博文
摘要6 繁殖体库在周期性枯水湖岸沼泽湿地植被周期性变化中的作用
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繁殖体库在周期性枯水湖岸沼泽湿地植被周期性变化中的作用
中国长江中游的梁子湖周边湖泊湿地年水位变化1.5m。低水位时，植被主要由沼生植物和挺水植物组成；而在雨季，当关闸时（6至9月），湿地则被淹没且植被优势物种迅速变为沉水、浮叶和高大挺水植物物种。将沼泽种子库和植被繁殖体库与枯水期和丰水期的植被类型的物种组成和丰度进行比较。这些数据提供了一个测试来验证van der Valk北温带季节性植被变化模型在亚热带有着周期性植被变化的淡水湿地的预测能力。繁殖体库中有着丰富的物种。我们发现种子库决定了两个时期的植被类型，而植被繁殖体库组成了枯水期植被的优势种。水深条件、种子和无性繁殖体一起决定了枯水和丰水期生长植被的结构。van der Valk的演替模型很好的预测了植被周期性变化。卡方检验表明不论枯水期还是丰水期，预测和实际植被没有显著性差异。
How does the propagule bank contribute to cyclic vegetationchange in a lakeshore marsh with seasonal drawdown?
Gui-hua Liu a,*, Wei Li a, Jin Zhou b, Wen-zhi Liu a, Dong Yang a,Anthony J. Davy c
a Laboratory of Aquatic Plant Biology, Wuhan Botanical Garden, The Chinese Academy of Sciences,Wuhan 430074, China
b Department of Phytology, Laval University, Que., QC, Canada G1K 7P4
c Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia,Norwich NR4 7TJ, UK
Received 20 September 2004; received in revised form 12 July 2005; accepted 10 August 2005
Abstract
Lakeshore marshes around Liangzi Lake, in the middle reach of the Yangtze River, China, experience annual changes of water level of c. 1.5 m. During the drawdown period, the vegetation is structured by helophytes and emergents; during the rainy season when the dams are closed (June– September) the marshes are flooded and their vegetation rapidly changes to be come dominated by submerged, floating-leaved and tall emergent species. The species composition and abundance of both the marsh seed bank and the vegetative propagule bank were compared with those of the drawdown and flooded vegetation types. These data provided a test of the predictive power of van der Valk’s model of northern temperate seasonal vegetation change in a subtropical, freshwater wetland with cyclic vegetational change. The abundant species were detected in the propagule bank. The seed bank was found to determine the species richness of both types of the vegetation, whereas the vegetative propagule bank consisted of the dominants of the drawdown vegetation. Water depth conditions, and the composition of seed and vegetative propagules banks together determine the structure of the standing vegetation during drawdown and flooding. van der Valk’s succession model was found to predict the seasonal vegetation change reasonably well. The Chi-square test showed no significant difference between predicted vegetation and actual vegetation in both drawdown and flooding periods.
Keywords: Flooding; Freshwater wetland; Seasonal drawdown; Seed bank; Succession; Vegetative propagule
https://blog.sciencenet.cn/blog-272085-400186.html
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