The data sets contains the content of fungal spores and (Ce+Fa/Po+Fa) ratio data from Gonghai Lake (38°54′N, 112°14′E, altitude 1860 m) in northern China over the past ~2000 years. We calculated pollen (Ce+Fa/Po+Fa) ratio of 321 samples and we identified the fungal spores of 216 sedimentary samples to reconstruct changes in cultivation and grazing intensity over the past ~2,000 years in northern China. Time-series analysis reveals that the arable farming phases had a longer periodicity than the grazing phases, possibly because of the greater resilience of the former to climate change and the attachment of agriculturalists to their land. Our findings potentially help improve our understanding of the impact of land use on soil degradation. The data is stored in Excel format.
HUANG Xiaozhong, ZHANG Jun
Focusing on the "Holocene temperature problem", the Holocene earth temperature change has become a hot issue in the past climate change research. Based on the fossil sporopollen of Xingyun Lake in Yunnan Province, the newly developed method of quantitative reconstruction significance test based on random data is used to quantitatively reconstruct the summer temperature (average temperature in July) in the study area since the past 14000 years. It is found that there is a difference in the change trend between it and the summer precipitation records based on carbon, acid and oxygen isotopes of sediments in the lake, which is mainly reflected in the uncoupled change of the two in the early Holocene, The early Holocene had higher summer precipitation, but lower summer temperature. The author further puts forward that the internal feedback of the earth system dominated by clouds, aerosols and high latitude ice sheet boundary conditions in the northern hemisphere is the main reason for the uncoupling of early Holocene summer precipitation and temperature in Southwest China.
WU Duo
Past vegetation and climate investigations using the pollen assemblages archived in various sediments have been performed for more than one century, hitherto, pollen is the most suitable proxy in reconstruction for the spatial-temporal patterns of past vegetation and climate at centennial- and global-scale, and a taxonomically harmonized and temporally standardized fossil pollen dataset is essential for these reconstructions. Following pollen data collection, taxonomic homogenization, and age–depth model revision, the pollen spectra were interpolated at a 100-year resolution, and the Holocene fossil pollen dataset was established for China. The Holocene pollen dataset includes 254 pollen spectra and 217 pollen taxa. Although the density of available pollen records is higher in the forest-steppe transition-zone, available pollen records are well distributed over all main vegetation types and climatic zones of China. The temporal range of the dataset covers the Holocene (from 11.5 to 0 cal. ka BP), with abundant pollen sites available between 8 and 2 cal ka BP. The Holocene pollen dataset is relative to the literature: Cao, X., Tian, F., Herzschuh, U., Ni, J., Xu, Q., Li, W., Zhang, Y., Luo, M., Chen, F., 2022. Human activities have reduced plant diversity in eastern China over the last two millennia, Global Change Biology (accepted). More detail on processing is provided in this literature.
CAO Xianyong, TIAN Fang, NI Jian, HERZSCHUH Ulrike
Modern pollen dataset is essential for investigating the relationships between pollen and vegetation and climate, and for the pollen-based past vegetation and climate quantitative reconstructions. Asia has various landform types, climate systems and vegetation types, however, researches on pollen modern processes in Asia are generally restricted at regional scale, hitherto, an entire modern pollen dataset absent in Asia. Based on previous pollen data collection and modern pollen analysis (for special regions), authors have established a modern pollen dataset for Asia initially. The modern pollen dataset including 9165 sampling sites with 245 pollen taxa (at genus and family level), covering evenly the most of parts of Asia. This modern pollen dataset can be utilized in pollen-based past vegetation and climate reconstructions at board spatial-scale, and in reliability assessing for vegetation and climate models. The modern pollen dataset is relative to the literature: Cao, X., Tian, F., Herzschuh, U., Ni, J., Xu, Q., Li, W., Zhang, Y., Luo, M., Chen, F., 2022. Human activities have reduced plant diversity in eastern China over the last two millennia, Global Change Biology (accepted). More detail on processing is provided in this literature.
CAO Xianyong, TIAN Fang, XU Qinghai , NI Jian, HERZSCHUH Ulrike
Understanding the modern relationships between pollen and vegetation, climate, and human land-use completely, is essential for quantitative reconstructions of past vegetation, climate and human impacts. supported by the Second Tibetan Plateau Scientific Expedition Program, we have collected more than 700 surface-soil samples together with detail vegetation survey. Hitherto, pollen analysis of 318 samples have been completed, and the submitted modern pollen dataset includes the pollen percentages of 24 common taxa, the sampling sites of the dataset cover the all vegetation types on the east and central Tibetan Plateau. The dataset can be utilized in establishment for pollen-climate, pollen-vegetation calibration-sets.
CAO Xianyong
The Regional Estimates of Vegetation Abundance from Large Sites (REVEALS) model was developed by Sugita (2007) to correct for bias due to inter-taxonomic differences in pollen productivity and dispersion and estimate plant cover at a regional spatial scale based on pollen records. We provide the dataset of pollen-based REVEALS reconstruction for temperate and northern sub-tropical China over the Holocene. The REVEALS reconstruction was achieved using 94 selected pollen records from lakes and bogs at a 1˚x1˚ spatial scale and a temporal resolution of 500 years between 11.7 and 0.7 ka BP, and three recent time windows (0.7˗0.35 ka BP, 0.35˗0.1 ka BP, and 0.1 ka BP˗present). The dataset of pollen-based REVEALS reconstruction of Holocene plant cover for the study region includes the REVEALS proportions of plant cover (and related SEs) for 75 1˚x 1˚grid cells and 25 time windows for each grid cell for 27 taxa, two alternatives of aggregation of plant taxa to PFTs: ten PFTs and six PFTs, and three land-cover types. The metadata files providing details on the sites used in the REVEALS reconstruction for each grid cell and each time window. For instance, the original site names, modern vegetation zones, geographical coordinates (latitude and longitude in decimal degrees), elevation in meters above sea level, site types (bog or lake), basin sizes (radius and area), number of 14C radiocarbon dates or other types of dates, approximate temporal extent of the site. The dataset is suitable for palaeoclimate modeling, can be applied also in evaluating simulations of past vegetation from dynamic vegetation models and anthropogenic land cover change (ALCC) scenarios.
LI Furong
Relationship between modern pollen and climate, and its representative to vegetation are the important references in explaining and reconstructing past climate and vegetation qualitatively or quantitatively. To extrct past climate and vegetation signals from fossil pollen spectrum of a lacustrine sediment, a corresponding modern pollen dataset collected from lake-sediment surface is necessary. At present, there are a few modern pollen datasets extracted from lake sediment-surface established on the Tibetan Plateau, however, the geographic gaps (e.g. the central and east Tibetan Plateau) of available sampled lakes influence the correct understanding. To ensure the even distribution of the representative lakes, we collected lake sediment-surface samples (n=117) covering the alpine meadow evenly on the east and central Tibetan Plateau, in July and August 2018. For pollen extraction, approximately 10 g (wet original sediment) per sample were sub-sampled. Pollen sample was processed by the standard acid-alkali-acid procedures followed by 7-μm-mesh sieving. More than 500 terrestrial pollen grains were counted for each sample. Pollen assemblages of the dataset from alpine meadow are dominated by Cyperaceae (mean is 68.4%, maximum is 95.9%), with other herbaceous pollen taxa as commen taxa including Poaceae (mean is 10.3%, maximum is 87.7%), Ranunculaceae (mean is 4.8%, maximum is 33.6%), Artemisia (mean is 3.7%, maximum is 24.5%), Asteraceae (mean is 2.1%, maximum is 33.6%), etc. Salix (mean is 0.4%, maximum is 5.3%) is the major shrub taxon in these pollen assemblages, while arboreal taxa occur with low percentages generally (mean of total arboreal percentages is 0.9% (maximum is 5.8%), including mainly Pinus (mean is 0.3%, maximum is 1.8%), Betula (mean is 0.1%, maximum is 0.9%) and Alnus (mean is 0.1%, maximum is 0.7%). These pollen assemblages represent the plant components well in the alpine meadow communities, although they are influenced slightly by long-distance pollen grain transported by wind or river (such as these arboreal pollen taxa). Together with pollen counts and percentages, we also provided the modern climatic data for the sampled lakes. The China Meteorological Forcing Dataset (CMFD; gridded near-surface meteorological dataset) with a temporal resolution of three hours and a spatial resolution of 0.1° was employed, and the climatic data of the nearest pixel of one sampled lake was defined to represent climatic conditions of the lake. Finally, the mean annual precipitation (Pann), mean annual temperature (Tann) and mean temperature of the coldest month (Mtco) and warmest month (Mtwa) are calculated for each sampled lake.
CAO Xianyong, TIAN Fang, LI Kai, NI Jian
This data is the relevant data of biogeochemistry and stable isotope geochemistry of Qaidam Basin. This set of data is mainly based on the research means of paleontology, sedimentary strata and biogeochemistry of typical sections to explore the sedimentary, climatic and biological response of Qaidam basin to the uplift of Qinghai Tibet Plateau in Cenozoic. The data of paleontological isotope and oxygen isotope of the Dachaigou basin are the main biomarkers for the study of Paleontology in the Dachaigou basin. The preliminary research processing results show that the data quality is high
YUAN Feng
This dataset is the biome change data of the Tibetan Plateau since the last glacial maximum which was reconstructed by using a new method. Firstly, a random forest algorithm was applied to establish a pollen-biome classification model for reconstructing past vegetation changes of the Tibetan Plateau, and 1802 modern pollen assemblages from 17 vegetation zones in and around the Tibetan Plateau were used as the training set for the model development. The random forest model showed a reliable performance (accuracy > 76%) in predicting modern biomes from modern pollen assemblages based on a comparison with the observed biomes. Moreover, the random forest model had a significantly higher accuracy than the traditional biomization method. Then, the newly established random forest model is applied to the paleovegetation reconstruction of 51 fossil pollen sequences of the Tibetan Plateau. New age-depth models were developed for these fossil pollen records using the Bayesian method, and all fossil pollen records were linearly interpolated to 500-year time slices. Finally, the spatiotemporal changes of biomes on the Tibetan plateau over the past 22,000 years at an interval of 500 years were reconstructed by using the random forest model. This dataset can provide evidence for understanding the past variation of alpine vegetation and its mechanism; provide the basis for studying the impact of past climate change on vegetation on the Tibetan Plateau; and provide boundary conditions for climate simulation.
QIN Feng , ZHAO Yan, CAO Xianyong
The present data are chronological and palynological data from the Luanhaizi Lake core in the Menyuan Basin, northeastern Tibetan Plateau. We used the AMS14C method to test nine dated samples from the LHZ18 core. Bulk samples were collected from plant remains and organic-rich horizons from the core LHZ18 for accelerator mass spectrometry (AMS)14C dating. Samples were measured at Beta Labs in the USA and Lanzhou University.Pollen analysis was completed at the Key Laboratory of Western China’s Environment Systems,Ministry of Education, Lanzhou University, with 140 stratigraphic pollen samples and 10 topsoil pollen samples. Spore pollen identification statistics were carried out under a light microscope.The pollen results mainly include the number of grains of trees, shrubs, herbs and aquatic plants.
HUANG Xiaozhong, ZHANG Jun, WANG Tao
A 170-cm-long sediment core was extracted from Lake Xingxinghai at a water depth of 9 m (34°50.44′N, 98°06.34′E) in January 2010 using Austria’s UWITEC platform coring equipment. Both the 210Pb/137Cs and AMS 14C (11 dating data) approaches were applicated into the age-depth model establishment using Bayesian age–depth modelling by the “Bacon” software, and the age-depth model indicates the core covers the past 7400 years. The core was sliced at 0.5-cm interval upper 3 cm and 1-cm interval for other part, finally we got 173 samples totally. Pollen grains were extracted using a procedure including the treatments with 10 % HCl, 10 % NaOH and 40 % HF, followed by a 7-μm mesh sieving and acetolysis treatment (9:1 mixture of acetic anhydride and sulfuric acid). Pollen grains were identified and counted under optical microscope, and at least 300 terrestrial pollen grains were counted for each sample. The mean temporal resolution of pollen spectra is ca. 40 year/sample. The pollen spectra include forty-eight pollen taxa, are dominated by herbaceous taxa (range: 88.5~98.9%; mean: 93.4%), such as Artemisia (up to 54.4%), Cyperaceae (up to 50.1%), Poaceae (up to 48.8%), Chenopodiaceae (up to 17.9%) and Asteraceae (up to 8.5%). Abundance of arboreal pollen is less than 5% through out the core, mainly comprised of Pinus (maximum: 4.9%; mean:1.2%) and Betula (maximum: 3.0%; mean: 0.7%). The pollen dataset includes pollen percentages for the 43 terrestrial pollen taxa together with their depths and ages, and the dataset is valuable to employed in past vegetation and climate reconstructions.
TIAN Fang, CAO Xianyong
This data set comes from papers: Cui, A.N., Lu, H.Y., Liu, x.q., Shen, C.M., Xu, D.K., Xu, b.q., Wu, n.q., 2021. Tibetan Plateau precision modulated by the periodically coupled western and Asian Mongolia. Geophysical research letters, 48, Based on the advantage of accurate dating of the annual laminar sediments of the lake Kusai in the northern Tibetan Plateau, the authors analyzed the changes of plant sporopollen species in the area around the lake Kusai in the past 1656 years (350-2006) with high resolution (~ 5-year resolution), Based on 735 representative soil sporopollen assemblages and meteorological interpolation data within 800 km of Lake Kusai and its surrounding areas, a high-precision sporopollen annual precipitation conversion function was established to quantitatively reconstruct the precipitation and annual mean temperature changes in the past 1656 years. This data set provides a reference for studying the past climate change law and predicting the future climate change trend of the Qinghai Tibet Plateau.
LV Houyuan
The data set includes the characteristics of ancient glacial sediments, such as grain size characteristics, sporopollen characteristics, environmental indicators of chemical elements, mineral characteristics of sediments, etc. Table 1 shows the analysis of five samples collected from the red moraine of Q2, which shows that the grain size characteristics of different ages are the difference of grain size distribution caused by weathering strength. The earlier the moraine is formed, the farther the grain size characteristics of the moraine are from the typical moraine facies. According to Tang Lingyu's (1984) analysis of spores and pollen in lignite (Table 2), there are many clouds and firs, but there are many warm loving Castanea, Liquidambar and Quercus, which indicates that the mountain is dark coniferous cold temperate to warm temperate vegetation, while the piedmont plain is warm temperate or even mountain subtropical vegetation, and its altitude is not very high. The sporopollen analysis data of four surface soil samples and Q31 and q32 moraine samples from high to low altitude on the east slope of Gongga mountain show that the SPOROPOLLEN ASSEMBLAGES OF Q31 and q32 moraines are not significantly different from those at present (tables 3 and 4). The chemical elements of moraine samples were analyzed by icpq plasma analyzer. The results show that the other 18 elements can reflect the weathering degree in different degrees except Fe2O3, which is too influenced by local lithology to retrieve the information of age and weathering degree. There are 28 fine-grained samples, and the results are summarized in the table below. The analysis results of Hengduanshan moraine samples are shown in Table 6. It can be seen that there is little difference in the most stable mineral content of the Moraine in different periods. The mineral characteristics of the Moraine in this area clearly reflect the relationship between it and weathering time. It is hoped that through the geochemical study of the temporal and spatial sequence of glacial deposits, the indicator of element migration can be established for the study of Quaternary glacial environment in China.
LI Jijun
In July 2017, our team carried out field vegetation quadrat survey and livestock manure sample collection in Henan and Zeku counties. Random sampling 100 m × 5 ~ 10 pieces of unweathered excrement of the same grazing livestock in 100 m area were mixed into a sample and sealed for preservation. A total of 49 livestock manure samples were collected, including 30 yak (bosgrunniens), 11 horse (Equus ferus cabellus) and 8 sheep (Ovis aries). GPS was used to locate each sampling point, and the vegetation community and main vegetation types within the sampling point were recorded. The dry weight of each sample was 2 g. before sample treatment, 1 Lycopodium spore (27637) was added to each sample ± 563 grains per tablet were used to calculate the sporopollen concentration. Remove the calcareous cement with 10% HCl, after 200 μ The larger particle size of plant residues was removed by M sieve, and the organic matter was removed by 10% KOH in water bath at 70 ℃; Then 40% HF was added to remove the silicate. Finally, 7 μ The sporopollen was enriched by nylon sieve, cleaned and preserved in glycerin. The identification of sporopollen was carried out under 400 times optical biological microscope with reference to the sporopollen morphological atlas and literature. Tilia software was used to draw the sporopollen percentage map. The principal component analysis of sporopollen data was carried out by using canoco5.0 software. This data not only provides new research ideas and means for evaluating grazing livestock feeding habits and the impact of animal husbandry activities on regional vegetation in the Qinghai Tibet Plateau, but also provides important modern process basis and reference data for carrying out pollen analysis of fecal samples preserved in archaeological sites in the Qinghai Tibet Plateau in the future, so as to reconstruct the information of ancient vegetation communities and ancient human production activities.
HOU Guangliang
This dataset is derived from the paper: Tang, H. et al. (2020). Early Oligocene vegetation and climate of southwestern China inferred from palynology. Palaeogeography, Palaeoclimatology, Palaeoecology, 560, 109988. doi:10.1016/j.palaeo.2020.109988 This data is part of Supplementary data of the paper, maily contains: Supplementary table 1) Pollen percentages, which were calculated using the collected pollen samples. Supplementary table 2) Plant functional types (PFTs) for the reconstructed paleovegetation of three sites : Wenshan (Early Oligocene), Jianchuan (Early Oligocene) and Lühe (Late Eocene). Recently, in the town of Lühe, central Yunnan, SW China, a new fossil-bearing section was found and dated as early Oligocene (~33–32 Ma) according to U-Pb isotope of volcanic tuff. The fossil-bearing section totals about 18 m in thickness. Fifty-five pollen samples were collected vertically throughout this Lühe town section. For each sample, 2–2.5 g of sediment were treated with KOH (10%,) HCl (10%) and HF (39%), then sample residues were sieved through a 5 μm nylon mesh in an ultrasonic tank. Spore and pollen grains were identified using both a light microscope (LM, Leica DM1000 microscope) and a scanning electronic microscope (SEM). Single grains were picked up by a capillary tube and then transferred to a copper stub, coated with gold and observed with a Zeiss EVO LS10 SEM. At least 300 pollen grains were counted for each sample under the LM at ×400 magnification. Then the pollen percentages were calculated using the sum of total terrestrial pollen. The paleovegetation was reconstructed following the method described by Prentice et al., 1996, Prentice and Jolly, 2000 and Ni et al. (2010). The paleobiomes were reconstructed by comparing the similarity of the palaeoflora with modern plant functional types (PFTs), according to the data published by Ni et al. (2010). The similarity between the palaeoflora and modern PFTs data was explored using Euclidean distances (Prentice et al., 1996) and the Jaccard Index Coefficient (Pound and Salzmann, 2017). The Jaccard Index Coefficient in the R package “clusteval” was used here to calculate the similarity. The palaeoflora was assigned to the biome with the highest similarity scores, taking into account dominant or key taxa.
TANG He
We have completed the pollen analyses of 252 sedimentary samples from Dahonggou section in Qaidam Basin covering the Cenozoic. Palynomorph extraction followed the routine process with HCl and HF treatments during the extraction. Airborne pollen-charcoal traps and surface-sediment samples from soils were collected to evaluate the relationship between pollen-charcoal contents and vegetation structure, and effect of sedimentary environment conditions on the pollen dispersal and deposition. Combined with pollen-charcoal data from other sections, we are going to establish the fire history spanning the last 30 Ma years, and to discuss the responds and feedbacks of the vegetation and fire to the climate changes. Our work is beneficial to the knowledge of the processes of aridification in Inner Asia and its mechanism. The submitted pollen data set is according to the proposal, and in order to guarantee data accuracy, 20% of the data have been examined in our lab by random sampling method. Data collection and analysis are continued, we hope our work can contribute more to the project in the next few years.
MIAO Yunfa
The modern sporopollen identification results of five different geomorphic types in the middle reaches of Heihe River show that there are 39 sporopollen types, 22 main types, belonging to 6 different vegetation types in 45 topsoil samples distributed in the desert vegetation belt. The SPOROPOLLEN ASSEMBLAGES with high percentage of sporopollen in the sporopollen map were selected to represent different geomorphic types. It was found that five geomorphic types (dune, alluvial proluvial fan, flood plain, riverbed and wetland) could be expressed by different combinations of nine sporopollen.
HU Xiaofei, PAN Baotian
Since the formation of Heihe River, sporopollen data samples have been collected from the drilling strata of Da'ao well in the middle reaches of Heihe River. Drilling location: 39.491 n, 99.605 E. The drilling depth is 140 meters. 128 samples of sporopollen are collected from top to bottom. At present, there are 19 data of sporopollen results, which are distributed in each sedimentary facies from top to bottom. The sporopollen samples were removed from carbonate, organic matter, silicate and other impurities in the laboratory, and the species and data of sporopollen were identified under the microscope. Sporopollen results mainly include the percentage content and number of trees, shrubs, herbs, aquatic, ferns and other families and genera.
HU Xiaofei, PAN Baotian
Since the formation of heihe, palynology data samples were collected from the borehole formation of dasunken well in the middle reaches of heihe.Borehole location: 39.491 n, 99.605 e.The borehole has a depth of 140 meters and 18 palynological samples are collected from top to bottom. Currently, there are 3 palynological results, which are distributed in each sedimentary phase from top to bottom.Impurities such as carbonate, organic matter and silicate were removed from palynology samples in the laboratory, and the palynology types and data were identified under the microscope.Palynology results mainly included the percentage and number of trees, shrubs, herbs, aquatic and ferns.
PAN Baotian, HU Xiaofei
Airborne pollen is mainly produced and disseminated during the process of plant flowering, controlled by plant phenology and climatic conditions. As an important bioindicator of plant behavior, airborne pollen can supply information about reproductive phenology, climate and atmospheric circulations. From 2011 to 2013, airborne pollen samples were collected using a volumetric Burkard pollen trap at the Qomolangma Station for Atmospheric and Environmental Observation and Research, Chinese Academy of Sciences (QOMS, 28.21°N, 86.56°E; 4276 m a.s.l.), on the northern slope of the Himalayas. The sampler is a volumetric air-suction device capable of continuously gathering pollen and spore particles. Air is drawn in at a speed of 10 l/min, and airborne particles are deposited on a sticky tape mounted on a drum that makes one complete rotation per week. The tape is changed weekly after a complete rotation. Then, the tape is removed and cut into seven pieces, with each piece representing one day of sampling. The pieces are mounted on slides using glycerin and safranin. Identification and counting of pollen grains were performed under an Olympus BX41 microscope at 400× magnification; all pollen grains on each slide were counted . Pollen concentration was expressed as the daily pollen grains per cubic meter of air using a constant air intake speed of 10 l/min. The pollen concentration and percentage of each pollen taxon in each year were calculated. The pollen sampling and lab process were followed the standard methods to ensure the authenticity and reliability of the data. The pollen data can provides insights into vegetation response to climate change and has significance for interpreting fossil pollen records.
LÜ Xinmiao
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