TY - JOUR A1 - Zhang, Shengrui A1 - Xu, Qinghai A1 - Gaillard, Marie-Jose A1 - Cao, Xianyong A1 - Li, Jianyong A1 - Zhang, Liyan A1 - Li, Yuecong A1 - Tian, Fang A1 - Zhou, Liping A1 - Lin, Fengyou A1 - Yang, Xiaolan T1 - Characteristic pollen source area and vertical pollen dispersal and deposition in a mixed coniferous and deciduous broad-leaved woodland in the Changbai mountains, northeast China JF - Vegetation History and Archaeobotany N2 - Pollen influx (number of pollen grains cm−2 year−1) can objectively reflect the dispersal and deposition features of pollen within a certain time and space, and is often used as a basis for the quantitative reconstruction of palaeovegetation; however, little is known about the features and mechanisms of vertical dispersal of pollen. Here we present the results from a 5 year (2006–2010) monitoring program using pollen traps placed at different heights from ground level up to 60 m and surface soil samples in a mixed coniferous and deciduous broad-leaved woodland in the Changbai mountains, northeastern China. The pollen percentages and pollen influx from the traps have very similar characteristics to the highest values for Betula, Fraxinus, Quercus and Pinus, among the tree taxa and Artemisia, Chenopodiaceae and Asteraceae among the herb taxa. Pollen influx values vary significantly with height and show major differences between three distinct layers, above-canopy (≥32 m), within the trunk layer (8 ≤ 32 m) and on the ground (0 m). These differences in pollen influx are explained by differences in (i) the air flows in each of these layers and (ii) the fall speed of pollen of the various taxa. We found that the pollen recorded on the ground surface is a good representation of the major part of the pollen transported in the trunk space of the woodland. Comparison of the pollen influx values with the theoretical, calculated “characteristic pollen source area” (CPSA) of 12 selected taxa indicates that the pollen deposited on the ground surface of the woodland is a fair representation with 85–90 % of the total pollen deposited at a wind speed of 2.4 m s−1 coming from within ca. 1–5 km for Pinus and Quercus, ca. 5–10 km for Ulmus, Tilia, Oleaceae and Betula, ca. 20–40 km for Fraxinus, Poaceae, Chenopodiaceae, Populus and Salix, and ca. 30–60 km for Artemisia; it is also a good representation with 90–98 % of the total pollen deposited coming from within 60 km at a wind speed of 2.4 m s−1, or 100 km at a wind speed: 6 m s−1, for the 12 selected taxa used in the CPSA calculation. Furthermore, comparison with the vegetation map of the area around the sampling site shows that the pollen deposited on the ground represents all plant communities which grow in the study area within 70 km radius of the sampling site. In this study, the pollen percentages obtained from the soil surface samples are significantly biased towards pollen taxa with good preservation due to thick and robust pollen walls. Therefore, if mosses are available instead, soil samples should be avoided for pollen studies, in particular for the study of pollen-vegetation relationships, the estimation of pollen productivities and quantitative reconstruction of past vegetation. The results also indicate that the existing model of pollen dispersal and deposition, Prentice’s model, provides a fair description of the actual pollen dispersal and deposition in this kind of woodland, which suggests that the application of the landscape reconstruction algorithm would be relevant for reconstruction of this type of woodland in the past. KW - Changbai mountains KW - Mixed coniferous and deciduous broad-leaved woodland KW - Vertical pollen dispersal and deposition KW - Characteristic pollen source area Y1 - 2016 U6 - https://doi.org/10.1007/s00334-015-0532-0 SN - 0939-6314 SN - 1617-6278 VL - 25 SP - 29 EP - 43 PB - Springer CY - New York ER - TY - JOUR A1 - Marquer, Laurent A1 - Gaillard, Marie-Jose A1 - Sugita, Shinya A1 - Poska, Anneli A1 - Trondman, Anna-Kari A1 - Mazier, Florence A1 - Nielsen, Anne Birgitte A1 - Fyfe, Ralph M. A1 - Jonsson, Anna Maria A1 - Smith, Benjamin A1 - Kaplan, Jed O. A1 - Alenius, Teija A1 - Birks, H. John B. A1 - Bjune, Anne E. A1 - Christiansen, Jorg A1 - Dodson, John A1 - Edwards, Kevin J. A1 - Giesecke, Thomas A1 - Herzschuh, Ulrike A1 - Kangur, Mihkel A1 - Koff, Tiiu A1 - Latalowa, Maligorzata A1 - Lechterbeck, Jutta A1 - Olofsson, Jorgen A1 - Seppa, Heikki T1 - Quantifying the effects of land use and climate on Holocene vegetation in Europe JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming practices and forestry in response to population growth and industrialization. This is a unique signature of anthropogenic impact within the Holocene but European vegetation remains climatically sensitive and thus may continue to respond to ongoing climate change. (C) 2017 Elsevier Ltd. All rights reserved. KW - Climate KW - Holocene KW - Human impact KW - Land use KW - LPJ-GUESS KW - Europe KW - Pollen KW - REVEALS KW - Vegetation composition Y1 - 2017 U6 - https://doi.org/10.1016/j.quascirev.2017.07.001 SN - 0277-3791 VL - 171 SP - 20 EP - 37 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Cao, Xianyong A1 - Tian, Fang A1 - Li, Furong A1 - Gaillard, Marie-Jose A1 - Rudaya, Natalia A1 - Xu, Qinghai A1 - Herzschuh, Ulrike T1 - Pollen-based quantitative land-cover reconstruction for northern Asia covering the last 40 ka cal BP JF - Climate of the past : an interactive open access journal of the European Geosciences Union N2 - We collected the available relative pollen productivity estimates (PPEs) for 27 major pollen taxa from Eurasia and applied them to estimate plant abundances during the last 40 ka cal BP (calibrated thousand years before present) using pollen counts from 203 fossil pollen records in northern Asia (north of 40 degrees N). These pollen records were organized into 42 site groups and regional mean plant abundances calculated using the REVEALS (Regional Estimates of Vegetation Abundance from Large Sites) model. Time-series clustering, constrained hierarchical clustering, and detrended canonical correspondence analysis were performed to investigate the regional pattern, time, and strength of vegetation changes, respectively. Reconstructed regional plant functional type (PFT) components for each site group are generally consistent with modern vegetation in that vegetation changes within the regions are characterized by minor changes in the abundance of PFTs rather than by an increase in new PFTs, particularly during the Holocene. We argue that pollen-based REVEALS estimates of plant abundances should be a more reliable reflection of the vegetation as pollen may overestimate the turnover, particularly when a high pollen producer invades areas dominated by low pollen producers. Comparisons with vegetation-independent climate records show that climate change is the primary factor driving land-cover changes at broad spatial and temporal scales. Vegetation changes in certain regions or periods, however, could not be explained by direct climate change, e.g. inland Siberia, where a sharp increase in evergreen conifer tree abundance occurred at ca. 7-8 ka cal BP despite an unchanging climate, potentially reflecting their response to complex climate-permafrost-fire-vegetation interactions and thus a possible long-term lagged climate response. Y1 - 2019 U6 - https://doi.org/10.5194/cp-15-1503-2019 SN - 1814-9324 SN - 1814-9332 VL - 15 IS - 4 SP - 1503 EP - 1536 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Marquer, Laurent A1 - Gaillard, Marie-Jose A1 - Sugita, Shinya A1 - Trondman, Anna-Kari A1 - Mazier, Florence A1 - Nielsen, Anne Birgitte A1 - Fyfe, Ralph M. A1 - Odgaard, Bent Vad A1 - Alenius, Teija A1 - Birks, H. John B. A1 - Bjune, Anne E. A1 - Christiansen, Jörg A1 - Dodson, John A1 - Edwards, Kevin J. A1 - Giesecke, Thomas A1 - Herzschuh, Ulrike A1 - Kangur, Mihkel A1 - Lorenz, Sebastian A1 - Poska, Anneli A1 - Schult, Manuela A1 - Seppa, Heikki T1 - Holocene changes in vegetation composition in northern Europe: why quantitative pollen-based vegetation reconstructions matter JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - We present pollen-based reconstructions of the spatio-temporal dynamics of northern European regional vegetation abundance through the Holocene. We apply the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using fossil pollen records from eighteen sites within five modern biomes in the region. The eighteen sites are classified into four time-trajectory types on the basis of principal components analysis of both the REVEALS-based vegetation estimates (RVs) and the pollen percentage (PPs). The four trajectory types are more clearly separated for RVs than PPs. Further, the timing of major Holocene shifts, rates of compositional change, and diversity indices (turnover and evenness) differ between RVs and PPs. The differences are due to the reduction by REVEALS of biases in fossil pollen assemblages caused by different basin size, and inter-taxonomic differences in pollen productivity and dispersal properties. For example, in comparison to the PPs, the RVs show an earlier increase in Corylus and Ulmus in the early-Holocene and a more pronounced increase in grassland and deforested areas since the mid-Holocene. The results suggest that the influence of deforestation and agricultural activities on plant composition and abundance from Neolithic times was stronger than previously inferred from PPs. Relative to PPs, RVs show a more rapid compositional change, a largest decrease in turnover, and less variable evenness in most of northern Europe since 5200 cal yr BP. All these changes are primarily related to the strong impact of human activities on the vegetation. This study demonstrates that RV-based estimates of diversity indices, timing of shifts, and rates of change in reconstructed vegetation provide new insights into the timing and magnitude of major human distribution on Holocene regional, vegetation, feature that are critical in the assessment of human impact on vegetation, land-cover, biodiversity, and climate in the past. KW - Holocene KW - Human impact KW - Northern Europe KW - Pollen KW - Quantitative regional plant abundance KW - Rate of compositional change KW - REVEALS (Regional Estimates of VEgetation KW - Abundance from Large Sites) model KW - Vegetation diversity indices Y1 - 2014 U6 - https://doi.org/10.1016/j.quascirev.2014.02.013 SN - 0277-3791 VL - 90 SP - 199 EP - 216 PB - Elsevier CY - Oxford ER -