Page prepared in part by Lydia Stranathan, UNC 2026
methods & resultsWe were able to install seven temporary wells across the ranch, from which we collected samples of organic matter, water chemistry, aquatic macroinvertebrates, carbon dioxide, and methane. We radiocarbon-dated and measured the isotopic characteristics of these samples, a process which enabled us to understand the sources of carbon to the food web. We found various macroinvertebrates living underground, including stoneflies, mayflies, caddisflies, chironomids, and others. Some of these species spend part of their life cycles aboveground in the river channel, and others spend their entire larval stage underground in the aquifer.
We found that some of these macroinvertebrates and organic matter had carbon dated to >10,000 years before present, demonstrating the the ancient carbon supplied by the warm springs and delivered from deep in the earth was contributing to modern productivity in the river. To think - that the bugs we find in rivers - have in their bodies the carbon delivered from deep in the earth! This finding demonstrates that rivers are broader and deeper than their channels, and they integrate timespans ranging thousands of years. NSF report |
backgroundAlluvial aquifers, or the places where water is stored belowground in coarse gravels. The alluvial aquifers we study underlie gravel-bed river floodplains such as that at Cement Creek Ranch. These aquifers are dark, cold systems where photosynthesis cannot occur, so carbon entering the system is generally supplied from the water infiltrating in from the river channel. The volume of water infiltrating the aquifer is minimal compared to the volume of this subterranean system Despite being so inhospitable, the aquifers support diverse and abundant large-bodied consumers such as stoneflies.
Rarely, carbon can also come from natural gas, or shale, and from deep in the earth. Connections to deeper levels of the earth can be indicated by warm springs, such as those on Cement Creek Ranch. We studied geologic (ancient) contributions of carbon to macroinvertebrates in the Cement Creek Floodplain, where the potential for both of these contributions was evidenced by warm springs and a shale formation. Our work in the Cement Creek floodplain was made possible by the generous support of David and Chris Baxter, owners of the beautiful Cement Creek Ranch, who let us access the land and constantly assisted with our work. |
Cement creek ranch
This research would not have been possible without the generosity of the Baxters, the owners of Cement Creek Ranch located in Crested Butte, CO, who let Dr. DelVecchia and her team access this floodplain. The work was supported by NSF DEB 2003423.