Date of Award
8-17-2023
Document Type
Thesis
Abstract
The regional response of vegetation to global atmospheric circulation patterns and human influence throughout the Holocene is recorded by environmental proxies in sediment cores from Lake Khargal in northern Mongolia. Pollen, spores, total organic carbon, and grain size analysis indicate that conditions in the watershed were moderately humid at ~11500 cal yr B.P. The vegetation community surrounding Lake Khargal consists of mainly of Artemisia (sage), Poaceae (grass), and Betula (birch) with a modest amount of extra-local Pinus (pine) from nearby boreal forests. Fluctuations in the ratios of these and other taxa show that aridity increased after ~10000 cal yr B.P., reaching its maximum at ~7900 cal yr B.P., which coincides with a global cooling event. Regional moisture availability gradually increases after ~7900 cal yr B.P., reaching its peak at ~2100 cal yr B.P., then decreases toward the present. Evidence of regional human activity appears in the taxonomic record around 5500 cal yr B.P. and persists into today.
Recommended Citation
Barna, Joshua A., "An 11,600-year reconstruction of vegetation communities, moisture availability, and land use changes at Lake Khargal, northern Mongolia" (2023). Geosciences . 302.
https://ualaska.researchcommons.org/uaf_grad_geosci/302
Handle
http://hdl.handle.net/11122/14612