三峡水库消落带植被分布规律及对磷迁移和鱼产力的影响  

DISTRIBUTION OF VEGETATION IN THE WATER-LEVEL-FLUCTUATION ZONE OF THE THREE GORGES RESERVOIR AND ITS EFFECTS ON PHOSPHORUS TRANSFER AND FISHERY PRODUCTION

作　　者：汪志聪[1] 周维成[1,2] 李晓宇 彭成荣 李敦海[1] WANG Zhi-Cong;ZHOU Wei-Cheng;LI Xiao-Yu;PENG Cheng-Rong;LI Dun-Hai(Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院水生生物研究所,武汉430072 [2]中国科学院大学,北京100049

出　　处：《水生生物学报》2023年第3期436-449,共14页Acta Hydrobiologica Sinica

基　　金：国家重点研发计划“蓝色粮仓科技创新”专项(2019YFD0900603)资助。

摘　　要：为了探究三峡水库消落带植被的分布规律及其对库区生态环境和渔业的潜在贡献,对秭归、云阳和忠县库区共计30个典型消落带断面的植物群落结构特征、植物营养成分、断面坡度及土壤理化特性进行了调查分析。结果表明,(1)共发现54科、61属、209种植物,其中狗牙根(Cynodon dactylon)和苍耳(Xanthium sibiricum)为主要优势种,平均盖度分别为29.73%和26.87%;随着水位高程逐渐降低,狗牙根、喜旱莲子草(Alternanthera philoxeroides)和茼麻(Abutilon theophrasti)的盖度逐渐增加,苍耳、草木犀(Melilotus officinalis)和狼粑草(Bidens tripartite)的盖度逐渐降低,而葎草(Humulus scandens)、狗尾草(Setaria viridis)和酸模叶蓼(Polygonum lapathifolium)的盖度先增加后降低;植被的分布还受到断面坡度的影响,狗牙根的盖度与坡度呈显著负相关(P<0.001),而苍耳的盖度则随着坡度呈现先增后降的显著单峰形态分布(P<0.001)。较高的土壤含水率促进了以狗牙根为主的共优势群落的形成,而随着土壤含水率降低,植被类型逐渐演替成以苍耳为主的共优势群落;(2)低水位高程(150—160 m)消落带地表土壤呈现明显的磷吸收趋势,而高水位(160—175 m)表层土壤则呈现明显的磷释放趋势,这与样地的植被类型和土壤微生物群落结构特征密切相关;(3)三峡水库消落带狗牙根和苍耳的地面鲜重总量为2.51×10^(8)和2.48×10^(8)kg,它们的鲜重总量和蛋白质含量均远高于其他植物,对库区渔产潜力贡献分别为1.25×10^(8)和1.24×10^(8)kg。综上,三峡库区消落带植被的主要优势种为狗牙根和苍耳,植被的分布主要受到水位高程、断面坡度和土壤含水率的影响。消落带植被在库区陆源磷营养截留、水体磷营养调控和鱼产力贡献方面具有较高的生态服务功能价值。研究可为评估水库消落带的生态渔业功能及研发水库消落带的植被修复技术提供重要参考。The water-level-fluctuation zone(WLFZ)of the Three Gorges Reservoir(TGR)has the characteristics of large water level drop,wide area and high vegetation coverage.In order to explore the distribution law of vegetation in the WLFZ of the TGR and its potential contribution to the ecological environment and fishery in the reservoir area,the plant community structural characteristics,plant nutritional components,section slope and soil physical and chemical characteristics of 30 typical sections of the WLFZ in Zigui,Yunyang and Zhongxian Reservoir areas were investigated and analyzed.The results showed that:(1)209 species belonging to 61 genera and 54 families were found,of which Cynodon dactylon and Xanthium sibiricum were the main dominant species,with an average coverage of 29.73%and 26.87%,respectively.With the decrease of water level elevation,the coverage of C.dactylon,Alternanthera philoxeroides and Abutilon theophrasti gradually increased,the coverage of X.sibiricum,Melilotus officinalis and Bidens tripartite gradually decreased,while the coverage of Humulus scandens,Setaria viridis and Polygonum lapathifolium first increased and then decreased.The distribution of vegetation was also affected by the slope of the sampling sections.The coverage of C.dactylon was significantly negatively correlated with the slope(P<0.001),while that of X.sibiricum showed a significant single peak distribution(P<0.001).Higher soil moisture content promoted the formation of common dominant communities dominated by C.dactylon,and with the decrease of soil moisture content,vegetation types gradually succeed to common dominant communities dominated by X.sibiricum;(2)The surface soil in the WLFZ at low water level elevation(150—160 m)showed an obvious phosphorus absorption trend,while the soil at high water level elevation(160—175 m)showed an obvious phosphorus release trend,which was closely related to the vegetation types and the soil microbial community structure characteristics of the sampling plots;(3)The total ground fresh weig

关 键 词：消落带 植被分布 鱼产力 三峡水库 

分 类 号：Q178.2[生物学—水生生物学]