Late pleistocene vegetation of kings canyon sierra nevada california usa
Cole, K.
Quaternary Research 19(1): 117-129
1983
ISSN/ISBN: 0033-5894 Accession: 005796120
Seven packrat midden samples make possible a comparison between the modern and late Pleistocene vegetation in Kings Canyon on the western side of the southern Sierra Nevada. One modern sample contains macrofossils and pollen derived from the present-day oak-chaparral vegetation. Macrofossils from the 6 late Pleistocene samples record a mixed coniferous forest dominated by the xerophytic conifers Juniperus occidentalis, Pinus cf. ponderosa and P. monophylla. The pollen spectra of these Pleistocene middens are dominated by Pinus sp., Taxodiaceae-Cupressaceae-Taxaceae (TCT) and Artemisia sp. Mesophytic conifers are represented by low macrofossil concentrations. Sequoiadendron giganteum is presented by a few pollen grains in the full glacial. Edaphic and snow dispersal are the most likely causes of these mixed assemblages. The dominant macrofossils record a more xeric plant community than those that now occur on similar substrates at higher elevations or latitudes in the Sierra Nevada. These assemblages suggest that late Wisconsin climates were cold with mean annual precipitation not necessarily greater than modern values. A model of low summer ablation allowing for the persistence of the glaciers at higher elevations during the late Wisconsin was supported. S. giganteum may have grown at lower elevations along the western side of the range and P. monophylla may have been more widely distributed in cismontane California during the Pleistocene.