Holocene vegetation-hydrology-climate interactions of wetlands on the Heixiazi Island, China

Zhenqing Zhang; Thomas A Bianchette; Caihong Meng; Qinghai Xu; Ming Jiang

doi:10.1016/j.scitotenv.2020.140777

Holocene vegetation-hydrology-climate interactions of wetlands on the Heixiazi Island, China

Sci Total Environ. 2020 Nov 15:743:140777. doi: 10.1016/j.scitotenv.2020.140777. Epub 2020 Jul 7.

Authors

Zhenqing Zhang¹, Thomas A Bianchette², Caihong Meng³, Qinghai Xu⁴, Ming Jiang⁵

Affiliations

¹ School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China. Electronic address: zhangzq@iga.ac.cn.
² Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI 48128, USA.
³ Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
⁴ College of Resources and Environment Science, Hebei Normal University, Shijiazhuang 050024, China.
⁵ Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; Jillin Provincial Joint Laboratory of Changbai Mountain Wetland and Ecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.

PMID: 32673922
DOI: 10.1016/j.scitotenv.2020.140777

Abstract

An integrated view of wetland's evolution is currently poorly understood due to a lack of knowledge on long-term interactions of multiple ecological factors. Here, we present a cored palynological record covering the Holocene Epoch from a depressional wetland on Heixiazi Island (China). With the aid of principal component analysis and cluster analysis of the palynological data, the historical vegetation regime has been well reconstructed for wetlands on the island. With further assistance from the published data on local hydrology and regional East Asian summer monsoon (EASM) variations, the interactions of vegetation, hydrology, and climate in the island's wetlands have been thoroughly analyzed with correlation analysis of the three factors. The results indicate that a strong EASM generally led to a high water level in the wetlands from increased monsoonal precipitation, causing an increase in arboreal vegetation and a decrease in herbs. Alternatively, a weak EASM generally led to low water levels due to decreased monsoonal precipitation, causing a decrease in arboreal vegetation and an increase in herbs. The local vegetation regime during the early Holocene was marked by an increase in tree/herb ratio due to rising water levels under the influence of an increasingly strengthened EASM. Subsequently, a general decline of the tree/herb ratio occurred from a gradual decrease in water level during the mid and late Holocene when the EASM gradually retreated. The wettest stage marked by the highest water level and tree/herb ratio occurred 8.0-4.6 ka BP with the strongest EASM. The driest stage occurred during the last 0.4 ka BP, which was attributed to both the weakest EASM influence and anthropogenic disturbance. Our study provides an integrated view of the wetlands' ecological dynamics incorporating multi-factor interactions, which further sheds light on the EASM driving mechanisms on wetlands evolution during the Holocene Epoch.

Keywords: Heixiazi Island; Holocene; Monsoon; Pollen; Wetland.