文峪河上游河岸林群落类型及其生态适应性

以文峪河上游河岸林为研究对象,采用TWINSPAN法对研究地区河岸林进行群落分类,对各群落类型特征进行分析.在提出河岸林群落生态功能适应性指标的基础上,对研究地区河岸林群落进行生态功能适应性分组.通过研究,文峪河上游河岸林可划分为阔叶混交林、华北落叶松阔叶混交林、云杉落叶松混交林、云杉阔叶混交林、阔针混交林、油松阔叶混交林、青杨林、沙棘灌丛和柳树灌丛等9个群落类型,但群落类型之间的分异性总体表现不高,且表现出突出的多样性特征;群落乔木层和灌木层的物种组成复杂,草本层多为一些耐干扰种和耐水湿种,总体上越远离河岸,高地群落中的物种比例越高,表现出高地森林与河流之间生态过渡带的典型特点和河岸带生态环境的高度异质性;根据本文构建的群落的生态功能适应性指标,研究地区9个河岸林群落类型可以划分为强入侵性功能组、中等入侵性功能组、弱入侵性功能组和高逃避性功能组等4个生态适应性功能组,不同生态适应性功能组的群落中,乔木层和灌木层的主要物种具有明显不同的生态对策,而草本层物种的差异不明显.     

受损河岸生态修复工程的土壤生物学评价

为探索受损河岸生态修复的理论与技术,以修复4年的河岸生态修复工程为研究对象,从土壤生物学角度评价了人工构建的河岸生境缀块对受损河岸生态系统的修复作用.结果表明,经过4年的恢复,修复区土壤中各种微生物的数量明显高于对照区;修复区土壤动物种类、数量、生物多样性指数以及土壤有机质、N、P、K含量均高于对照区.修复后,受损河岸的土壤性状得到了明显改善,土壤生物多样性及河岸生态系统稳定性得到了提高.人工构建生境缀块的河岸生态修复工程不仅经济成本低,而且具有生态、景观和社会价值,为已建混凝土河岸的生态改造和受损河岸的近自然修复提供了新模式.     

东苕溪中下游河岸类型对鱼类多样性的影响

河流修复工程被美国《科学》杂志列入2000年最具发展潜力的六大领域之一,河流修复工程对水生生态系统的影响也成为各国科学家的研究热点。本文以东苕溪中下游河段为对象,研究4种不同河岸类型（自然河岸 水生植物（A）、自然河岸 无水生植物（B）、人工河岸 水生植物（C）、人工河岸 无水生植物（D））对鱼类生物多样性的影响。本次调查共采集鱼类标本499尾,经鉴定为32种,隶属于7目10科24属。鱼类生物多样性结果显示A、B的物种丰度和Shannon-Wiener指数与D存在显著差异（P<0.05）; A的优势度指数与D存在显著性差异（P<0.05）; A、C的均匀度与D存在显著性差异。鱼类群落NMDS排序与相似性分析（ANOSIM）显示D与A、B、C能完全分开,且D与A、C存在显著性差异（P<0.05）,其中A与C存在显著性差异。因此,河流修复工程中水生植被的恢复对于水生生物多样性的维持至关重要,且恢复水生植被的河流修复工程会减少该工程对鱼类群落结构和生物多样的负面影响。     

城市河流改造工程对河流生态系统野生维管植物的影响

随着城市化的发展,许多城市对流经市区的河流进行了大规模工程改造,在获得了多种效益的同时,也引起了诸如生物多样性破坏和物种组成改变等一系列生态问题,因此对城市河流改造工程的生态影响进行研究非常重要,将有助于在未来城市河流改造中更有效地保护河流生态系统。该文以汾河太原段的河道改造工程为研究对象,用Shannon-Weiner 多样性指数、Sørensen群落相似性指数和单因素方差分析方法,研究了河流改造工程对河流生态系统中的野生维管植物物种多样性、频度和群落物种组成相似性的影响。结果表明:太原汾河段改造后比改造前的野生维管植物物种数和Shannon-Weiner 多样性指数显著降低;低频度的物种数明显增加而高频度的物种数明显减少;河流改造前后的群落相似性明显降低。由此可见,城市河流改造工程对河流生态系统中的野生维管植物物种多样性、频度和群落相似性有明显影响。     

水电开发对河岸植被影响研究进展

河岸植被是河流生态系统的重要组成部分, 在维持河流生态系统完整性和河岸生物多样性保护方面具有重要作用。目前, 水电开发影响下河岸植被的物种组成、多样性、种间关联等几方面日益受到关注, 是河流生态学研究中的重要热点。文章阐述了水电开发后河流水文、河岸生境、繁殖体扩散、外来物种入侵等影响下河岸植被的响应机制。探讨了河岸植被与生态环境的相关性, 提出了今后河岸植被与水电开发相互作用机制, 及水电开发的正负生态效应综合影响研究。     

土壤生物工程减少坡面侵蚀效果

土壤生物工程的构建是存在一定的目的性的,包括使河流边坡保持长期有效的稳定性,使遭遇破坏的生态环境能够得到有效恢复等。与此同时对于土壤生物工程的构建,需要在稳定土壤为前提条件,这样才能够保证此项生物工程在构建方面的完善。本课题结合具体工程项目,重点对土壤生物工程减少坡面侵蚀效果进行了探究,希望以此为土壤生物工程的合理构建提供依据。     

黑河下游分水后的植被变化初步研究

黑河下游地区近年来由于河水注入量的持续减少,使得依赖河水补给的地下水相应减少,造成区域性地下水位下降,从而出现了一系列的生态环境问题,大面积湿地消失,天然植被全面衰败,土地盐化加剧,胡杨和沙枣林面积减少,并以老林为主,红柳灌丛也减少,并且多已成为稀疏矮化的群落。各种禾草草甸严重退化,多以演替成苦豆子群落。为了恢复和重建受损的下游生态系统,2000年7月开始,实施了黑河下游应急生态输水工程,水流于2002年7月17日流进黑河尾闾端的东、西居延海,使干涸10年的居延海重新受到水的滋润。作者根据近三年黑河下游分水前后地下水位和植被等项内容的监测资料,探讨了地下水位与天然植被生长的相互关系。研究结果表明：分水使得该地区生态环境有了较大的改善,地下水位普遍抬升,胡杨林得到恢复,灌木荒漠植被得到部分恢复,禾草草甸植被得到一定程度的恢复。     

文峪河上游河岸林群落环境梯度格局和演替过程

以文峪河上游河岸林为研究对象,通过对群落建群种的DCA排序和物种关联分析进行生态种组划分,阐明了河岸林群落建群种各生态种组之间的生态演替功能差异,结合对样地和生态适应性功能组的DCA排序结果,分析了河岸林群落空间分布的环境梯度格局及其影响因素,基于以上分析,构建了研究地区河岸林群落演替过程,揭示了环境梯度格局对河岸林群落演替的控制作用。通过研究,文峪河上游河岸林群落生态适应性功能组比群落在排序空间上具有更好的分异性,采用生态适应性功能组更有利于分析群落的时空关系;研究地区河岸林群落9个建群种划分为阳性喜湿先锋型、阳性中生演替型、耐阴喜湿演替后期型和阳性中生逃避型4个生态种组;研究地区海拔梯度、河岸带坡度和河谷型共同决定了河岸林群落的分布格局,河岸带坡度和河谷型实际反映的是河岸带水文状况对河岸林群落时空格局的控制作用;根据生态适应性功能组和生态种组构建了研究地区河岸林群落演替模型,不同的海拔及其相应的河谷型具有明显不同的演替过程。     

草型富营养化湖泊生态恢复工程技术的研究--内蒙古乌梁素海生态恢复工程试验研究

在典型草型富营养化湖泊-内蒙古乌梁素海设立试验研究基地,进行较大规模生态恢复工程试验,研究表明,实施沉水植物收割工程与芦苇园田化生态管理工程是草型富营养化湖泊生态恢复的两项重要技术措施。以机械化方式收割沉水植物能够削减湖泊内源性营养物负荷的积累和释放,减少二次污染,抑制生物填平作用,改善水体环境;采用机械化技术控制芦苇蔓延、打开芦苇区通风道和通水道,可以重建湖泊绿色自然景观,提高全湖水流循环速度。有计划、合理地运用生态恢复工程不仅可以减轻草型湖泊所面临的巨大生态压力,延缓沼泽化演化进程。而且可以在实施生态工程的同时开发利用水生植物资源,使湖泊环境与湿地综合利用得到持续发展。     

塔里木荒漠河岸林不同生境群落物种多度分布格局

为解释塔里木荒漠河岸林群落构建和物种多度分布格局形成的机理, 本文以塔里木荒漠河岸林2个不同生境(沙地、河漫滩) 4 ha固定监测样地为研究对象, 基于两样地物种调查数据, 采用统计模型(对数级数模型、对数正态模型、泊松对数正态分布模型、Weibull分布模型)、生态位模型(生态位优先占领模型、断棍模型)和中性理论模型(复合群落零和多项式模型、Volkov模型)拟合荒漠河岸林群落物种多度分布, 并用K-S检验与赤池信息准则(AIC)筛选最优拟合模型。结果表明: (1)随生境恶化(土壤水分降低), 植物物种多度分布曲线变化减小, 群落物种多样性、多度和群落盖度降低, 常见种数减少。(2)选用的3类模型均可拟合荒漠河岸林不同生境群落物种多度分布格局, 统计模型和中性理论模型拟合效果均优于生态位模型。复合群落零和多项式模型对远离河岸的干旱沙地生境拟合效果最好; 对数正态模型和泊松对数正态模型对洪水漫溢的河漫滩生境拟合效果最优; 中性理论模型与统计模型无显著差异。初步推断中性过程在荒漠河岸林群落构建中发挥着主导作用, 但模型拟合结果只能作为推断群落构建过程的必要非充分条件, 不能排除生态位过程的潜在作用。     

Waste Not,Want Not: The Need to Utilize Existing Artificial Structures for Habitat Improvement Along Urban Rivers

Urban rivers have often experienced substantial engineering modification and consequently are highly degraded aquatic ecosystems with minimal riparian habitat. Habitat restoration and improvement efforts are needed within urban rivers to support ecological communities and increase ecosystem integrity. Most river restoration techniques are not feasible within large urban rivers, and so there is a need to develop novel methodologies. Artificial structures such as river walls can function as habitat for plant and invertebrate species in urban rivers, and in some cases can be more diverse than remnant habitat. Along the River Thames through central London, plant species richness was found to be significantly higher on river walls than intertidal foreshore, which represents the only remnant habitat for riparian species. Both this survey and other studies have suggested that the physical and environmental characteristics of river walls are likely to influence their capacity to function as ecological habitat, for example, walls composed of more complex construction materials (brick and boulders) being more diverse than simpler structures (concrete and sheet piling). The opportunity exists to use river walls and other artificial structures (e.g., jetties) to improve habitat along urban rivers by installing walls which are designed to be more complex, or by adding modifications to existing walls. Some trial modifications, such as the addition of wall ledges and timber fenders to sheet piling, have been installed at Deptford Creek along the River Thames, and have so far greatly supported the colonization and development of plant communities. The restoration possibilities of such modifications should be considered, and further development and rigorous testing of installations is required in urban rivers to make sound restoration recommendations.     

河岸无脊椎动物多样性维持机制研究进展

河岸是河流与陆地之间重要的生态界面,生物多样性丰富,但受到人为活动的严重威胁。无脊椎动物在河岸生物多样性中占有重要地位,发挥着非常重要的生态功能,也是水生生态系统和陆地生态系统之间物质和能量联系的重要纽带。尽管已有很多学者对河岸无脊椎动物群落进行了研究,但缺乏对河岸无脊椎动物多样性维持机制的总结。本文结合洪水和干旱、营养物质、微生境多样性、河岸植被、微气候梯度、食物资源以及河流空间梯度等影响因素,初步讨论和归纳了河岸无脊椎动物多样性的维持机制。周期性洪水和干旱引发了无脊椎动物的繁殖和迁移等行为,增加了河岸无脊椎动物群落周转率,为无脊椎动物创造了理想的条件。充足的营养物质使河岸具有较高的初级生产力,支撑了较高的无脊椎动物多样性。较高的微生境多样性为无脊椎动物提供了多样的生态位空间,孕育了特殊的河岸无脊椎动物种类。复杂的河岸植物群落不但是河岸无脊椎动物的食物来源之一,也为河岸无脊椎动物提供了多样的生态位空间和重要的避难场所。微气候环境的空间分异提供了复杂多样的生境条件,为水生无脊椎动物和陆生无脊椎动物种类在河岸共存创造了条件。跨越界面的资源补给增加了河岸无脊椎动物的食物可利用率,为河岸无脊椎动物提供了特殊的食物来源。这些因素在空间上呈现出明显的纵向梯度和侧向梯度,从更大尺度上为河岸无脊椎动物的多样化提供了条件。因此,探讨河岸无脊椎动物多样性的维持机制对于河岸生物多样性保护以及河流生态系统综合管理具有重要的指导意义。     

河岸带研究及其退化生态系统的恢复与重建

河岸带是指水陆交界处的两边,直至河水影响消失为止的地带。河岸带是湿地的重要组成部分,在流域生态系统中发挥着重要的作用,具有较大的生态、社会、经济和旅游价值。河岸带研究以生态学、水文学和地貌学炎基础,涉及多种学科和技术方法。由于自然和人为因素的影响,退化河岸带的生态恢复与重建较为复杂,通过安徽潜山县潜水退化河岸带滩地近6a的生态恢复与重建试验,研究结果表明：恢复与重建后的河岸带滩地生态系统的生物多样性和稳定性增加;土训结构和养分条件得到改善,其中,小于0.002mm的粘粒含量的平均值由恢复前的4.53％,上升到恢复后的11.71％,土壤容重由恢复前的1.455g/cm^2下降到恢复后的1.2g/cm^2,土壤有机质的平均值由恢复前的1.25g/kg上升到恢复后的9.44g/kg;河滩地泥沙淤积量增加;植物抗风浪作用增强,有效地保护了河岸,改善了河岸带地区的小气候。河岸带研究在我国起步较晚,因此,今后应加强河岸带的管理和对退化河岸带生态系统的恢复与重建工作,使河岸带生态系统可持续地为人类提供丰富多样的生产、生活和观光旅游产品。     

Integrating and extending ecological river assessment: Concept and test with two restoration projects

While the number of river restoration projects is increasing, studies on their success or failure relative to expectations are still rare. Only a few decision support methodologies and integrative methods for evaluating the ecological status of rivers are used in river restoration projects, thereby limiting informed management decisions in restoration planning as well as success control. Moreover, studies quantifying river restoration effects are often based on the assessment of a single organism group, and the effects on terrestrial communities are often neglected. In addition, potential effects of water quality or hydrological degradation are often not considered for the evaluation of restoration projects.We used multi-attribute value theory to re-formulate an existing river assessment protocol and extend it to a more comprehensive, integrated ecological assessment program. We considered habitat conditions, water quality regarding nutrients, micropollutants and heavy metals, and five instream and terrestrial organism groups (fish, benthic invertebrates, aquatic vegetation, ground beetles and riparian vegetation). The physical, chemical and biological states of the rivers were assessed separately and combined to value the overall ecological state.The assessment procedure was then applied to restored and unrestored sites at two Swiss rivers to test its feasibility in quantifying the effect of river restoration. Uncertainty in observations was taken into account and propagated through the assessment framework to evaluate the significance of differences between the ecological states of restored and unrestored reaches. In the restored sites, we measured a higher width variability of the river, as well as a higher width of the riparian zone and a higher richness of organism groups. According to the ecological assessment, the river morphology and the biological states were significantly better at the restored sites, with the largest differences detected for ground beetles and fish communities, followed by benthic invertebrates and riparian vegetation. The state of the aquatic vegetation was slightly lower at the restored sites. According to our assessment, the presence of invasive plant species counteracted the potential ecological gain. Water quality could be a causal factor contributing to the absence of larger improvements.Overall, we found significantly better biological and physical states, and integrated ecological states at the restored sites. Even in the absence of comprehensive before-after data, based on the similarity of the reaches before restoration and mechanistic biological knowledge, this can be safely interpreted as a causal consequence of restoration. An integrative perspective across aquatic and riparian organism groups was important to assess the biological effects, because organism groups responded differently to restoration. In addition, the potential deteriorating effect of water quality demonstrates the importance of integrated planning for the reduction of morphological, water quality and hydrological degradation.     

Gallery Forest or Herbaceous Wetland? The Need for Multi‐Target Perspectives in Riparian Restoration Planning

Much riparian restoration focuses on establishment of gallery forests, with relatively limited effort to restore herbaceous wetlands as key components of riparian landscape mosaics. Multiple reasons for this include inherent cultural or esthetic preferences, greater availability of scientific knowledge to support riparian forest restoration, and choices of ecological indicators commonly used for monitoring and assessment. Yet riparian herbaceous wetlands have declined dramatically as a result of river regulation and agricultural development, leading to losses of important habitats and ecosystem services that differ from those provided by gallery forests. As an alternative to a single‐minded focus on tree establishment, we advocate restoration of diverse and dynamic habitat mosaics in the context of natural variability of flow and sediment regimes. Landscape context should inform active restoration activities at the local scale, such that riparian forests are not planted in ecologically inappropriate sites. Models are needed to match life history requirements of particular wetland herbaceous plant species with details of flow and sediment transport regimes. We emphasize the importance of herbaceous wetlands as a critical and often overlooked component of riparian ecosystems, and the need for both passive and active restoration of fluvial marshes, sloughs, wet meadows, alkali meadows, off‐channel ephemeral ponds, and other critical floodplain communities associated with herbaceous plant dominance.     

Managing riparian zones for river health improvement: an integrated approach

Riparian zones are among the most valuable ecosystems on the earth. They act as the ecological engineers that improve river health through delivering a range of ecosystem functions. Stream bank stabilization, pollutant and sediment buffering, temperature regulation, provision of energy to river food webs and communities, groundwater recharge and provision of ecological corridors and habitat for wildlife, are among major ecosystem functions of riparian zones that play a great role in river health. Besides these ecosystem functions, riparian zones also provide various ecosystem goods and services for human well-being. But in the current scenario, riparian zones are under severe threat due to agricultural activities, urbanization, river flow alteration, overexploitation, climate change, pollution, and biological invasion. In the present and probable future scenarios of declining river health and global environmental changes, there is a pressing need of an integrated approach for managing riparian zones. This review article aims to advocate an integrated approach for riparian zone management based on various components such as riparian condition assessment, policy framework, stakeholder’s participation, management practices, legislation, and awareness. Authors also discussed riparian zones in context of their concepts, features, functions, and threats.

     

The shore vegetation in selected lakeland areas in northeastern Poland

Phytosociological and habitat studies on the riparian vegetation in the river-lake systems of Krutynia River and upper Szeszupa River (north-eastern Poland) typical of the postglacial lakelands, were conducted. It was demonstrated that the riparian vegetation is composed of communities from the classes: Phragmitetea, Scheuchzerio-Caricetea fuscae, Artemisietea, Molinio-Arrhenatheretea, Alnetea glutinosae and Querco-Fagetea. In the land/water ecotone, these communities are spatially differentiated and often from a zonal pattern. In the waters from the rhizome-root layer (pore waters), the differences in nutrient concentration on transects from riparian plant communities reflect the communities' ability to modify the habitat. The decrease in nutrient concentration while passing through broad zones of either sedge communities or alderwóod and sedge communities may result from nutrient uptake by the components of those communities. The patterns in which sedge communities are forming floating mats, adjoined to the typical littoral or river bed, could be favourable for the protection of river and lake waters. The floating mats reacts elastically to wave action and changes in water level.     

Avian Community Responses to Variability in River Hydrology

River flow is a major driver of morphological structure and community dynamics in riverine-floodplain ecosystems. Flow influences in-stream communities through changes in water velocity, depth, temperature, turbidity and nutrient fluxes, and perturbations in the organisation of lower trophic levels are cascaded through the food web, resulting in shifts in food availability for consumer species. River birds are sensitive to spatial and phenological mismatches with aquatic prey following flow disturbances; however, the role of flow as a determinant of riparian ecological structure remains poorly known. This knowledge is crucial to help to predict if, and how, riparian communities will be influenced by climate-induced changes in river flow characterised by more extreme high (i.e. flood) and/or low (i.e. drought) flow events. Here, we combine national-scale datasets of river bird surveys and river flow archives to understand how hydrological disturbance has affected the distribution of riparian species at higher trophic levels. Data were analysed for 71 river locations using a Generalized Additive Model framework and a model averaging procedure. Species had complex but biologically interpretable associations with hydrological indices, with species’ responses consistent with their ecology, indicating that hydrological-disturbance has implications for higher trophic levels in riparian food webs. Our quantitative analysis of river flow-bird relationships demonstrates the potential vulnerability of riparian species to the impacts of changing flow variability and represents an important contribution in helping to understand how bird communities might respond to a climate change-induced increase in the intensity of floods and droughts. Moreover, the success in relating parameters of river flow variability to species’ distributions highlights the need to include river flow data in climate change impact models of species’ distributions.     

Hydrologic effects on riparian vegetation in a boreal river: an experiment testing climate change predictions

Climate change is expected to alter the magnitude and variation of flow in streams and rivers, hence providing new conditions for riverine communities. We evaluated plant ecological responses to climate change by transplanting turfs of riparian vegetation to new elevations in the riparian zone, thus simulating expected changes in water‐level variation, and monitored the results over 6 years. Turfs moved to higher elevations decreased in biomass and increased in species richness, whereas turfs transplanted to lower elevations gained biomass but lost species. Transplanted plant communities responded slowly to the new hydrologic conditions. After 6 years, biomass of transplanted turfs was statistically indistinguishable from target level controls, but species richness and species composition of transplants were intermediate between original and target levels. By using projections of future stream flow according to IPCC climate change scenarios, we predict likely changes to riparian vegetation in boreal rivers. Climate‐driven hydrologic changes are predicted to result in narrower riparian zones along the studied Vindel River in northern Sweden towards the end of the 21st century. Present riparian plant communities are projected to be replaced by terrestrial communities at high elevations as a result of lower‐magnitude spring floods, and by amphibious or aquatic communities at low elevations as a result of higher autumn and winter flows. Changes to riparian vegetation may be larger in other boreal climate regions: snow melt fed spring floods are predicted to disappear in southern parts of the boreal zone, which would result in considerable loss of riparian habitat. Our study emphasizes the importance of long‐term ecological field experiments given that plant communities often respond slowly and in a nonlinear fashion to external pressures.     

黄河干流河岸带植物群落特征及其影响因子分析

作为河岸带生态系统的关键组成部分,河岸带植被为许多动植物提供了栖息地以及迁徙或扩散的廊道,并对非点源污染物有着缓冲和过滤作用。黄河是我国湿地的重要组成部分,也是生物多样性分布的关键地带。但是,目前黄河水资源的过度利用如农业灌溉和干流拦河水利工程的兴建在很大程度上改变了原有的水文情势,对河岸带植被发育带来了不利影响。另外,黄河两岸的加固硬化进一步破坏了河岸带植物的生存环境。然而,过去对于黄河河岸带植被仅有对个别河段的调查。为了解目前黄河河岸带植被现状,于2008年4-6月及2008年9-10月对黄河干流河岸带植被进行了两次系统调查,以期为黄河河岸带植被多样性的保护、河岸带的开发管理提供理论支持。对群落的物种组成、多样性进行了分析,并采用双向指示种分析法对黄河干流河岸带植被进行了数量分类。共采集到木本和草本植物169种,隶属于37科124属。区系分析表明黄河干流河岸带植被区系地理成分多样。空间分布方面,中游河段草本植物无论在种类数、密度、生物量上都较上游和下游河段丰富。TWINSPAN将植被划分为17个群落,论述了各群落的特征。环境分析表明,影响黄河干流河岸带植被空间分布的主要生态因子是海拔、年均气温、年均降雨量、年均径流量和平均最大流速。