Inventory and Monitoring of Terrestrial Riparian Resources in the Colorado River of Grand Canyon: An Integrative Approach Annual Report

Kearsley, Michael; Cobb, Neil; Yard, Helen; Lightfoot, David; Carpenter, Geoff; Brantley, Sandra; Frey, Jennifer

Here we present results from the first year of collecting data on the status of terrestrial riparian resources in the Colorado River corridor of Grand Canyon National Park. The data included cover aspects of the vegetation, breeding birds, mammals, arthropods, and herpetofauna that occur in habitats affected by the operation of Glen Canyon Dam within the Park. By collecting these data within the same sites at the same time, it is hoped that we will develop a better understanding of how the system functions, how organisms interact across taxonomic lines, and how these relationships are affected by the operation of the dam. The data are intended for use as the baseline for monitoring of these resources over the long term. As such, their true utility will not be evident until they are compared to data collected in 2002 and 2003. However, we are able to look for relationships among resource groups, especially between aspects of the vegetation in the sites and the abundance and species richness of the faunal components. The data were collected in a series of research river trips organized and outfitted by the Grand Canyon Monitoring and Research Center. Table 1 lists the trips taken, and the work performed on those trips. Some supplemental data was collected on arthropod and herpetofaunal distribution during a research trip carried out as part of the “Bird-Bug” project of Yard and Cobb. Within this report, each taxonomic group is covered in a separate section by the P.I. responsible for that group. The purpose, objectives, methods, and results from the studies in 2001 are described, and a summary of the results are given. The next section covers the integration of faunal data with vegetation structure data and tests for concordances among the composition of the vegetation and the animal groups. The last section is a description of the problems encountered in methods and equipment in 2001, and a description of how we will work around these next year.