Packrat Midden Evidence of Late Quaternary Vegetation Change in the White Mountains, California-Nevada

Abstract

Packrat (Neotoma spp.) middens from the White Mountains indicate climatic and plant community conditions for the last 19,000 yr. During full-glacial times (ca. 19,000 yr B.P.) and at the Pleistocene/Holocene boundary juniper woodlands were 600 m lower in elevation than at present. Midden assemblages and stable-isotope data suggest lower temperatures and increased precipitation relative to the present into the early Holocene. Two early Holocene middens (ca. 8000 yr B.P.) from lower elevations of the White Mountains contain fragments of pinyon pine and indicate that both pinyon and juniper grew at a site that today supports only a pinyon woodland. Two middle Holocene middens (ca. 5000 yr B.P.) indicate that there was an upward migration of pinyon-juniper woodlands along a high-elevation ecotone, but little change in the middle of the pinyon-juniper woodland. Middens from the late Holocene indicate that present-day plant communities were in place by ca. 2000 yr B.P. or before.

Holocene artiodactyl population histories and large game hunting in the Wyoming Basin, USA

“…In this region, numerous pollen, plant macrofossil, faunal, tree-line movement, hydrological and other records document growing aridity during the early Holocene, a xeric middle Holocene, and a return to more mesic conditions during the late Holocene [47,48,65,74,87,88,103,108,121,125,135,156]. Within this paleoenvironmental context, we next consider how local artiodactyl populations would have responded to variation in the Wyoming Basin moisture regime during the Holocene.…”

Soil Development on Late Pleistocene Moraines at Pine Creek, East-Central Sierra Nevada, California

“…Vegetation at the lower elevations is less productive because of increasing aridity. Packratmidden evidence from the nearby White Mountains and Volcanic Tableland indicate significant environmental and floristic changes in the region during the last 20,000 years (Jennings and Elliott-Fisk, 1993). During Pleistocene cold stages, juniper woodlands were 600 m lower in elevation than at present, suggesting that the moraines at Pine Creek may have supported a woodland until the early Holocene.…”

Lake Tahoe watershed assessment: volume I

“…Evidence of these changes includes the appearance of Utah juniper and singleleaf (piñon) pine around 5500 BP in woodrat middens (nests) from over 10,000 feet in the White Mountains southeast of the Tahoe basin (Jennings and Elliott-Fisk 1993). Semiarid woodland tree species ceased to be present in woodrat middens from lower elevations in the Virginia Mountains northeast of Lake Tahoe, where they are found today (Wigand 1997).…”