水生态学杂志2016，Vol.37Issue(2)：24-33,10.DOI:10.15928/j.1674-3075.2016.02.004
三峡库区万州段消落带植被及土壤理化特征分析
Characteristics of Vegetation and Soil in the Water Level Fluctuation Zone of the Wanzhou Region of Three Gorges Reservoir
摘要
Abstract
Hydrological regime is a main driver of plant community succession in riparian zones.Soil that has been influenced by hydrology also affects the overlying vegetation.The goal of this study was to determine the effects of periodic submergence on the habitat and vegetation in the fluctuation zone of Three Gorges Reservoir after the five years of water-level fluctuation,since impoundment first reached 175m in 2010.The characteristics of vegetation and physical-chemical properties of soil in the water level fluctuation zone of the Wanzhou region of Three Gorges Reservoir were investigated from August 17 to September 2,2015.Eight sampling sites were selected on the main stem of the Yangtze River and its tributaries.A total of 96 plots were set within twenty-four sampling belts (10 m × 30 m)established at three elevations:145 -155 m,156-165 m and 166-175 m.The height,cover and biomass of each plant in the sampling plots were determined and soil samples were collected at each sampling belt for analy-sis of pH,soil organic matter (SOM),total nitrogen (TN),available nitrogen (AN),total phosphorus (TP)and available phosphorus (AP).A total of 5 1 vascular plants species,belonging to 47 genera and 22 families,were re-corded in the water level fluctuation zone of the Wanzhou section,with abundant species of Gramineae,Asterace-ae,Polygonaceae and Cyperaceae.Vegetation was dominated by herbaceous plants,and the annual herbs and pe-rennial herbs accounted for 58.8%and 27.5%of the plant community.The dominant plant species varied with el-evation.Plant species with high importance values included Cynodon dactylon,Echinochloa crusgallivar.mitis and Eclipta prostrate at 145 -165 m and Bidens pilosa,Setaria viridis and Cynodon dactylon at 166-175 m.The fresh weight of plants was highest in the 156-165 m elevation belt at (2 199.1 ±863.9)g/m2.The Shannon-Wiener diversity index and the Pielou evenness index were highest in the 166 -175 m elevation belt,averaging (2.00 ± 0.30)and (0.85 ±0.06).Fresh weight and total coverage of vegetation declined with increasing slope.The spe-cies number was richest in the slope range 6°-15°.The average fresh weight,height,Shannon-Wiener diversity index and Pielou evenness index of the plant community on the left bank were higher than those on the right bank. The soil physical-chemical characteristics exhibited obvious spatial heterogeneity.The mean value and standard de-viation of soil density,pH,SOM,TN,AN,TP and AP were,respectively,(1.34 ±0.09)g/cm3,(7.60 ± 0.47),(6.02 ±294)g/kg,(1.21 ±0.16)g/kg,(53.42 ±9.67)mg/kg,(0.42 ±0.14)g/kg,(6.55 ± 2.82)mg/kg.The variation coefficient of SOM was the highest,followed by AP and TP.The average pH,SOM, TN and AN on the southeast-facing bank were lower than those on the northwest-facing bank.The importance value of species was also found to be significantly affected by submergence time and available phosphorus.关键词
三峡水库/消落带/植物群落/重要值/土壤性质Key words
Three Gorges Reservoir/water level fluctuation zone/plant community/importance value/soil prop-erties分类
农业科技引用本文复制引用
张志永,程郁春,程丽,万成炎,李金波..三峡库区万州段消落带植被及土壤理化特征分析[J].水生态学杂志,2016,37(2):24-33,10.基金项目
国家水体污染控制与治理重大专项（2013ZX07104-004）；三峡后续工作科研项目（2013HXKY2-3）。 （）
