@misc{CaoTianAndreevetal.2020, author = {Cao, Xianyong and Tian, Fang and Andreev, Andrei and Anderson, Patricia M. and Lozhkin, Anatoly V. and Bezrukova, Elena and Ni, Jian and Rudaya, Natalia and Stobbe, Astrid and Wieczorek, Mareike and Herzschuh, Ulrike}, title = {A taxonomically harmonized and temporally standardized fossil pollen dataset from Siberia covering the last 40 kyr}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1}, issn = {1866-8372}, doi = {10.25932/publishup-51243}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-512438}, pages = {19}, year = {2020}, abstract = {Pollen records from Siberia are mostly absent in global or Northern Hemisphere synthesis works. Here we present a taxonomically harmonized and temporally standardized pollen dataset that was synthesized using 173 palynological records from Siberia and adjacent areas (northeastern Asia, 42-75 degrees N, 50-180 degrees E). Pollen data were taxonomically harmonized, i.e. the original 437 taxa were assigned to 106 combined pollen taxa. Age-depth models for all records were revised by applying a constant Bayesian age-depth modelling routine. The pollen dataset is available as count data and percentage data in a table format (taxa vs. samples), with age information for each sample. The dataset has relatively few sites covering the last glacial period between 40 and 11.5 ka (calibrated thousands of years before 1950 CE) particularly from the central and western part of the study area. In the Holocene period, the dataset has many sites from most of the area, with the exception of the central part of Siberia. Of the 173 pollen records, 81 \% of pollen counts were downloaded from open databases (GPD, EPD, PANGAEA) and 10 \% were contributions by the original data gatherers, while a few were digitized from publications. Most of the pollen records originate from peatlands (48 \%) and lake sediments (33 \%). Most of the records (83 \%) have >= 3 dates, allowing the establishment of reliable chronologies. The dataset can be used for various purposes, including pollen data mapping (example maps for Larix at selected time slices are shown) as well as quantitative climate and vegetation reconstructions. The datasets for pollen counts and pollen percentages are available at https://doi.org/10.1594/PANGAEA.898616 (Cao et al., 2019a), also including the site information, data source, original publication, dating data, and the plant functional type for each pollen taxa.}, language = {en} } @misc{TianHerzschuhMischkeetal.2014, author = {Tian, Fang and Herzschuh, Ulrike and Mischke, Steffen and Schl{\"u}tz, Frank}, title = {What drives the recent intensified vegetation degradation in Mongolia}, series = {The Holocene}, journal = {The Holocene}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-404201}, pages = {10}, year = {2014}, abstract = {This study examines the course and driving forces of recent vegetation change in the Mongolian steppe. A sediment core covering the last 55years from a small closed-basin lake in central Mongolia was analyzed for its multi-proxy record at annual resolution. Pollen analysis shows that highest abundances of planted Poaceae and highest vegetation diversity occurred during 1977-1992, reflecting agricultural development in the lake area. A decrease in diversity and an increase in Artemisia abundance after 1992 indicate enhanced vegetation degradation in recent times, most probably because of overgrazing and farmland abandonment. Human impact is the main factor for the vegetation degradation within the past decades as revealed by a series of redundancy analyses, while climate change and soil erosion play subordinate roles. High Pediastrum (a green algae) influx, high atomic total organic carbon/total nitrogen (TOC/TN) ratios, abundant coarse detrital grains, and the decrease of C-13(org) and N-15 since about 1977 but particularly after 1992 indicate that abundant terrestrial organic matter and nutrients were transported into the lake and caused lake eutrophication, presumably because of intensified land use. Thus, we infer that the transition to a market economy in Mongolia since the early 1990s not only caused dramatic vegetation degradation but also affected the lake ecosystem through anthropogenic changes in the catchment area.}, language = {en} }