TY - JOUR A1 - Cao, Xianyong A1 - Ni, Jian A1 - Herzschuh, Ulrike A1 - Wang, Yongbo A1 - Zhao, Yan T1 - A late quaternary pollen dataset from eastern continental Asia for vegetation and climate reconstructions set up and evaluation JF - Review of palaeobotany and palynology : an international journal N2 - A total of 271 pollen records were selected from a large collection of both raw and digitized pollen spectra from eastern continental Asia (70 degrees-135 degrees E and 18 degrees-55 degrees N). Following pollen percentage recalculations, taxonomic homogenization, and age-depth model revision, the pollen spectra were interpolated at a 500-year resolution and a taxonomically harmonized and temporally standardized fossil pollen dataset established with 226 pollen taxa, covering the last 22 cal lea. Of the 271 pollen records, 85% were published since 1990, with reliable chronologies and high temporal resolutions; of these, 50% have raw data with complete pollen assemblages, ensuring the quality of this dataset The pollen records available for each 500-year time slice are well distributed over all main vegetation types and climatic zones of the study area, making their pollen spectra suitable for paleovegetation and paleoclimate research. Such a dataset can be used as an example for the development of similar datasets for other regions of the world. KW - fossil pollen KW - eastern asia KW - pollen taxa KW - age-depth model KW - resampling Y1 - 2013 U6 - https://doi.org/10.1016/j.revpalbo.2013.02.003 SN - 0034-6667 VL - 194 IS - 13 SP - 21 EP - 37 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tabares Jimenez, Ximena del Carmen A1 - Zimmermann, Heike Hildegard A1 - Dietze, Elisabeth A1 - Ratzmann, Gregor A1 - Belz, Lukas A1 - Vieth-Hillebrand, Andrea A1 - Dupont, Lydie A1 - Wilkes, Heinz A1 - Mapani, Benjamin A1 - Herzschuh, Ulrike T1 - Vegetation state changes in the course of shrub encroachment in an African savanna since about 1850 CE and their potential drivers JF - Ecology and evolution N2 - Shrub encroachment has far-reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning. We document the compositional change and potential drivers for a northern Namibian Combretum woodland transitioning into a Terminalia shrubland. We use a multiproxy record (pollen, sedimentary ancient DNA, biomarkers, compound-specific carbon (delta C-13) and deuterium (delta D) isotopes, bulk carbon isotopes (delta(13)Corg), grain size, geochemical properties) from Lake Otjikoto at high taxonomical and temporal resolution. We provide evidence that state changes in semiarid environments may occur on a scale of one century and that transitions between stable states can span around 80 years and are characterized by a unique vegetation composition. We demonstrate that the current grass/woody ratio is exceptional for the last 170 years, as supported by n-alkane distributions and the delta C-13 and delta(13)Corg records. Comparing vegetation records to environmental proxy data and census data, we infer a complex network of global and local drivers of vegetation change. While our delta D record suggests physiological adaptations of woody species to higher atmospheric pCO(2) concentration and drought, our vegetation records reflect the impact of broad-scale logging for the mining industry, and the macrocharcoal record suggests a decrease in fire activity associated with the intensification of farming. Impact of selective grazing is reflected by changes in abundance and taxonomical composition of grasses and by an increase of nonpalatable and trampling-resistant taxa. In addition, grain-size and spore records suggest changes in the erodibility of soils because of reduced grass cover. Synthesis. We conclude that transitions to an encroached savanna state are supported by gradual environmental changes induced by management strategies, which affected the resilience of savanna ecosystems. In addition, feedback mechanisms that reflect the interplay between management legacies and climate change maintain the encroached state. KW - climate change KW - fossil pollen KW - land-use change KW - savanna ecology KW - sedimentary ancient DNA KW - state and transition KW - tree-grass interactions Y1 - 2019 U6 - https://doi.org/10.1002/ece3.5955 SN - 2045-7758 VL - 10 IS - 2 SP - 962 EP - 979 PB - Wiley CY - Hoboken ER -