摘要
针对近二十多年来珠江口咸潮异常上溯可能引起的水生态环境变化,首次通过对磨刀门水道上、中、下游各河段及出海口现场踏勘和植物样方调查并参考有关文献资料,系统研究了咸潮上溯对珠江口主要入海河道水生植物群落分布的影响,结果表明:(1)磨刀门水道及出海口沿岸植被分布具有明显的差异:下游河段和出海口门处耐盐的红树、半红树植物明显占优,种类也多;中游河段咸、淡水植物均为优势种;而上游河段虽然优势种仍为淡水植物,但也出现了原本在下游和口门处常见的咸水植物。(2)河道水体盐度的变化已反映在植被分布变化上,主要表现为与正常情况下的河口植物种群分布相比,在河道中应完全是淡水植物分布的河段变为淡水植物、广适性植物和半咸水植物共同分布。(3)咸潮超常上溯是导致入海河道上、中游河段植物优势群落由喜淡水植物群落演替为广适性植物群落和半咸水(咸水)植物群落的根本原因。
For the variation of aquatic ecological environment probably caused by unusual saltwater intrusion in Pearl River Estuary （PRE） over the past two decades, on-site monitoring and quadrat surveying, as well as referencing related literatures were conducted for the first time to systematically investigate the influence of the distribution of aquatic plant community by salt water intrusion in the main seagoing channels in PRE. Results showed there were significant differences among the distributions of coastal vegetation in Modaomen water courses and marine outfall, with haloduric mangrove and semimangrove distinctively dominated in downstream watercourse and estuary, while saltwater and freshwater plant both dominant in midstream watercourse. However the saltwater plant originally often found in the downstream watercourse and estuary was also present in the upstream watercourse where the freshwater plant was dominant. Salinity variation of the water course was already reflected in the variation of the vegetation distribution, which showed that in watercourse freshwater, eurytopic and semi-salt water plant co-existed instead of only freshwater plant presumably existing compared with distribution of estuarine plant population under normal circumstances. Unusual saltwater intrusion was the primary reason for the succession of plant community structure from fresh water plant community to eurytopic and semi-saltwater （salt water） plant community in upstream and midstream watercourse of seagoing channels.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2014年第8期21-25,共5页
Environmental Science & Technology
基金
环保公益性行业科研专项(200709049)
关键词
珠江口
咸潮上溯
水生植物
群落
Pear River Estuary
saltwater intrusion
aquatic plant
community
