Prof. CAO Xianyong(corresponding author and first author)'s team recently published an article entitled "Lake surface sediment pollen dataset for the alpine meadow vegetation type from the eastern Tibetan Plateau and its potential in past climate" in Earth System Science Data (IF=11.33) in collaboration with researchers from Capital Normal University and Zhejiang Normal University. It introduces a modern pollen dataset with an even distribution of sites is essential for pollen-based past vegetation and climate estimations. As there were geographical gaps in previous datasets covering the central and eastern Tibetan Plateau, lake surface sediment samples (n=117) were collected from the alpine meadow region on the Tibetan Plateau between elevations of 3720 and 5170 m above sea level. The corresponding dataset is published at the National Tibetan Plateau/Third Pole Environment Data Center (https://data.tpdc.ac.cn), and is openly available to users.

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.

In order to systematically carry out research on modern processes of pollen on the Qinghai Tibet Plateau, since 2018, relying on the Strategic Priority Research Program of Chinese Academy of Sciences and the Second Tibetan Plateau Scientific Expedition Program, Prof. CAO Xianyong, together with researchers from several units, has collected 401 plant specimens (covering 55 families) and constructed an atlas of common plant pollen patterns on the eastern Tibetan Plateau (published at the National Tibetan Plateau/Third Pole Environment Data Center); collected surface sediment samples from 117 lakes in the alpine meadow area (this dataset); and also collected soil samples for modern pollen yield estimation in the alpine meadow and alpine grassland areas. Soil samples and gridded uniformly distributed surface soil samples (more than 750) were collected. The research team is currently conducting research and analysis of the above data and samples, and more data and research results will be available in the near future to improve our understanding of the quantitative relationships between modern pollen and vegetation (including community characteristics such as cover and abundance) and climate on the Tibetan Plateau.

With this current modern pollen dataset extracted from lake surface sediments, it was found that 1) the modern pollen of alpine meadows is dominated by pollen types of Cyperaceae, Poaceae, Ranunculaceae, Artemisia, and Asteraceae, which can well represent the plant community composition of alpine meadows; 2) redundancy analysis and boosted regression tree analysis and other analyses found that precipitation is the main controlling factor affecting the spatial distribution of pollen in the region; Gramineae pollen indicates drought, while Salicaceae pollen represents wet environment; 3) the random forest algorithm has potential for development in pollen reconstruction of paleoclimate. The construction and public release of this dataset will promote the development of quantitative reconstructed palevegetation and paleoclimate studies of pollen on theTibetan Plateau.

Realizing open sharing of scientific data and enhancing the efficiency of data resource utilization is an inevitable trend of scientific development. The pollen data are important basic data for conducting paleogeography, palevegetation and paleoclimate research, and are also important constraints for vegetation and climate models. The pollen data sharing is conducive to expanding the influence of pollinology on related research fields and promoting the development of research in pollinology and related fields.

Article:

Cao, X.Y., Tian, F., Li, K., Ni, J., Yu, X.S., Liu, L.N., & Wang, N.N., 2021. Lake surface sediment pollen dataset for the alpine meadow vegetation type from the eastern Tibetan Plateau and its potential in past climate reconstructions. Earth System Science Data, 13(7): 3525-3537.

Article available at:

https://doi.org/10.5194/essd-13-3525-2021

Data:

Cao, X., Tian, F., Li, K., Ni, J. (2021). Lake sediment-surface pollen dataset for alpine meadow in eastern Tibetan Plateau. National Tibetan Plateau Data Center, DOI: 10.11888/Paleoenv.tpdc.271191. CSTR: 18406.11.Paleoenv.tpdc.271191.

Data available at:

https://data.tpdc.ac.cn/en/data/d2dc3785-e3e6-4d35-bd9f-bfb039f5ba53/