Using sedimentary diatoms to identify reference conditions and historical variability in shallow lake ecosystems in the Yangtze floodplain
Using sedimentary diatoms to identify reference conditions and historical variability in shallow lake ecosystems in the Yangtze floodplain
复制标题
利用沉积硅藻确定长江漫滩浅湖生态系统的参考条件和历史变化
DOI：
10.1071/mf14262
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发表时间：
2016-01-01
影响因子：
1.8
通讯作者：
Xu, Min
中科院分区：
文献类型：
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作者：
Dong, Xuhui;Yang, Xiangdong;Xu, Min
湿地生态系统的参考条件和历史变异性是理解湿地系统动态和生态评价的关键生态特征。根据长江漫滩10个湖泊硅藻记录的高分辨率年代序列，研究了它们的生态和化学参照条件、历史变异及其控制因素。中营养种Aulacoseria granulata，沿着与非中营养种Fragilaria spp.，舟形藻属，胎盘卵形藻、微小曲壳藻、桥弯藻。等在参比样品（1800-50）中含量最高。因此，确定了相对较高的化学参考值（以生物测定法推断的总磷浓度为50 µg L-1）。植物区系的变化程度与参考样本比较显示，10个湖泊中有6个发生了显着的生态变化。这些湖泊的历史变异性被发现，从长江（负）和湖泊集水区（正）的距离调节。这反映了洪泛区湖泊生态变化的驱动机制：生态条件对来自流域的营养盐输入和长江的干扰非常敏感。本研究表明，古湖泊学技术在重建湖泊生态系统的历史生态特征，这可能会提供必要的信息，更广泛的类型的湿地管理的鲁棒性。
The reference condition and historical variability of aquatic ecosystems are key ecological characters for understanding the dynamic and ecological assessment of wetland systems. Based on high-resolution chronological sequences of diatom records from 10 lakes in the Yangtze floodplain, this study aims to determine their ecological and chemical reference conditions, the historical variability and its controlling factors. Mesotrophic species Aulacoseria granulata, along with non-planktonic species Fragilaria spp., Navicula spp., Cocconeis placentula, Achnanthidium minutissimum, Cymbella spp. etc, were most abundant in the reference samples (1800–50). Accordingly, a relatively high chemical reference (50 µg L–1 in diatom-inferred total phosphorus concentration) was defined. The degree of floristic change comparing present with reference samples reveals that six of the 10 lakes have undergone significant ecological changes. The historical variability in those lakes was found to be regulated by the distance from the Yangtze River (negatively) and the lake catchment area (positively). This reflects the mechanism driving ecological change in floodplain lakes: the ecological conditions were sensitive to the nutrient input from the catchment and disturbance by the Yangtze River. This study demonstrates the robustness of palaeolimnological techniques in reconstructing the historical ecological characters of lake ecosystems, which may provide essential information for the management of wider types of wetland.