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Different morphology of Nuphar lutea in two contrasting aquatic environments and its effect on ecosystem engineering 
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下载免费PDF全文 Jonas Schoelynck Kris Bal Veerle Verschoren Ellis Penning Eric Struyf Tjeerd Bouma Dieter Meire Patrick Meire Stijn Temmerman 《地球表面变化过程与地形》2014,39(15):2100-2108
Aquatic plants (macrophytes) can have a large effect on river hydraulics and geomorphology. Though, the extent to how plant morphological plasticity actively influences these feedbacks has received little scientific attention. The nymphaeid macrophyte species Nuphar lutea (L.) Smith is characterized by a distinct leaf duality. Floating leaves shade most of the submerged leaves thereby limiting light penetration in the water. Despite their apparent negligible photosynthetic role, submerged leaves of N. lutea remain intact during summer and contribute a significant part to the total biomass. Our results indicate that the submerged leaves are crucial in plant–flow interactions and hence in the engineering potential of the plant, i.e. the capacity to locally reduce flow velocities and to promote sedimentation, including organic matter deposition. Plant individuals growing in running river water were compared to individuals from adjacent oxbow lake water. The number and size of submerged leaves were significantly higher for river standing individuals and the accumulated sediment contained significantly more organic matter, total nitrogen and total phosphorus, and was characterized by a lower carbon/nitrogen ratio and a finer grain size. We therefore argue that the submerged N. lutea canopy in rivers has the ability to create a high‐nutrient, low hydrodynamic environment, resembling the conditions found in oxbow lakes. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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于2018年68月在长江下游菜子湖流域沿岸带、敞水区、湖口和河道4种典型微生境分别设置样点进行鱼类调查,探讨生境过滤对鱼类物种和功能组成的影响.共采集鱼类5目31属43种,其中沿岸带湖泊定居性、山溪河流性及江湖洄游性鱼类物种数均较低,河道山溪河流性鱼类物种数较高.通过对各微生境间物种组成的差异分析,显示出4种微生境条件下的鱼类群落均有显著差异,且沿岸带、敞水区和河道的代表种分别为、鳙、草鱼、鲢,华鳈、光唇蛇鮈、蛇鮈.通过单因素多元方差分析解析不同生境过滤条件下鱼类物种和功能多样性的差异,发现在物种多样性层面,沿岸带的Richness指数和Shannon-Wiener指数显著低于其他微生境;在功能多样性层面,不仅发现沿岸带显著较低的RaoQ指数,同时发现河道的FDiv指数显著高于其他微生境类型. 相似文献
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梅梁湾是太湖北部最大湖湾,也是太湖生态环境问题最严重的区域之一,近年来对太湖治理力度不断加大,然而对其生态状况演变的认识尚不清晰。本文基于长期监测及文献资料,获得1980s以来太湖梅梁湾底栖动物及环境因子数据,分析底栖动物种类组成、优势种、丰度的时空变化,应用非度量多维尺度分析(NMDS)和随机森林(RF)分析群落结构演变及其与环境因子的关系。结果表明,梅梁湾1980—2019年共记录到44属(种)底栖动物,以摇蚊幼虫和软体动物为主,总丰度年际变化显著,40年来底栖群落结构发生显著变化,优势种经历了由较敏感的软体类为主到以耐污寡毛类、摇蚊幼虫等为主的转变。综合NMDS和随机森林分析结果,梅梁湾底栖动物群落演变大致可分为4个阶段:1980s及以前,物种多样性丰富,以河蚬(Corbicula fluminea)等大型软体动物为优势种;1990s—2007年,底栖动物群落快速退化,以耐污种占优;2008—2016年,水生态略有恢复,河蚬等清洁种略有回升;2017—2019年,耐污种优势度和丰度反弹。近40年来梅梁湾底栖动物群落变化主要受底质氮磷、有机质和水体营养盐、蓝藻水华等环境因子变化的影... 相似文献
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从1950s开始, 云南地区部分湖泊受到了水文调控(如筑坝)和鱼类引入等流域开发活动的直接影响, 湖泊水环境与生态系统结构已出现明显改变. 开展浮游动物群落的长期生态响应评价有助于认识气候波动和人为胁迫的影响模式. 本文选取云龙天池进行了沉积物记录分析, 在重建过去100年环境变化历史的基础上开展了枝角类群落的多指标分析(物种组成、个体大小、生物量等), 进一步结合多变量分析识别了枝角类群落构建的关键驱动因子. 结果显示, 云龙天池在过去100年间经历了明显的水位波动, 约1962年以前水位较低, 1950s起的水文调控(筑坝)导致湖泊水位波动上升, 2006年以来略有下降. 枝角类群落随水位波动呈现由底栖种向浮游种占优转变的模式, 并在2006年以来底栖种略有增加. 总体上, 低水位时期底栖枝角类占优, 高水位时期浮游枝角类占优. 水体营养水平也对枝角类群落产生了较为显著的影响. 在沉积物总氮和有机质通量上升时, 长额象鼻溞(Bosmina longirostris)相对丰度和枝角类浓度都明显上升. 枝角类象鼻溞个体大小表明, 1969年鱼类引入后象鼻溞的壳长、壳刺长度、触角长度显著减小, 反映了鱼类捕食压力上升的影响. 本研究进一步揭示了水文调控和鱼类引入对湖泊环境和生物群落结构的驱动影响. 其中, 1960s以前云龙天池处于自然波动的状态, 湖泊环境和枝角类群落变化主要受气候(如降水、气温)的影响; 1960s以来人类活动的影响强度已经掩盖了气候变化的信号, 成为影响湖泊生态演化轨迹的主要因素. 为了开展有效的湖泊保护与生态治理, 有必要综合评估水文调控、鱼类引入等人类活动对湖泊生态健康的长期影响. 相似文献
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滇池生态系统退化成因、格局特征与分区分步恢复策略 总被引：5，自引：3，他引：2
选取生态系统中重要的组成成份:浮游植物、底栖动物、水生植物的历史演变和现在分布状况数据,结合水质变化情况,揭示了滇池生态系统退化原因:在外因上,污染物持续输入以及围湖造田、直立堤岸和水量交换缓慢等外力干扰加剧系统组分失衡是直接原因;在内因上,由于滇池所处的地理位置、气候等原因,蓝藻生物量对营养盐增加的响应远高于其他湖泊(太湖、巢湖),草型向藻型湖泊的转换进程更快;与太湖和东湖的生态系统比较,高原湖泊滇池生态系统相对脆弱,如物种的同域分化、窄生态位,导致系统的稳定性差、自我修复能力弱.通过对滇池生态格局特征、湖岸带结构的分析,将滇池划分为5个生态区:草海重污染区、藻类聚集区、沉水植被残存区、近岸带受损区和水生植被受损区,并提出"五区三步,南北并进,重点突破,治理与修复相结合"的滇池生态系统分区分步治理的新策略和"南部优先恢复;北部控藻治污;西部自然保护;东部外围突破"的总体方案. 相似文献
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The Mississippi River Valley Alluvial Aquifer ranks among the most overdrafted aquifers in the United States due to intensive irrigation. Concern over declining water levels has increased focus on understanding the sources of recharge. Numerous oxbow lakes overlie the aquifer that are often considered hydraulically disconnected from the groundwater system due to fine-grained bottom sediments. In the current study, groundwater levels in and around a 445-ha oxbow lake-wetland in Mississippi were monitored for a 2-year period that included an unusually long low-water condition in the lake (>17 months), followed by a high-water event lasting over 4 months before returning to earlier low-water levels. The high-water pulse (>4 m rise) provided a unique opportunity to track the impact in the underlying alluvial aquifer. During low-water conditions, groundwater flowed westward beneath the lake. Following the lake rise, groundwater beneath and near the perimeter responded as quickly as the same day, with more delayed responses moving away from the lake. Within 2 months, a groundwater mound formed near the centre of the oxbow (>3 m increase), with a reversal in the local hydraulic gradient towards the east. Flow returned to a westward gradient when the lake level dropped back below 0.3 m. Analysis of precipitation and nearby river stage could not account for the observed behavior. Recharge to the aquifer is attributed to rising water levels spreading over point bar deposits and into the surrounding forested wetlands where preferential flow pathways are likely to exist due to buried and decomposing tree remains. An earlier study in the wetland demonstrated an increasing redox potential in isolated zones, consistent with the existence of preferential flow pathways through the bottom sediments (Lahiri & Davidson, 2020). Retaining high-water levels in oxbow lakes could be a relatively low-cost water management practice for enhancing aquifer recharge. 相似文献
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19882016年洞庭湖大型底栖动物群落变化及驱动因素分析 总被引：1，自引：0，他引：1
洞庭湖是我国第二大淡水湖泊,其水文条件对湖泊湿地生态系统健康的维系发挥着不可替代的作用.近年来,水环境恶化日益威胁湖区水生态系统健康.然而,有关底栖动物水生态健康评价的研究仍然停留在物种群落结构方面,缺乏底栖动物群落功能对水污染响应的研究,尤其在较长时间尺度上.因而,本研究分析了19882016年近30 a来洞庭湖的水质和底栖动物群落数据,探寻底栖动物群落功能对水环境恶化的响应规律.结果表明,洞庭湖水体总氮浓度是威胁底栖动物物种和功能群落变动的主要因素.此外,不断恶化的水环境驱动底栖动物物种和功能群落结构改变,表现为敏感水生昆虫的比例下降,寡毛类、小型软体动物比例的上升,并伴随着体长为1.00~1.99 cm、背扁型、侧扁型、不移动等功能性状类别比例的下降.同时,水环境恶化降低物种丰富度、功能丰富度和劳氏二次熵多样性.基于距离的冗余分析结果显示,水体氮营养盐、重金属离子和有机污染物共同驱动底栖动物物种群落结构的变异,而营养盐类与无/有机污染物决定着其功能群落结构的变异.鉴于洞庭湖水质不断恶化的状况,本研究建议采取一系列措施,包括合理管控湖区周边废水直排入湖、取缔湖区内的非法采砂以及调控枯水季洞庭湖水位等.生物监测和评价方面,建议将底栖动物物种和功能群落一并纳入评价体系,且优先选用物种丰富度、功能丰富度和劳氏二次熵指数评估换水周期较短的大型浅水湖泊水质变化对底栖动物物种和功能多样性的影响. 相似文献
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苏北骆马湖大型底栖动物群落结构及水质评价 总被引：2，自引：1，他引：1
2014年1-12月,对苏北骆马湖水质和大型底栖动物进行了逐月调查.根据湖区的生境特征将骆马湖划分为3个区域:采砂区域、植被区域和其他区域.对比分析不同区域水质参数和底栖动物群落结构,并利用《地表水环境质量标准》(GB 3838-2002)、综合营养状态指数和生物学指数对水质进行评价.结果表明,采砂区域的水深显著高于植被区域,而透明度显著低于另外两个区域;采砂区域的总氮、总磷、硝态氮和正磷酸盐浓度均显著高于植被区域,生物多样性显著低于另外两个区域.骆马湖内共采集到大型底栖动物41种,其中环节动物8种,软体动物15种,节肢动物18种.铜锈环棱螺(Bellamya aeruginosa)、苏氏尾鳃蚓(Branchiura sowerbyi)、霍甫水丝蚓(Limnodrilus hoffmeisteri)、长角涵螺(Alocinma longicornis)是现阶段的优势种.10个监测点底栖动物的年均密度和年均生物量分别为77.19±43.59 ind./m~2和37.62±28.31 g/m~2,呈现出较高的空间异质性.生物量较密度空间差异更大,生物量在湖泊四周的监测点较高,而在湖心开阔水域较低.水质评价结果表明骆马湖水质处于中营养状态,总体属于中度污染,作为南水北调东线工程重要的调蓄湖泊以及饮用水源地和水产养殖基地,加强水环境保护不容懈怠. 相似文献
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Ifigenia Kagalou Georgios Economidis Ioannis Leonardos Constantinos Papaloukas 《Limnologica》2006,36(4):269-278
Macroinvertebrates play a key role in freshwater lentic and lotic ecosystems. The macroinvertebrate benthic community of a shallow Mediterranean lake (Lake Pamvotis, NW Greece) was studied. The benthic assemblage was sampled monthly at five sites during a period of 1 year (Apr. 1998–Mar. 1999). In addition hypolimnetic water quality variables were monitored over the same period at each site.
The aim of the study was (a) to describe the intra-annual and spatial variability in benthic communities, (b) to relate possible community changes to environmental conditions and (c) to evaluate the responses of the lake's ecological status on community indices.
The benthic fauna of Lake Pamvotis was found to be very limited with a total of 10 species belonging to five taxonomic groups. The oligochaete community comprised 80% of the total benthic fauna with Potamothrix bavaricus as a new record for the Lake Pamvotis and Potamothrix hammoniensis, being the dominant benthic species represented more than 61% of the total benthic fauna. Chironomus plumosus was the most abundant chironomid species contributing with about 6% of the total benthic fauna, and Chaoborus flavicans with 19% was the important dipteran. Almost all benthic species showed the same intra-annual seasonal pattern, with peak population densities during spring and early summer except P. hammoniensis which predominated during the whole sampling period. Dissolved oxygen and temperature seemed to be the main environmental factors affecting community indices.
Benthic communities are affected by human disturbances in Lake Pamvotis shifting their composition to more tolerant taxa, reflecting also the eutrophic to hypertophic character of the lake. 相似文献
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滇池东北部沿岸带生态修复技术研究及工程示范——环境恶化、生态退化现状及其成因 总被引：4，自引：2，他引：2
本文作为“滇池沿岸带生态修复技术研究及工程示范”系列研究论文之一,主要研究了滇池东北部沿岸带环境恶化与生态退化现状、成因及妨碍自然生态恢复的主要限制因素．风浪强烈侵蚀、湖底坚硬贫瘠、水质严重污染、大型水生植物和底栖动物消失,滇池东北部沿岸带已经蜕变成了“水域荒漠”．湖滩湿地围垦、人工岸堤修建和水质污染是导致沿岸带环境恶化、生态退化的主要原因,强烈的风浪冲刷和严重的水质污染是阻碍沿岸带自然生态恢复的主要限制因素．生态恢复必须从基础环境改造入手,实施生态修复． 相似文献
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江湖联通状况对湖泊生态系统有着重要影响,但是由于缺乏长期的生态水文监测数据,湖泊系统对其响应的过程与机理仍缺乏认识.本研究选择长江中下游地区典型湖泊——涨渡湖,结合该湖一沉积短柱的210Pb、137Cs年代测试,通过高分辨率的多指标分析(硅藻、元素地球化学和粒度),揭示近200年来湖泊生态系统对该湖与长江之间联通关系改变的响应过程.与历史文献记载一致,古湖沼学记录揭示出该湖与长江的联通状况经历了3个阶段.1)江湖联通期(1954年以前):该湖与长江自然相通,江湖水体交换频繁,丰富的贫营养浮游种Cyclotella bodanica表明该湖长期处于低营养及湖泊水位相对较高的状态.2)江湖隔绝期(1954 2005年):随着湖坝的兴建,江湖联通关系被隔绝,湖泊换水周期变长,透明度降低,喜好扰动环境的Aulacoseria granulata大量生长.相应地,富营养硅藻的增加、高TOC含量以及较高的沉积物TP、TN浓度表明,该湖营养水平逐渐升高.特别是近20年来,较高含量的富营养硅藻种——C.meneghinena、A.alpigena、Nitzschia palea、Surirella minuta和地球化学记录,包括TOC含量和沉积物TP、TN浓度,表明该湖富营养化程度加剧.3)江湖季节性联通期(2005年后):硅藻以附生种、底栖种为主,但仍有一定含量的富营养化属种,且TOC含量以及沉积物TP、TN浓度仍然保持较高水平,表明富营养程度有所缓解.古湖沼学和历史记录都揭示了自该湖与长江无连通后其生态状况的快速退化、重新联通后生态状况有所好转.因此,在长江中下游洪泛平原区,江湖关系的重新联通将是减轻湖泊生态压力的有效手段. 相似文献
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Jochen Schaumburg Christine Schranz Gabriele Hofmann Doris Stelzer Susanne Schneider Ursula Schmedtje 《Limnologica》2004,34(4):302-314
A new assessment system for macrophytes and phytobenthos in German lakes according to the Water Framework Directive of the European Community is described. Based on biological, chemical and hydromorphological data from about 100 lake sites covering the main ecoregions, hydromorphological lake types and degradation forms, biocoenotic types could be defined. For developing a classification system the quality element macrophytes and phytobenthos was divided into two components: macrophytes and benthic diatoms. For macrophytes 4 and for benthic diatoms 4 lake types were identified. The benthic vegetation at reference conditions is described and degradation is characterised as deviation in benthic vegetation species composition and abundance from the reference biocoenosis. For classification in five ecological status classes, several metrics were developed and used in combination with existing indices. For a few of the described lake types further investigations are necessary before a classification can be developed. 相似文献
14.
太湖河湖水系连通需求评价初探 总被引：3，自引：2，他引：1
水系连通需求分析是河湖水系连通战略研究的重要内容.水系连通需求指人类社会经济发展对水资源调配、防洪排涝、改善生态环境等方面的需求及对河湖水系健康的维护,它源于水系能够提供各种水生态系统服务功能的生态学特性.通过分析水系连通需求、水生态系统服务功能和水系连通工程之间的内在关系,认为水系连通需求评价可转化为对水生态系统服务功能的评价.运用水当量评价方法,建立了河湖水系连通需求评价的方法体系,并以河网地区的典型代表——太湖为例,定量评价了太湖在水资源调配、调蓄洪水、水环境净化和维持生境等方面的连通需求.结果表明,太湖水系年均连通需求最大的是净化入湖废污水需水量,其次为水资源调配需水量,而太湖调蓄洪水的需求减少;湖水自身净化需水量较大,且为一次性需水.水环境净化的需求需要通过降低污染物入湖量,进行湖泊生态修复等主要措施以及引清水增加环境容量这一辅助连通措施共同完成.水系连通需求的定量评价可为水系连通战略及工程的规划设计提供理论基础. 相似文献
15.
五里湖富营养化过程中水生生物及生态环境的演变 总被引：15，自引：1，他引：14
五里湖是太湖西北部一个小型浅水湖湾,是无锡市的饮用水源和主要风景游览区。50年代时,该湖基本保持着原始状态,全湖以大型水生植物占优势。湖水清澈见底,水质为中营养水平,溶氧接近饱和,对外来的N、P污染冲击具有很强的缓冲能力。底泥的氧化程度较高,磷和有机物含量仅为0.023％和0.75％。浮游藻类受到了大型水生植物的强烈抑制,年均数量为26.7×10~4个/L,以硅藻和隐藻为主;从春季至秋季,随着大型水生植物的增长,浮游藻类数量大幅度减少。浮游动物多达190种,年均数量为5660ind./L。大型底栖动物较多,以日本沼虾和螺、蚌类为主。鱼类资源十分丰富,63种鱼中以凶猛性鱼类占优势,并有较多的底栖性鱼类。 自50年代以来,大约有1/2的湖面被围垦,沿岸带生态条件被破坏,失去了最适合于大型水生植物生长的浅水区。加之60年代后期在全湖放养草鱼,水生植被遭到彻底毁灭。外源污染加剧,引起了水质的严重富营养化。围垦和修建水闸隔断了五里湖与太湖间的通道,限制了两个水体间的水流交换,妨碍了污染物的稀释扩散,使得来自无锡市区的污水成了五里湖的主要补给水源,加速了富营养化的进程。五里湖水质已达重富营养水平,透明度小于0.5m,缺氧较为严重。营养物在底泥中大量积累,TP和TOC含量分别增高了4.17倍和1.87倍。在春末 相似文献
16.
《Limnologica》2016
Biological communities in shallow lakes are often subject to the combined effects of eutrophication and wind-wave disturbance. However, their relative importance in regulating macrozoobenthic community assembly has not been well addressed. In the present study, a monthly sampling of macrozoobenthos and environmental parameters was conducted at ten sites from December 2012 to November 2013 in Lake Hongze, the fourth largest freshwater lake in China, which has undergone serious water quality deterioration over the past few decades. A total of 30 taxa were recorded during the 12 sampling occasions, including 6 chironomids, 6 bivalves, 4 gastropods, 4 oligochaetes, 4 polychaetes, 4 crustaceans and 2 other aquatic insects. The mean abundance and biomass of total macrozoobenthos varied greatly among the ten sites and presented distinctive taxonomic composition between the protected bays and the offshore zone. Three eutrophication parameters (including permanganate index (CODMn), chlorophyll a, and total phosphorus in surficial sediments) and three wind-wave variables (including Secchi depth, turbidity, and mean effective fetch) were highly related to spatial variation of macrozoobenthic assemblages. When eutrophication variables were controlled, there was a significant correlation between community similarity and wind-wave disturbance condition, and vice versa. Variation partitioning showed that wind wave disturbance explained 15.9% of the variation in benthic community composition, slightly lower than that explained by eutrophication (17.9%). These results indicate that wind-wave disturbance is as important as eutrophication in regulating benthic community structure in this large shallow lake. Wind-wave disturbance imposed opposite effects on benthic community relative to eutrophication, and were more prominent in the offshore zone weakening the role of eutrophication. 相似文献
17.
太湖东部不同类型湖区底泥疏浚的生态效应 总被引：9，自引：1，他引：8
为研究底泥生态疏浚对太湖东部不同类型湖区水生生态系统的影响,2012年8月于东太湖养殖湖区和胥口湾草型湖区采集沉积物和生物样品,分析疏浚对底泥污染控制、水质改善以及各生物群落结构的影响.结果表明,底泥疏浚能有效去除表层沉积物中的营养物质,降低底泥重金属含量及其潜在生态风险,但底泥疏浚对不同类型湖区水质和生物群落结构的影响存在明显差别.在富营养化较严重的东太湖养殖湖区,底泥疏浚达到了一定的改善水质的效果,浮游植物密度、生物量均不同程度降低,且群落中蓝藻所占比例下降;水生植物和底栖动物群落也在较短时间内得到恢复;胥口湾草型湖区的底泥疏浚则破坏了原先良好的水生植物群落,造成湖区整体水质下降,各主要生物类群的恢复相对缓慢. 相似文献
18.
草型湖泊和藻型湖泊中大型底栖动物群落结构的比较 总被引：12，自引：6，他引：6
系统地比较了草型湖泊扁担塘与藻型湖泊后湖大型底栖动物的群落结构.结果表明,草型湖泊扁担塘的物种种类、物种多样性、密度和生物量均较藻型湖泊后湖的为高.两湖在物种组成和功能摄食群上存在极大差异,相似性系数为0.3左右,草型湖泊的大型底栖动物主要以刮食者数量为多,而藻型湖泊主要以收集者的为多.这说明水生高等植物对于维持湖泊生态系统中大型底栖动物多样性方面起着非常重要的作用,也是维持湖泊生态系统结构复杂性、空间异质性和功能稳定性的重要因素. 相似文献
19.
Surface water oxygen and hydrogen isotopic values are commonly used as proxies of precipitation isotopic values to track modern hydrologic processes while proxies of water isotopic values preserved in lake and river sediments are used for paleoclimate and paleoaltimetry studies. Previous work has been able to explain variability in USA river‐water and meteoric‐precipitation oxygen isotope variability with geographic variables. These studies show that in the western United States, river‐water isotopic values are depleted relative to precipitation values. In comparison, the controls on lake‐water isotopic values are not well constrained. It has been documented that western United States lake‐water input values, unlike river water, reflect the monthly weighted mean isotopic value of precipitation. To understand the differing controls on lake‐ and river‐water isotopic values in the western United States, we examine the seasonal distribution of precipitation, evaporation and snowmelt across a range of seasonality regimes. We generate new predictive equations based on easily measured factors for western United States lake‐water, which are able to explain 69–63% of the variability in lake‐water hydrogen and oxygen isotopic values. In addition to the geographic factors that can explain river and precipitation values, lake‐water isotopic values need factors related to local hydrologic and climatic characteristics to explain variability. Study results suggest that the spring snowmelt runs off the landscape via rivers and streams, depleting river and stream‐water isotopic values. By contrast, lakes receive seasonal contributions of precipitation in proportion to the seasonal fraction of total annual precipitation within their watershed. Climate change may alter the ratio of snow to rain fall, affecting water resource partitioning between rivers and lakes and by implication of groundwater. Paleolimnological studies must account for the multiple drivers of water isotopic values; likewise, studies based on the isotopic composition of fossil material need to distinguish between species that are associated with rivers versus lakes. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
20.
水位变化对河流、湖泊湿地植被的影响 总被引：12，自引：6，他引：6
水位是湿地生态水文过程的关键因素之一,其改变将影响湿地植被覆盖度和物种组成,最终产生群落演替.从水位梯度,水位波动和人工控湖、控河工程3方面论述水位变化对湿地植被的影响:由于对水位选择的不同及彼此竞争力的差异,湿地植物种沿水位具有梯度分布现象,同时形态可塑性能对其分布范围产生一定影响;水位波动的频率和淹没持续时间对于植被演替具有基础性的作用,水位波动幅度的影响则相对较小,周期性波动能维持以草本植物为主的湿地植被的物种多样性和稳定性,非周期性波动以洪水、干旱为主,易促进湿地植被向固定的水生或陆生方向演替;人工控湖、控河的影响在机理上并无特殊之处,但保证物种多样性和生态系统稳定性的各种缓解措施具有较高的参考价值.基于机理的量化模型,自然、人为因素驱动下水位变化对湿地植被影响的差别研究,模拟水位波动实验以及人工控湖、控河工程的跟踪观测将是今后该领域研究的热点. 相似文献