Counting marmots…
Combines remote sensing, thermal imaging, and geophysical methods to characterize floodplain hydrogeology and nitrogen cycling in riparian zones, while connecting to land management concerns around cottonwood forest conservation, grazing, and watershed protection in the Gunnison Basin.
Riparian zones are the ribbons of life that follow streams and rivers through otherwise drier landscapes. In the Gunnison Basin and across the Rocky Mountain West, these narrow corridors — including the streambed, the saturated soils flanking the channel, and the broader floodplain where groundwater and surface water mingle — support a disproportionate share of the region's biodiversity. Cottonwoods (Populus angustifolia, the narrowleaf cottonwood, and Populus fremontii, the Fremont cottonwood) are the keystone trees of these systems, while willows, water birch (Betula occidentalis), and rare plants like Ute Ladies' Tresses (Spiranthes diluvialis) depend on the seasonal flooding and shallow water tables that floodplains provide. Understanding how water moves through these corridors — and how land use, grazing, and infrastructure alter that movement — is fundamental to managing mountain ecosystems in a changing climate.
A few key ideas help make sense of the research that follows. The riparian zone itself includes not only the visible stream but also the boggy margins and subsurface flow paths that deliver dissolved organic carbon and nutrients to the channel. Within the floodplain sediments, certain spots act as nitrogen cycling hotspots — biogeochemically active patches where groundwater mixing with surface water drives enhanced transformations of nitrogen, often controlling water quality downstream. The physical architecture of the floodplain — the layered sands, gravels, and silts left behind by meandering rivers — governs where these hotspots form.
Researchers increasingly characterize this hidden architecture using remote and minimally invasive tools. Thermal imaging uses infrared cameras to detect temperature contrasts at the ground surface; because groundwater entering a stream is typically cooler in summer and warmer in winter than surface water, thermal cameras can locate seeps and springs. Structure from motion photogrammetry stitches together overlapping aerial photographs — often taken from drones — into precise three-dimensional models of terrain and vegetation. And linear mixed effects models are a statistical workhorse for ecological data, allowing scientists to separate the effects of, say, soil type or genotype from the effects of treatment or location when measurements are nested within sites or individuals.
Early land-management studies established that riparian systems in the interior West had been substantially degraded by a century of livestock grazing and infrastructure development, and that recovery was possible but slow. A long-term USFS experiment on a depleted sagebrush-steppe riparian system documented how grazing exclusion combined with woody plantings could restart riparian recovery . Around the same time, local advocacy and planning documents — including correspondence to Gunnison County commissioners regarding the paving of Cottonwood Pass — captured the tension between development pressure and riparian conservation that has shaped the basin's land-use history . Practical field guides for identifying and monitoring riparian graminoids gave managers the tools to assess utilization and recovery in the field .
Streambed and boggy areas around streams as well as uphill water flows that are critical regions for DOC concentrations
Biogeochemically active zones in riparian floodplains where enhanced nitrogen transformations occur due to groundwater-surface water interactions
Use of infrared technology to measure surface temperatures of objects
Geometric ground formations created by freeze-thaw processes in alpine environments
Period required for sagebrush to recover to pre-fire conditions after burning
Safety procedures including isolation, testing, and capacity restrictions to enable field research during pandemic
Statistical model accounting for both fixed and random effects to analyze hierarchical or repeated measures data
Assessment of the amount and character of native Fremont cottonwood forest remaining on the mainstem floodplains in 26 subbasins using geographical in...
Forward Looking Infrared thermal photography combined with machine learning data sculpture techniques to visualize temperature patterns in periglacial...
Motion-activated camera deployment to detect and monitor presence of snow leopards and other wildlife in remote mountain environments.
Spatially Continuous Riverbank Erosion and Accretion Measurements (SCREAM) software used to analyze channel masks and create centerlines and change ar...
Use of small unoccupied aircraft systems with thermal infrared cameras to identify groundwater discharge zones in stream corridors through temperature...
Integration of historical aerial photography, LiDAR data, and multispectral imagery to track channel migration and identify abandoned floodplain featu...
http://www.fs.fed.us/rm/pubs_int/int_rp492.pdf?Warren P. Clary, Nancy L. Shaw, Jonathan G. Dudley, Wictoria A. Saab, John W. Kinney, Lynda C. Smithman...
Ralph E Clark III. November 22, 1996.
Technical report. Topics: photographic utilization guide, riparian. Agencies: USFS. Cites 1 external work.
The dataset is comprised of grain size, bulk density, carbon and nitrogen content of soils sampled on the floodplain of the East River 4 to 11 km down...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The East River is an agricultural tributary to the Lower Fox River and the Environmental Protection Agency (EPA) Green Bay Area of Concern (AOC) in no...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
On the ecological-statistics side, foundational methodological work by Read et al. (Read et al., 2016) demonstrated that genetic variation nested within species can strongly bias inferences about species-level effects on ecosystems. When this nested structure is ignored, researchers reach incorrect conclusions about species effects in up to 20% of cases, and overestimation can reach 60% in some scenarios — a finding directly relevant to riparian work where dominant trees like cottonwoods show strong within-species genetic structure along river corridors.
A central thread in recent East River research is that floodplains are far more heterogeneous than watershed models typically assume, and that this heterogeneity matters for both water and nutrients. Malenda et al. (Malenda et al., 2019) compared two meanders along the upper East River that shared sediment source, vegetation, and climate but had divergent migration histories. Although their bulk hydraulic conductivities differed by less than an order of magnitude, groundwater flow patterns and residence times differed substantially because of the internal layering and orientation of buried sediments. Ground-penetrating radar successfully mapped the gravel deposits and abandoned channel fills that route subsurface flow, and a multi-temporal remote sensing analysis — combining historical aerial photography, LiDAR, and multispectral imagery — tracked river migration and identified abandoned channels from 1955 to 2015 (Malenda et al., 2019). The practical implication is that two meanders that look similar from the air can process water and nutrients very differently.
Complementary work by Briggs et al. (Briggs et al., 2018) showed that drone-based thermal infrared sensing can pinpoint preferential groundwater discharge zones at scales from centimeters to whole watersheds in remote mountain stream corridors. Structure-from-motion processing of drone imagery, anchored with ground control points, produced digital elevation models precise enough for groundwater flow modeling. A dye-tracing experiment confirmed that substantial groundwater enters the channel over roughly 75 meters where the Peeler fault intersects the stream — a concrete demonstration that geologic structure controls where the most biogeochemically active patches of the riparian zone form.
Finally, Read et al. (Read et al., 2016) showed that incorporating nested genetic structure into mixed models increased explanatory power roughly twofold for mammal browsing in Eucalyptus, threefold for leaf area in Populus, and tenfold for branch number in Picea, with the advantage growing as heritability increased. For cottonwood-dominated riparian forests, where genotype influences leaf chemistry, herbivory, and decomposition, this argues for treating within-species variation as a real driver of ecosystem function rather than statistical noise.
The temporal trajectory of the field is clear. Early work in the 1980s and 1990s focused on documenting degradation and testing restoration practices on the ground Response of a Depleted Sagebrush Steppe Riparian System t.... Studies in the mid-2010s introduced new remote and geophysical tools — drones, thermal cameras, ground-penetrating radar, and multi-temporal imagery — that allowed researchers to see floodplain architecture and groundwater discharge patterns at unprecedented resolution (Briggs et al., 2018) (Malenda et al., 2019). Most recently, since 2020, work has shifted toward intensive, long-term monitoring of cottonwood populations as living indicators of floodplain change. Worsham et al. (Worsham et al., 2020) reported tagging, measuring, and geolocating 4,200 trees across the East River watershed, building a baseline for tracking how individual trees respond to flow regime, drought, and disturbance over decades. Inouye (Inouye, 2020) documented how RMBL adapted COVID-19 field protocols to maintain roughly 60% of normal research activity, preserving the continuity of long-term datasets that floodplain and riparian studies depend on.
Looking forward, the field is moving toward integrating these high-resolution physical maps with biological and biogeochemical measurements — linking where groundwater discharges to where nitrogen is transformed, and ultimately to where cottonwoods establish and persist.
Several large questions remain. How will declining snowpack and earlier spring runoff reshape the groundwater-surface water exchange that sustains cottonwood recruitment and floodplain nitrogen processing? Can the heterogeneity revealed by geophysics and remote sensing be incorporated into basin-scale models without losing tractability? How much of the variation in cottonwood performance along the East River reflects genetic differences among trees, as opposed to local hydrology and soils — and does that genetic variation buffer or amplify the response to climate change? Finally, how do legacy land uses — historic grazing, road building, and mining-related contamination such as that addressed by uranium and thorium tailings standards Health and Environmental Protection Standards for Uranium... — continue to shape recovery trajectories in riparian corridors today? Answering these questions will require sustained, multi-decade monitoring of the kind now being built in the East River watershed.
Briggs, M.A., Dawson, C.B., Holmquist-Johnson, C.L., Williams, K.H., Lane, J.W. (2018). Efficient hydrogeological characterization of remote stream corridors using drones. Hydrological Processes. →
Inouye, D. (2020). Field Research in the Time of the Pandemic. Mountain Views Chronicle. →
Malenda, H.F., Sutfin, N.A., Guryan, G., Stauffer, S., Rowland, J.C., Williams, K.H., Singha, K. (2019). From Grain to Floodplain: Evaluating heterogeneity of floodplain hydrostatigraphy using sedimentology, geophysics, and remote sensing. Earth Surface Processes and Landforms. →
Read, Q.D., Hoban, S.M., Eppinga, M.B., Schweitzer, J.A., Bailey, J.K. (2016). Accounting for the nested nature of genetic variation across levels of organization improves our understanding of biodiversity and community ecology. Oikos. →
Worsham, M., et al. (2020). A Brief Escape to Normalcy: A Summer at RMBL. Mountain Views Chronicle. →
Images were processed in Agisoft Metashape Software to derive a georeferenced dense point cloud and 3D model, then orthorectified and combined into a ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
This dataset provides the tabular summary of analysis of an alluvial floodplain reach of the East River, downstream of Gothic, CO near Crested Butte. ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
The U.S. Geological Survey collected low-altitude airborne thermal infrared data and visual imagery via a multirotor, small unoccupied aircraft system...
The East River is an agricultural tributary to the Lower Fox River and the Environmental Protection Agency (EPA) Green Bay Area of Concern (AOC) in no...
This dataset provides four sets of geotiffs used for the mapping and analysis an alluvial floodplain reach of the East River, downstream of Gothic, ...
The Southern Rockies LCC is home to narrowleaf cottonwood (Populus angustifolia), common at elevations above 1800 m, and Fremont cottonwood [a common ...
This dataset contains macroinvertebrate sampling data for the wetlands in the Cottonwood Lake Study Area, Stutsman County, North Dakota. This dataset ...