Earth Science Frontiers ›› 2020, Vol. 27 ›› Issue (6): 289-299.DOI: 10.13745/j.esf.sf.2020.6.22

Previous Articles     Next Articles

Rapid response of diatom biodiversity to millennial-scale abrupt change of climate: a case study of the last glacial record of the Yunlong Lake, Yunnan Province

LUO Hai1(), LI Jie1,*(), ZOU Yafei2, XU Huiming3   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2. Yunnan Key Laboratory of Earth System Science, Yunnan University, Kunming 650500, China
    3. Management and Protection Bureau for Yunlong Tianchi National Nature Reserve, Yunlong 672700, China
  • Received:2020-03-19 Revised:2020-05-28 Online:2020-11-02 Published:2020-11-02
  • Contact: LI Jie

Abstract:

Lakes are an important component of the global ecosystems. Although biodiversity plays a very important role in lake’s primary productivity and lake ecosystems, little is known about how it responded to climate change on the millennial timescale most relevant for predicting future changes. Diatoms are one of the important primary producers in lakes and their siliceous valves can be stably preserved in lake sediments for a long time, so they are an excellent indicator for the study of lake biodiversity changes in geologic times. In this study, we use diatom records from a 10.63 m comprehensive core obtained in the Yunlong Lake, southwest monsoon region of China to reveal the response of the lake biodiversity to the rapid climate change on the millennium timescale. The final age of the core was determined by Accelerator Mass Spectrometry (AMS)14C dating and Bacon age-depth modelling. Combining with diatom assemblage and α-diversity analysis, the evolutionary history of diatom diversity in the last deglaciation (569-1 063 cm, 19~10 calkyr B.P.) of the lake was constructed. The diatom assemblage and diatom diversity changes in the Yunlong Lake during the last glaciation can be divided into six intervals, including the late Last Glacial Maximum (LGM), the Early Last Deglaciation (E-LD), Herinrich 1 (H1), Bolling/Allerod (B/A), Younger Dryas (YD), and the Early Holocene (E-Holo). The variation of diatom diversity was generally high during warm periods (E-LD, B/A) and low during cold periods (LGM, H1, YD). At the same time, with the rapid change of global temperature, diatom diversity also responded rapidly: it increased rapidly when temperature turned warm (B/A warm period) and decreased rapidly when temperature turned cold (H1 and YD). These changes were mainly related to the changes of lake environmental conditions (such as the length of ice-cover period and the changes of aquatic vegetation in littoral zone, etc.) driven by temperature changes. Our results show that during the last deglaciation period, diatom biodiversity responded quickly to the millennium-scale abrupt climate events and synchronized with rapid climate fluctuations; on a long timescale, climate warming may be beneficial to the maintenance of biodiversity of alpine lakes.

Key words: diatom, biodiversity, last deglaciation, millennial-scale, Yunlong Lake

CLC Number: