LATE QUATERNARY VEGETATION OF THE GRAND CANYON
RECONSTRUCTED FROM FOSSIL PACKRAT MIDDENS
Kenneth L. Cole
NPS - CPSU
115 Green Hall
Department of Forest Resources
University of Minnesota
St. Paul, MN 55108
The late Quaternary vegetation of Grand Canyon National Park was reconstructed using plant macrofossils extracted from radiocarbon dated fossil packrat (Neotoma sp.) middens. During the Wisconsin period, the Grand Canyon supported coniferous woodlands and forests, ranging from an association of juniper, shadscale, and sagebrush below 1400 m, to a mixed coniferous forest of Douglas fir, limber pine, and spruce at higher elevations. During the early Holocene (11,000 to 8500 yr B.P.), these species were replaced by associations of juniper and single leaf ash at low elevations, and by Douglas fir, ponderosa pine, and shrub live oak at high elevations. The modern plant communities developed sometime after 8500 yr B.P.
In general, plant species are now distributed 700 to 900 m higher in elevation and 400 to 700 km further up-river than they were during the late Wisconsin. However, many Wisconsin-age plant assemblages were unique, with their modern analogs either unknown or having a restricted distribution. Similarly, some modern communities either had no analog in the Wisconsin, or they were too restricted in distribution to produce a fossil record.
COMPUTERIZED DATABASE ON GRAND CANYON PALEONTOLOGY
Earle E. Spamer
Academy of Natural Sciences
1900 Benjamin Franklin Parkway
Philadelphia, PA 19103-1195
Well over a thousand species of fossil animals and plants have been reported from Grand Canyon National Park and vicinity. Fossil and sub-fossil remains occur in nearly every rock stratum and in cave deposits, ranging in age from Middle Proterozoic (~1.4 billion years) virtually to the present (but excluding most of the Mesozoic era since these strata have been eroded away from the Grand Canyon). Records of these fossils are scattered through hundreds of papers and monographs, the first having been published in 1861. A database, GCPALEO, has been prepared that provides a page-by-page index to every fossil cited throughout the entire library of Grand Canyon Geology. As well as bibliographical coverage, it includes cross-indexes that encompass all published information on biological systematic groupings, stratigraphic and geographic distributions, and individual specimens held in research collections. GCPALEO now contains more than 17,500 records. It occupies 11.5 MB of uncondensed disk space, but it can be converted to a delimited ASCII-format file of 3.1 MB. Data entry, done directly from books and journal papers that had already been located, took about a year. A bibliography and 39 subject-related indexes to the Grand Canyon paleontological record have been extracted from the database. To obtain the information, the database was queried, and the answer tables were transported into word processing software where they were manipulated to produce a typeset, camera-ready document more than 1,000 pages long. After peer review, it is now in press (Geological Society of America Microform Pub. 24). The database can also provide data on the history of paleontological research in the Grand Canyon region. Comparable productions in other NPS areas with significant paleontological resources would be limited only by the degree of knowledgeable access to the geologic literature, and by pragmatic constraints of staffing and time.