大堤型湖滨带生态系统健康状态驱动因子——以太湖为例

湖滨带是湖泊生态系统的重要组成部分,对维持湖泊生态系统健康和改善水环境功能具有积极作用。由于防洪需要,我国许多湖泊在湖滨带中修建了防洪大堤,防洪大堤对湖滨带生态系统的影响还缺乏研究,识别引起大堤型湖滨带生态健康退化的驱动因子是开展湖滨带生态修复的必要前提。针对太湖湖滨带的特点,在定性筛选了太湖主体营养状态、入湖河流污染负荷通量、岸带类型、风浪强度4个主要影响因子的基础上,分别采用"多元线性逐步回归法"和"偏相关系数法"进行驱动因子识别,2种方法确定的驱动因子个数均为3个,且3者的驱动力大小排序也相同,即太湖主体营养状态>岸带类型>入湖河流污染负荷通量。3个驱动因子对太湖湖滨带生态系统健康的影响均为负效应,也即太湖主体的营养状态综合指数越高、入湖河流污染负荷通量越重、岸带状况越差,湖滨带生态系统也就越不健康。另外,从统计方法的角度解释了"风浪强度"没有入选为驱动因子的原因;澄清了现阶段环境学、生态学领域对"驱动因子"识别方法的误解及不足之处。研究结果为大堤型湖滨带的生态修复方案提供了理论支持。     

小型城市湖泊生态系统预警技术--以武汉市汉阳地区为例

城市湖泊正面临着水体污染和生态系统退化的双重压力 ,对湖泊生态系统的状态进行预警是判定湖泊演化趋势以及制定相应控制对策的重要途径和手段。本文以武汉市汉阳地区的 6个小型城市湖泊为例 ,结合国内外的研究进展 ,从水生生态系统、湖滨生态系统和入湖沟渠生态系统 3方面入手 ,结合生物监测、生物标志物技术 ,综合考虑水文、水质和生态系统以及污染物扩散等因素 ,设计出汉阳地区湖泊生态系统的预警技术体系。该技术体系主要分 5步 :湖泊生态系统现状调研、生物标志物和关键指示因子确定、水质 -生态系统模拟、系统输出和灵敏度检验以及生态系统状态预警及对策、措施     

星云湖硅藻群落响应近现代人类活动与气候变化的过程

随着人类活动的增强与全球气候变暖的持续,近年来云南湖泊的生态系统功能持续退化,而目前对云南湖泊生态系统的研究还主要集中于单一环境压力的生态效应。以星云湖为研究对象,通过沉积物记录与现代监测资料,识别在湖泊富营养化、气候变化以及人类强烈干扰下硅藻群落结构响应的过程,并甄别驱动群落变化的主要环境压力及其强度。结果显示随着湖泊生产力水平(如沉积物叶绿素a浓度)的增加,硅藻物种组成发生了明显的变化,主成分分析表明了水体富营养化是驱动群落变化的主要环境因子(r=-0.63,P0.001)。简约模型与方差分解的结果表明近200年来(钻孔长度38cm),湖泊营养水平和水动力是驱动星云湖硅藻群落变化的主要环境因子,分别解释了群落变化的18.8%和2.9%;而1951年以后,湖泊营养水平和温度分别解释了硅藻群落结构变化的31.4%和26.8%。研究结果表明了硅藻群落长期变化的主控因子是湖泊营养水平,而人类活动及气候变化等可以通过改变湖泊水动力及湖水温度来驱动硅藻群落的演替,同时抚仙湖-星云湖的连通性也对硅藻群落的演替产生了一定影响。     

湖泊硫循环微生物研究进展

湖泊是响应气候和环境变化的关键生态系统,是研究元素(如碳、氮和硫等)生物地球化学循环的热点环境。湖泊(尤其咸盐湖)具有硫酸盐含量高且含硫化合物种类丰富的特点,因而湖泊中硫元素生物地球化学循环过程非常活跃。微生物是驱动湖泊硫循环的重要推手。因此,研究湖泊中微生物参与的硫元素生物地球化学循环过程以及相关微生物类群构成,对于深入探索微生物在湖泊生态系统中的作用具有重要意义。本文综述了湖泊中驱动硫循环的微生物(硫氧化菌和硫酸盐还原菌)种群多样性、功能基因、代谢途径、硫氧化/硫酸盐还原速率及其对环境条件变化响应等方面的研究现状,并对未来湖泊微生物驱动的硫循环研究方向进行了展望。     

淡水湖泊附着藻类生态学研究进展

附着藻类是淡水生态系统初级生产者的主要组成部分,对淡水生态系统营养盐循环及沉水植物分布具有重要的影响。本文对近年来淡水湖泊生态系统中附着藻类群落组成、生态功能以及主要影响因子进行了分析,从附着藻类种群结构入手,指出附着藻类通过改变群落中优势种的组成来适应不同的环境,阐述了附着藻类在湖泊生态系统营养盐循环中的作用及其与沉水植物之间的关系。针对淡水湖泊富营养化问题,提出了今后附着藻类生态学研究应侧重于:主要因子(如弱光、高浓度的营养盐等)的交互作用对附着藻类的影响,原位实验方法弄清楚附着藻类在湖泊生态系统碳、氮、磷生物地球化学循环中的作用,以及富营养湖泊附植藻类与沉水植物相互作用的机理。     

长江中下游四大淡水湖生态系统完整性评价

长江中下游地区是我国淡水湖泊集中分布区域,研究该区域湖泊生态系统完整性对于湖泊生态系统保护和恢复具有重要意义。物理、化学和生物完整性指标已经广泛应用于河湖生态系统健康评价,但是缺少物理、化学和生物完整性的综合评价方法。以历史调查状况为主要参照系统,构建了基于物理、化学和生物完整性的多参数湖泊完整性综合评价指标体系,结合近年来长江中下游四大淡水湖(洞庭湖、鄱阳湖、巢湖、太湖)生态系统调查数据,对四大淡水湖生态系统完整性进行了评价。结果表明,洞庭湖、鄱阳湖、巢湖和太湖的综合得分分别为66、71、57和57。根据评价等级划分标准,洞庭湖和鄱阳湖生态系统完整性状况都达到"好"的等级,而巢湖和太湖则处于"一般"等级;结果显示,该指标能够表征人类活动对于湖泊生态系统完整性不同方面的干扰,且能够反映四大淡水湖生态系统完整性历史变化状况。因此,该方法可以作为长江中下游淡水湖泊生态系统完整性综合评价的工具并能够为湖泊生态系统的保护和恢复提供科学支撑。     

青藏高原高寒草地生物多样性与生态系统功能的关系

生物多样性和生态系统功能(BEF)之间的关系是目前陆地生态系统生态学研究的热点, 对于生态系统的高效利用与管理意义重大, 而且对于退化生态系统功能的恢复及生物多样性的保护有重要的指导作用。高寒草地是青藏高原生态系统的主体, 近年来, 在气候变化与人为干扰等因素的驱动下, 高寒草地生态系统功能严重衰退。为此, 本文在综述物种多样性和生态系统功能及其相互关系研究进展的基础上, 首先从地下生态学过程研究、全球变化对生态系统多功能性的影响等方面解析了目前关于草地生物多样性和生态系统功能研究中存在的问题。继而, 从不同草地类型、草地退化程度、放牧、模拟气候变化、刈割、施肥、封育和补播等干扰利用方式对高寒草地物种多样性与生态系统功能的影响进行了全面的评述。并指出了高寒草地BEF研究中存在的不足, 今后应基于物种功能多样性开展高寒草地BEF研究, 全面且综合地考虑非生物因子(养分资源、外界干扰、环境波动等)对生物多样性与生态系统功能之间关系的影响, 关注尺度效应和要素耦合在全球气候变化对高寒草地BEF研究中的作用。最后, 以高寒草地BEF研究进展和结论为支撑依据, 综合提出了高寒草地资源利用和生物多样性保护的措施与建议: 加强放牧管理, 保护生物多样性; 治理退化草地, 维持生物多样性功能; 加强创新保护理念, 增强生态系统功能。     

人工湿地系统在湖泊生态修复中的作用

湖泊在维系区域水安全、生态安全和环境安全中具有重要价值。然而,受到人类非理性水土资源开发活动和全球变化的影响,部分湖泊遭到污染、无序垦殖及生态和环境需水被挤占而发生退化,其生态服务功能和经济社会价值也显著降低,对湖泊进行生态修复已成为政府部门、学术界和社会公众共同关心的资源与环境问题之一。在湖泊生态修复中,人工湿地系统可有效降低湖泊污染负荷,对湖泊生态系统的非生物环境进行有效调控;此外,人工湿地系统可对湖泊生物物种进行定向培育、增殖和保护。人工湿地系统消减湖泊污染负荷主要包括对外源性污染负荷的生态拦截和对内源性污染负荷的生态萃取。根据外源性污染负荷的入湖方式,生态拦截又包括针对无组织排放污染负荷(主要包括农田区坡面径流和城市地表径流)的带状拦截和针对有组织排放污染负荷的前置库拦截及线状拦截。在利用人工湿地系统进行湖泊生态修复过程中,需要结合湖泊生态系统的基本特征、生态退化的动力学机制和生态修复目标,按照节水、节地原则,适时、适地、适效地建设人工湿地系统及组合系统,充分发挥人工湿地系统对湖泊的综合生态修复功能。需要特别指出的是,在利用人工湿地系统进行湖泊生态修复过程中,要在多方论证和生态风险调控的基础上进行,避免外源性物种入侵对湖泊生态系统的破坏。     

湿地水文连通影响因素及生态效应研究进展

水文连通是湿地生态过程的主要非生物驱动因子之一, 对湿地生态保护起着重要作用。在高强度人类活动和自然条件变化双重作用下, 湿地水文连通性发生显著变化, 对湿地生物多样性及物质循环产生影响, 导致一系列生态环境问题。充分认识湿地水文连通的主要影响因素: 植物因子、气候变化、人类活动及其生态效应机制将有助于维持湿地生态系统的稳定性。针对影响因素提出相应调控措施, 对湿地修复起到积极作用。     

淡水水生生态系统温室气体排放的主要途径及影响因素研究进展

淡水水生生态系统是全球陆域生态系统的重要组成部分,近年来,关于淡水水生生态系统温室气体排放的研究日益增多。基于国内外目前对湖泊、河流、水库及浅水池塘等淡水生态系统开展的最新研究成果,总结分析了淡水水生生态系统温室气体排放的3个主要途径及相应观测方法。气泡排放的观测方法有倒置漏斗法、开放式动态箱法和超声探测技术;植物传输的观测方法有密闭箱法和植株切割法;扩散途径的观测方法有静态浮箱法、模型估算法/梯度法、微气象学法、TDLAS吸收光谱法等。从物理因素、化学因素、生物因素、水动力因素和人类活动等角度,深入探讨了淡水水生生态系统温室气体排放通量的影响因素。最后根据当前研究中存在的不足,对今后的研究方向提出了建议,以期为我国进一步深入开展相关研究提供借鉴。     

生态系统退化程度诊断：生态恢复的基础与前提

 生态系统退化程度诊断是进行生态恢复与重建的基础和前提。然而目前的生态系统化程度诊断大多停留在定性的水平,如何对退化生态系统的退化程度进行定量的诊断就成为恢复生态学与生态恢复实践所面临的一个迫切且十分关键的问题。在综述前人研究的基础上,比较系统地论述了生态系统退化程度诊断的一系列问题：绘制了描述生态系统退化程度的概念模型;认为在实践中退化程度诊断的参照系统可以选择相应的受人类或自然干扰程度比较轻的“自然生态系统”;归纳了生态系统退化程度诊断的生物途径、生境途径、生态过程途径、生态系统功能/服务途径、景观途径;把诊断方法分为单途径单因子诊断法、单途径多因子诊断法、多途径综合诊断法;分析了生态系统退化程度诊断的可能指标（体系）;给出了生态系统退化程度诊断的策略与流程,并对生态系统退化程度诊断及生态恢复过程中应注意的事项进行了讨论。建议我国加强典型生态系统退化程度的综合诊断研究。     

国内外主要湾区生态系统特征、修复理论与技术模式

通过总结粤港澳大湾区、东京湾区和旧金山湾区等国内外主要湾区的生态系统特征、生态修复理论和实践研究进展,在辨析生态修复概念内涵的基础上,基于Meta-Analysis及综合分析方法,分析了生态系统退化机制及驱动因子,归纳总结湾区生态修复的主要理论基础、技术模式及案例。结果表明：（1）国内外三大主要湾区的生态系统特征为森林占比最高,其次是农田和草地占比,城镇占比第三。森林一般分布在湾区外围,城镇分布在湾区内核河口三角洲附近。（2）湾区生态修复理论包括以恢复生态学、景观生态学和复合生态系统生态学为基础的三种修复理论,生态修复的类别分为补救修复、改善修复、生态恢复和复垦等。（3）湾区生态修复技术模式包括主动修复、被动修复和重建等三类技术模式。在总结梳理生态修复理论和技术模式的基础上,结合当前国内生态修复存在问题,本文提出我国和广东省开展生态修复实践的建议和展望,以期为粤港澳大湾区生态修复提供一定的理论指导。     

A functional trait perspective on plant invasion

Background and Aims

Global environmental change will affect non-native plant invasions, with profound potential impacts on native plant populations, communities and ecosystems. In this context, we review plant functional traits, particularly those that drive invader abundance (invasiveness) and impacts, as well as the integration of these traits across multiple ecological scales, and as a basis for restoration and management.

Scope

We review the concepts and terminology surrounding functional traits and how functional traits influence processes at the individual level. We explore how phenotypic plasticity may lead to rapid evolution of novel traits facilitating invasiveness in changing environments and then ‘scale up’ to evaluate the relative importance of demographic traits and their links to invasion rates. We then suggest a functional trait framework for assessing per capita effects and, ultimately, impacts of invasive plants on plant communities and ecosystems. Lastly, we focus on the role of functional trait-based approaches in invasive species management and restoration in the context of rapid, global environmental change.

Conclusions

To understand how the abundance and impacts of invasive plants will respond to rapid environmental changes it is essential to link trait-based responses of invaders to changes in community and ecosystem properties. To do so requires a comprehensive effort that considers dynamic environmental controls and a targeted approach to understand key functional traits driving both invader abundance and impacts. If we are to predict future invasions, manage those at hand and use restoration technology to mitigate invasive species impacts, future research must focus on functional traits that promote invasiveness and invader impacts under changing conditions, and integrate major factors driving invasions from individual to ecosystem levels.     

三江源区退化高寒生态系统恢复技术与示范

"三江源区退化高寒生态系统恢复技术与示范"(2016YFC0501900)是国家重点研发计划"典型脆弱生态修复与保护研究"专项中"青藏高原生态系统功能提升与适应性管理"指南方向下的第二个项目。项目以综合生态系统管理方法为支撑点,以三江源区退化严重的三类主体生态系统——高寒草甸、高寒草原和高寒湿地为研究对象,以"土壤(土)-植被(草)-动物(畜)"协同恢复的思路为指导,通过创新性、系统性、综合性的科学研究,自主研发三江源区生态恢复与生态衍生产业发展的综合技术体系,完善生态恢复及产业发展模式评估和监测技术体系,推动生态恢复和区域发展模式的转型升级,提升生态整体恢复的技术水平和监管能力,解决三江源退化草地恢复重建及功能提升的重大问题,旨在为三江源的生态建设提供科技支撑和系统解决方案。     

关于中国淡水生态系统生物多样性监测与管理的探讨

China is one of the countries in the world with therichest species biodiversityinfreshwater ecosystem.How-ever,duetothe rapid economic growthandthe continuingincrease of human disturbances and destructions of aquatichabitats,the biodiversity of freshwater ecosystemsis dras-tically declining.Waterbodies become more and more“deserted”of sensitive species.Water areas are reduced,fragmentized,and changed in their hydrodynamics(i.e.damming),causing changes in sedimentation and otherchanges.Forinstance,the area o...     

Identifying Linkages among Conceptual Models of Ecosystem Degradation and Restoration: Towards an Integrative Framework

We present an ecological framework for considering ecosystem degradation and restoration, particularly in rangelands and arid environments. The framework is a synthesis of three conceptual models previously developed by several rangeland and restoration ecologists. We focus first on distinctions and connections between structural and functional components of rangeland ecosystems and then on distinctions and connections between biotic and abiotic components of the ecosystem. We next show that the structural/functional and biotic/abiotic distinctions can be integrated with a stepwise, positive feedback model of degradation to help explain degradation processes and restoration approaches. Finally, we relate those concepts to a threshold model of rangeland degradation. By establishing the conceptual links among these different models, this synthesis provides a broader, more integrated framework for thinking about the dynamics involved in rangeland degradation and restoration. We conclude by presenting some approaches to restoration that are motivated by the suite of concepts that are brought together in the framework.     

Restoration and Rehabilitation of Degraded Ecosystems in Arid and Semi-Arid Lands. I. A View from the South

A general model is presented describing ecosystem degradation to help decide when restoration, rehabilitation, or reallocation should be the preferred response. The latter two pathways are suggested when one or more “thresholds of irreversibility” have been crossed in the course of ecosystem degradation, and when “passive” restoration to a presumed predisturbance condition is deemed impossible. The young but burgeoning field of ecological restoration, and the older field of rehabilitation and sustainable range management of arid and semiarid lands (ASAL), are found to have much in common, especially compared with the reallocation of lands, which is often carried out without reference to pre-existing ecosystems. After clarifying some basic terminology, we present 18 vital ecosystem attributes for evaluating stages of degradation and planning experiments in the restoration or rehabilitation of degraded ecosystems. Finally, we offer 10 hypotheses concerning ecological restoration and rehabilitation as they apply to ASAL and perhaps to all terrestrial ecosystems.     

Environmental Technologies of Woody Crop Production Systems

Soil erosion, loss of productivity potential, biodiversity loss, water shortage, and soil and water pollution are ongoing processes that decrease or degrade provisioning (e.g., biomass, freshwater) and regulating (e.g., carbon sequestration, soil quality) ecosystem services. Therefore, developing environmental technologies that maximize these services is essential for the continued support of rural and urban populations. Genotype selection is a key component of these technologies, and characteristics of the species used in short rotation woody biomass systems, as well as the silvicultural techniques developed for short rotation woody crops are readily adapted to environmental applications. Here, we describe the development of such woody crop production systems for the advancement of environmental technologies including phytoremediation, urban afforestation, forest restoration, and mine reclamation. The primary goal of these collective efforts is to develop systems and tools that can help to mitigate ecological degradation and thereby sustain healthy ecosystems across the rural to urban continuum.     

A conceptual framework for urban ecological restoration and rehabilitation

Urban greenspace has gained considerable attention during the last decades because of its relevance to wildlife conservation, human welfare, and climate change adaptation. Biodiversity loss and ecosystem degradation worldwide require the formation of new concepts of ecological restoration and rehabilitation aimed at improving ecosystem functions, services, and biodiversity conservation in cities. Although relict sites of natural and semi-natural ecosystems can be found in urban areas, environmental conditions and species composition of most urban ecosystems are highly modified, inducing the development of novel and hybrid ecosystems. A consequence of this ecological novelty is the lack of (semi-) natural reference systems available for defining restoration targets and assessing restoration success in urban areas. This hampers the implementation of ecological restoration in cities. In consideration of these challenges, we present a new conceptual framework that provides guidance and support for urban ecological restoration and rehabilitation by formulating restoration targets for different levels of ecological novelty (i.e., historic, hybrid, and novel ecosystems). To facilitate the restoration and rehabilitation of novel urban ecosystems, we recommend using established species-rich and well-functioning urban ecosystems as reference. Such urban reference systems are likely to be present in many cities. Highlighting their value in comparison to degraded ecosystems can stimulate and guide restoration initiatives. As urban restoration approaches must consider local history and site conditions, as well as citizens’ needs, it may also be advisable to focus the restoration of strongly altered urban ecosystems on selected ecosystem functions, services and/or biodiversity values. Ecosystem restoration and rehabilitation in cities can be either relatively inexpensive or costly, but even expensive measures can pay off when they effectively improve ecosystem services such as climate change mitigation or recreation. Successful re‐shaping and re-thinking of urban greenspace by involving citizens and other stakeholders will help to make our cities more sustainable in the future.     

祁连山山水林田湖草生态保护与修复的探索与实践

遵循“山水林田湖草是一个生命共同体”的先进理念,实施生态系统的整体保护、系统修复、综合治理,是加强生态文明建设的新举措。现阶段生态保护与修复的研究主要集中在内涵、机制及启示等方面,为“山水林田湖草”生态保护修复提供了理论与技术支撑,但缺乏系统性的梳理与总结。以中国重要生态功能区祁连山为例,以生态地位、退化现象及成因为切入点,结合已开展的生态保护修复工程,总结了典型生态保护修复措施,提出了有针对性的策略与建议,旨在为山水林田湖草生态修复提供模式示范。祁连山生态退化的原因主要为：全球气候变暖、人类活动干预、传统发展理念制约及环境保护投入不足等。典型生态保护与修复措施已涵盖了“山水林田湖草”各个方面,但在工程实践中如何有机整合各项措施,使生态系统成为“生命共同体”仍是未来探索的科学问题。生态保护修复的理论与实践还需完善以下内容：加强基础调研与科技创新;加强统一规划与协同管理;积极完善生态补偿机制;建立由“开刀治病”工程治理向“健康管理”自然恢复逐步引导的生态修复理念。