Relationships between surface pollen and vegetation in the Meiling Mountains, southeast China : an aid to reconstruct past vegetation dynamics

Fang, Yiman

Abstract

Understanding the relationships between modern pollen deposits and their surrounding vegetation is an important tool to improve the quality of reconstructions and interpretations of past vegetation changes from fossil pollen records. The overall aim of this research project is to validate and calibrate mathematical models of relationships for assemblages deposited in peatland and forest landscapes in southeast China, which will form an essential basis for quantitative reconstruction of past land cover from Quaternary peat deposits in the region. This field study area presents great challenges, being spatially large in extent compared to studies in northwestern Europe and of difficult and inaccessible mountainous terrain, which makes the vegetation survey (10m-100m) time-consuming.

Firstly, a study to decide whether to use moss or soil surface samples is presented. 42 paired moss and soils sample were collected in the five main forest types. Similar levels of variation in the pollen spectra are seen, but there are systematic differences in the mean values of key groups of taxa. Moss polsters are chosen since they record the most accurate representation of the contemporary vegetation.

Secondly, the behaviour of several pollen dispersal and deposition models is tested against a grassland-forest transect. The Prentice-Sugita model passed the test and is therefore considered suitable for use.

Thirdly, the first estimates of relative pollen productivity (RPP) for 9 key taxa (Castanea, Cryptomeria, Cyclobalanopsis, Liquidambar, Pinus, Poaceae, Quercus, Rosaceae and Theaceae) are presented. Two alternative methods (modified Davis method and iteration method) for estimating RPP are also developed, which have great potential for use in wider areas.

Fourthly, wetland herb taxa are important in the pollen spectra from mire records, therefore surface samples were taken from a mire surface. They show that there are inter-annual differences in pollen from wetland herbs.

Finally, the discussion presents suggestions for how these findings can be best applied to land-cover reconstruction, explores the strengths and limitations of the study and identifies future directions which such work could take.

Citation

Fang, Y. (2018). Relationships between surface pollen and vegetation in the Meiling Mountains, southeast China : an aid to reconstruct past vegetation dynamics. (Thesis). University of Hull. Retrieved from https://hull-repository.worktribe.com/output/4221270

• Thesis Type: Thesis
• Deposit Date: Feb 13, 2019
• Publicly Available Date: Feb 23, 2023
• Keywords: Geography
• Public URL: https://hull-repository.worktribe.com/output/4221270
• Additional Information: School of Environmental Sciences, The University of Hull
• Award Date: Oct 1, 2018