The History and Future of Biological Inventory and Research in the Grand Canyon Region:
Scientific inventory of the biota of the Grand Canyon region began in the late nineteenth century, and intensive biological and ecosystem studies have been conducted since the late 1920s. Biological information exists in the diaries and photographs of early Grand Canyon explorers, particularly those of Edgar Mearns (1884) and Robert Stanton (1889-1890), and through the regional elevation studies of C. Hart Merriam (1889). Early Park naturalists, such as Eddie McKee, began compiling biological inventory data and reporting new taxa in the decades following declaration of the Park. Although several biologists reached the Colorado River between 1889 and 1938, pre-dam Colorado River corridor vegetation was not qualitatively described until Clover and Jotter (1944). Post-dam vegetation was described by the Museum of Northern Arizona (1974-1977) and subsequently by Northern Arizona University (1990-present). Grand Canyon's flora has been summarized periodically, and relatively few new species are likely to be added to the inventory. A lichen inventory of the Grand Canyon region has been completed. Several vegetation maps of the region have been prepared; however, the distribution and ecological function of most plant species remain poorly synthesized.
The region's faunal inventory is reasonably complete for some taxa, but limited for most invertebrate taxa, and individual species distributions and habitats are poorly known. Relatively complete invertebrate inventories (but not distribution data) exist for landsnails (Spamer and Bogan 1994) and butterflies and skippers (Garth 1950). Recently updated distributional inventories exist for aquatic Heteroptera (Stevens and Polhemus in press), tiger beetles (Cicindelidae – Stevens and Huber 2004), and chironomid midges (Sublette et al. 1998). These invertebrate studies have revealed many new range extensions, the presence of unsuspected high levels of endemism among some taxa, and taxa new to science. However, many invertebrate groups and the fungi remain poorly known. The vertebrate inventory is fairly complete (Minckley 1973, Miller et al. 1982, Hoffmeister 1986, Brown et al. 1987, and Brennan and Holycross 2006.
Grand Canyon has initiated an All-Taxa Biological Inventory (ATBI). ATBI data are of increasing importance in the region, as human-induced habitat fragmentation and environmental change isolates this World Heritage landscape park from the surrounding, developing terrain, and as species are extirpated in and around the Park. At least 20 species (mostly vertebrates) have been functionally or entirely extirpated from the Park since its establishment in 1919, including most of the large carnivores. Recent inventories have begun to fill some information gaps, but additional ATBI, research, and conservation actions remain outstanding, particularly for species that are rare, cryptic, occupy rare habitats, and the many lesser-known invertebrate taxa. Such information will help the Park fulfill its mandate and provide much new scientific information. In this talk I relate the history of Grand Canyon's biological studies to the newly established ATBI.