J Integr Plant Biol. ›› 1983, Vol. 25 ›› Issue (3): -.

• Research Articles •    

Palynoflora of the Qarhan Saline Lake and Its Significance in Geography and Botany The S poro-Poilen Assemblages from CK2022 Drilling Core at the Bieletan

Du Nai-qiu and, Kong Zhao-chen   

Abstract: The pollen analytical investigations of a 101 m deep CK2022 drilling core from Bieletan of the Qarhan saline lake have been carried out. The Qarhan saline lake is situated at the Qaidam Basin. The climate is cold and dry. Annual mean temperature is about 0.1 ℃, and annual precipitation is 28–40 mm. The vegetation is of desert type, mainly composed of Chenopodiaceae, Compositae, Tamaricaceac, Cruciferae, Zygophyllaceae, Leguminosae and Gramineae. Gymnospermae are very poorly represented e. g. Ephedra and Sabina. Ferns are even scanty. Based on the characteristics of CK2022 drilling core sporopollen assemblages 32,000 4,000 years ago five zones may be subdivided in ascending order as follows: 1. In the first zone, the vegetation during the past 31, 000–25, 600 years was represented by a temperate shrub and semi-shrub desert plants, such as Chenopodiaceae, Artemisia and Nitraria were predominant. The hydrophytes, such as Typha and Pediastrum boryanum, apparently increased. The climate was wet and rather warm. By this time, lakes and bogs were better developed in this area. 2. In the second zone (Ⅱ), green algae was very flourishing, which indicates a shallow, stagnant and more or less mesotrophic fresh water habitat. The climate was wet and cold, The lakes and bogs were better developed. 3 . In the third zone (Ⅲ), the vegetation consisted of Ephedra, Chenopodiaceae, Artemisia and Nitraria. At the same time subalpine conifer and Betula may have grown by rivers. The climate was warmer and drier than before. 4. In the fourth zone (Ⅳ), Shrubby and semi-shrubby deserts were better developed, but trees, ferns and algae were obviously reduced 18, 000–11, 000 years ago. The climate was very dry and cold. 5. In the fifth zone (Ⅴ), Ephedra, Chenopodiaceae, Artemisia and Nitratia were still flourishing. Hydrophytes, some trees and mesophytes plants and Polypodiaceae appeared again. Due to the increased temperature at this zone, the Pleistocene Holocene boundary should be demarcated at about 11000 years. BP Since 30000 years age there were alternation of dilution and salinization once and again.

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