Surface pollen distribution in alpine zone of the higher Himalaya: a case study from the Kalla glacier valley, India

ABSTRACT

In order to understand the relationship between modern pollen spectra and vegetation, we analysed 20 surface sediment samples collected from the alpine zone of Kalla Bank glacier valley, Dhauliganga Basin, India covering an elevational stretch of c. 3600 to 5000 m asl and vegetation zones like the alpine scrub, alpine meadow and alpine barren. This study also provides insights into the vertical pollen transport along the elevational gradient of the glacier valley. Numerical analyses such as cluster analysis (CA), discriminant analysis (DA) and detrended correspondence analysis (DCA) are used to explore and discuss the modern pollen deposition patterns in the alpine settings. Despite the inconsistencies observed between modern vegetation and surface palynoassemblages, a good agreement is noticed between CA and DA classifications and DCA ordination results which reveal signature of upslope wind transport. High percentages of pine, cedar, alder and birch pollen grains in the above tree-line surface pollen assemblages are indicative of their upslope wind transport from a lower elevation. The inconsistencies may be attributed to the differential pollen representation between species, differential flowering and pollination of herbaceous taxa. The present study suggests altitude and monsoonal winds might be the two most influential factors that attributed changes in the surface palynoassemblages of the alpine vegetation in the Kalla Bank glacier (Kunti-Banar) valley. Therefore, while interpreting the fossil pollen spectra from any high altitude mountainous zone, long-distance pollen transport should always be taken into account, especially for anemophilous plant taxa.

KEYWORDS:

• Pollen spectra
• classification and ordination analyses
• alpine vegetation
• glacier valley
• Himalaya

Author contributions

Idea was conceived by SNA, MFQ and PB. Work was carried out by SNA, PB and PP. The pollen analysis was done by SNA, MFQ, JD and RG while the statistical analysis was done by PM and MS. The MS was written mainly by SNA, JD and RG, with inputs from all the team.

Acknowledgments

The authors are thankful to the Director, Birbal Sahni Institute of Palaeosciences, Lucknow, India for providing laboratory facilities. This work was carried out with financial support from the Department of Science and Technology (DST), Government of India, India (Ref. No. SR/FTP/ES-23/2013). Further thanks are extended to the editor and two anonymous reviewers for their constructive feedback and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Science and Engineering Research Board [SR/FTP/ES-23/2013].