ALBERT

Description: This dataset corresponds to the pollen-based REVEALS estimates of 25 plant taxa for Europe and associated standard errors, published in Marquer et al. (2017). This is part of the results from the Swedish project LandClim I (Gaillard et al., 2010; Trondman et al., 2015; Marquer et al., 2014, 2017). The study area includes a large part of northern and Central Europe, i.e. Ireland, Great Britain and a latitudinal transect from the Alps in the south to northernmost Norway. These REVEALS estimates are based on 151 pollen records (small/large, lakes/bogs/mires) that were selected from the European Pollen Database (Fyfe et al., 2009; Giesecke et al., 2014), the Alpine Palynological Data-Base (University of Bern, Switzerland), or were provided directly by individual data contributors. The selected pollen records are grouped into 36 1° x 1° grid-cells. Twenty-five consecutive time windows over the last 11,700 years BP are used: 0-100, 100-350, 350-700 BP for the three first time windows, and 500 calendar years each from 700 to 11,700 BP. For details about the REVEALS model, see Sugita (2007). In the excel file, the folder "Metadata" contains the explanation of abbreviations in the data folders and information about the pollen records used for the REVEALS reconstructions. All REVEALS estimates and their SEs are given in proportions of the grid cell (the total of all REVEALS estimates sum up to 1). The codes of the 25 consecutive time windows are given in the folder "Code time windows". The results of the 36 grid cells are in the folder "REVEALS 36GCs" and the related standard errors in the folder "SE_REVEALS 36GCs". Note that in the folder "Metadata", the GPS coordinates correspond to the upper left (NW) corners of each grid cell.

Description: Fossil pollen assemblages provide a record of past vegetation composition, both natural (climate-induced) and anthropogenic (human-induced). Pollen-based quantitative reconstruction of plant abundance (in percentage cover) require that biases due to differences between plants in pollen productivity and dispersal characteristics are corrected. Such correction is achieved by the “Regional Estimates of VEgetation Abundance from Large Sites”(REVEALS) model given that estimates of relative pollen productivity (RPPs) and fall speed of pollen (FSP) are available for the major plants building the plant cover. For details about the REVEALS model, see Sugita (2007). REVEALS estimates of the abundance of 31 taxa, 11 plant functional types (PFTs), and 3 land-cover types (LCTs) were produced for Europe at a 1˚x1˚ spatial scale for 25 consecutive time windows from 11.7 ka calibrated years BP* to present as part of the Swedish Research Council (VR) research project “LandClimII”. This is the second generation (version June 2021) of REVEALS reconstruction for Europe; it is based on a total of 1128 pollen records from pollen databases/archives and individual authors (See LandClimII Contributors). The first generation was published in Trondman et al. (2015) and Gaillard (2019). These pollen-based REVEALS estimates of land cover are currently used to quantify the effects of the biogeophysical forcing induced by human deforestation on the regional climate of Europe at 6 ka and 2.5 ka BP (VR LandClim II project), and to evaluate and revise the scenarios of anthropogenic land-cover change (ALCC) HYDE (Klein Goldewijk et al., 2017) and KK10 (Kaplan et al., 2009; 2011) . The gridded pollen-based REVEALS reconstructions cover Europe (30°-75°N, 25°W-50°E) and were performed at a spatial scale of 1° × 1° (ca. 100 km × 100 km), which is the estimated spatial scale of REVEALS plant-cover estimates using all available pollen records (1128) within a grid cell and all pollen counts within each time window to ensure reliable estimates of plant cover and minimize their error estimates. The REVEALS estimates and standard errors were reconstructed for 25 time windows covering the Holocene i.e. X to 100 BP, 100 – 350 BP, 350 – 700, 700 – 1200, 1200 -1700 BP and in 500 consecutive time windows from here to 11,700 BP (BP – before present (1950)). The RPP and FSP values used in this REVEALS reconstruction are found in csv table Taxa_to_PFT, PPE and FSP values. All details of the protocol used for this REVEALS reconstruction can be found in Trondman et al. (2015). All REVEALS estimates and their SEs are given in proportions of the grid cell (the total of all REVEALS estimates sum up to 1). There are 25 files labelled TW.(number of time window).RVestimates.jun21.csv and 25 files labelled TW.(number of time window).standarderrors.jun21.csv. The RVestimates.csv files contain the REVEALS estimates for each land-cover type (LCT), plant function type (PFT) and taxa which has a unique grid ID and corresponding longitude and latitude. The standard error csv files contain the standard errors for each land-cover type (LCT), plant function type (PFT) and taxa. * BP = before present (1950). The information about the quality (previously referred to as reliability (Trondman et al. 2015)) of the REVEALS estimates in each grid cell is provided in the GC_quality_by_TW.xlsx file. There are 3 categories i.e. 1 is high quality ( 1 or more large lakes, OR 2 or more sites of any site type), 2 is low quality (only 1 small lake, OR small bog OR large bog) and no data. Extra information about each site is provided in the metadata file.

Description: Fossil pollen assemblages provide a record of past vegetation composition, both natural (climate-induced) and anthropogenic (human-induced). Pollen-based quantitative reconstruction of plant abundance (in percentage cover) require that biases due to differences between plants in pollen productivity and dispersal characteristics are corrected. Such correction is achieved by the “Regional Estimates of VEgetation Abundance from Large Sites”(REVEALS) model given that estimates of relative pollen productivity (RPPs) and fall speed of pollen (FSP) are available for the major plants building the plant cover. For details about the REVEALS model, see Sugita (2007). REVEALS estimates of the abundance of 31 taxa, 11 plant functional types (PFTs), and 3 land-cover types (LCTs) were produced for Europe at a 1˚x1˚ spatial scale for 25 consecutive time windows from 11.7 ka calibrated years BP* to present as part of the Swedish Research Council (VR) research project “LandClimII”. This is the second generation (version October 2020) of REVEALS reconstruction for Europe; it is based on a total of 1128 pollen records from pollen databases/archives and individual authors (See LandClimII Contributors). The first generation was published in Trondman et al. (2015) and Gaillard (2019). These pollen-based REVEALS estimates of land cover are currently used to quantify the effects of the biogeophysical forcing induced by human deforestation on the regional climate of Europe at 6 ka and 2.5 ka BP (VR LandClim II project), and to evaluate and revise the scenarios of anthropogenic land-cover change (ALCC) HYDE (Klein Goldewijk et al., 2017) and KK10 (Kaplan et al., 2009; 2011) . The gridded pollen-based REVEALS reconstructions cover Europe (30°-75°N, 25°W-50°E) and were performed at a spatial scale of 1° × 1° (ca. 100 km × 100 km), which is the estimated spatial scale of REVEALS plant-cover estimates using all available pollen records (1128) within a grid cell and all pollen counts within each time window to ensure reliable estimates of plant cover and minimize their error estimates. The REVEALS estimates and standard errors were reconstructed for 25 time windows covering the Holocene i.e. X to 100 BP, 100 – 350 BP, 350 – 700, 700 – 1200, 1200 -1700 BP and in 500 consecutive time windows from here to 11,700 BP (BP – before present (1950)). The RPP and FSP values used in this REVEALS reconstruction are found in csv table called Taxa_to_PFT, PPE and FSP values. All details of the protocol used for this REVEALS reconstruction can be found in Trondman et al. (2015). All REVEALS estimates and their SEs are given in proportions of the grid cell (the total of all REVEALS estimates sum up to 1). There are 25 files labelled TW.(number of time window).RVestimates.csv and 25 files labelled TW.(number of time window).standarderrors.csv. The RVestimates.csv files contain the REVEALS estimates for each land-cover type (LCT), plant function type (PFT) and taxa which has a unique grid ID and corresponding longitude and latitude. The standard error csv files contain the standard errors for each land-cover type (LCT), plant function type (PFT) and taxa. BP = before present (1950)

Description: We present the first gridded and temporally continuous quantitative pollen-based plant-cover reconstruction for temperate and northern subtropical China over the Holocene (11.7 ka to present) obtained by applying the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model. The objective is to provide a dataset of pollen-based land cover for the last ca. 12 millennia that is suitable for palaeoclimate modelling and for the evaluation of simulated past vegetation cover from dynamic vegetation models and anthropogenic land-cover change (ALCC) scenarios. The REVEALS reconstruction was achieved using 94 selected pollen records from lakes and bogs at a 1× 1 spatial scale and a temporal resolution of 500 years between 11.7 and 0.7 ka and in three recent time windows (0.7-0.35 ka, 0.35-0.1 ka, and 0.1 ka to present). The dataset includes REVEALS estimates of cover and their standard errors (SEs) for 27 plant taxa in 75 1 × 1 grid cells distributed within the study region. The 27 plant taxa were also grouped into 6 plant functional types and 3 land-cover types (coniferous trees CT, broadleaved trees BT, and C3 herbs/open land (C3H/OL)), and their REVEALS estimates of cover and related SEs were calculated. We describe the protocol used for the selection of pollen records and the REVEALS application (with parameter settings) and explain the major rationales behind the protocol. As an illustration, we present, for eight selected time windows, gridded maps of the pollen-based REVEALS estimates of cover for the three land-cover types (CT, BT, and C3H/OL). We then discuss the reliability and limitations of the Chinese dataset of Holocene gridded REVEALS plant cover, and its current and potential uses. The dataset is available at the National Tibetan Plateau Data Center (TPDC; Li, 2022; 10.11888/Paleoenv.tpdc.272292).

Description: We present the first step to quantitatively reconstruct vegetation cover in central Europe. Modern vegetation and pollen deposition were compared for 20 small to medium sized lakes and their catchments on the Swiss Plateau, a relatively flat region between the Jura Mountains and the Alps. To correct for the pollen dispersal bias in pollen assemblages, vegetation abundance was distance-weighted using three different approaches. The Relevant Source Area of Pollen (RSAP) and pollen productivity of 13 plant taxa were estimated using three different submodels of the Extended R-Value model (ERV-model). RSAP was 800 m regardless of the applied distance-weighting or ERV submodel. Pollen Productivity Estimates (PPE) varied from 10 to 〈 0.1 among pollen taxa and differed slightly between the models. Relative to grasses most trees were higher pollen producers and some were equal producers, whereas the herb taxa showed lower PPE. Generally, PPE from lowland Switzerland differ from those found in other European regions. Sampling strategies of vegetation and pollen samples are a likely cause for this variation. However, pollen productivity is also influenced by regionally different factors, such as climate, vegetation structure, geology and soil types. In addition, differences at genus or species level may occur between areas. Our comparison between the different regions in Europe shows that PPE of one region may not be directly applicable to other regions.