Riparian Vegetation

We study the links among different geomorphic processes that affect river valley landscapes in the Colorado River downstream from Glen Canyon Dam, Arizona. Dam-released flows affect the deposition and retention of sandbars that serve as sources for other sand resources, such as windblown sand dunes, throughout the Colorado River ecosystem.

The Grand Canyon Monitoring and Research Center offers a collection of data resources and online tools -- including web maps, applications, and other content -- that convey scientific information related to on-going monitoring of the Colorado River. Some applications are a culmination of long-term monitoring work, while others are developed around more a specific set of information usually derived...

Introductions of bio-control beetles (genus Diorhabda) are causing defoliation and dieback of exotic Tamarix spp. in riparian zones across the western U.S., yet the factors that determine the plant communities that follow Tamarix decline are poorly understood. In particular, Tamarix-dominated soils are often higher in nutrients, organic matter, and salts than nearby soils, and these soil...

Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological...

Floodplain red gum forests are sites of high biodiversity in arid regions of south Australia. They depend on periodic floods from rivers, but dams and diversions have reduced flood frequencies, leading to deterioration of the trees. We determined the water requirements of red gum trees so environmental flows can be used to restore and maintain the forests. We used measurements of transpiration of...

The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumping. We used...