Nutrient Cycling

USGS Southwest Biological Science Center's Grand Canyon Monitoring and Research Center leadership and PIs prepared a cooperator publication and a presentation that report on modeling results to evaluate potential effects of reservoir management on various resources in Lake Powell and Grand Canyon.

The Grand Canyon Monitoring and Research Center currently functions under a Triennial Work Plan (TWP) which is thoroughly reviewed and vetted both internally within the Center and through the GCDAMP Technical Work Group (TWG) and the Adaptive Management Work Group (AMWG). These advisory panels have been a part of the Glen Canyon Dam adaptive management process since the inception of the GCDAMP...

Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...

Biological soil crusts (biocrusts) are commonly found on the soil surface in arid and semi-arid ecosystems (collectively called drylands). Biocrusts can consist of mosses, cyanobacteria, lichens, algae, and microfungi, and they strongly interact with the soil. These organisms or consortium of disparate organisms, depending on the specific biocrust, are important to the functioning of ecosystems...

Glen Canyon Dam has altered ecological processes of the Colorado River in Grand Canyon. Before the dam was built, the Colorado River experienced seasonable variable flow rates, including springtime flooding events. These spring floods scoured the river bottom and enhanced natural processes that sustained the Colorado River ecosystem. Since the dam’s construction in 1963, springtime floods have...

Reclamation on lands impacted by energy development is complicated and extremely challenging in arid environments due to unstable soils, exotic species, and low and variable precipitation. The reclamation tactics employed by energy operators vary widely and outcomes can differ across plant communities and soil types. In order to address the knowledge gaps regarding how to successfully and...

The Colorado Plateau, centered around the four corners area of the Southwest, and includes much of Arizona, Utah, Colorado, and New Mexico, is a large and important component of U.S. drylands. This important home to mountains, desert basins, dramatic canyons, arid woodlands, and grasslands is also one of North America’s most rapidly warming hot spots, with rates of warming of up to 2-3° C within...

Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...

Tropical forests take in and store more carbon than any other biome in the world, but increasing temperatures may pose a threat to this invaluable service. This research aims to explore how temperature affects key tropical forest functions, such as plant photosynthesis and soil respiration. To do this, the Tropical Responses to Altered Climate Experiment (TRACE) project will use infrared heating...