退化生态系统恢复与恢复生态学

恢复生态学起源于100a前的山地、草原、森林和野生生物等自然资源的管理研究,形成于20世纪80年代。它是研究生态整合性的恢复和管理过程的科学。恢复生态学的研究对象是在自然或人为干扰下形成的偏离自然状态的退化生态系统。生态恢复的目标包括恢复退化生态系统的结构、功能、动态和服务功能,其长期目标是通过恢复与保护相结合,实现生态系统的可持续发展。恢复生态学的理论与方法较多,它们均源于生态学等相关学科,但自我设计和人为设计是唯一源于恢复生态学研究和实践的理论。由于生态系统的复杂性,退化生态系统恢复的方向和时间具有不确定性,其恢复的机理可用临界阈值理论和状态跃迁模型进行解释。中国森林恢复中存在的问题包括：大量营造种类和结构单一的人工林忽视了生物多样性在生态恢复中的作用;大量使用外来种;忽视了生态系统健康所要求的异质性;忽略了物种间的生态交互作用;造林时对珍稀濒危种需要缺乏考虑;城镇绿化忽略了植被的生态功能等问题。此外,还介绍了生态恢复的方法、成功恢复的标准,并提出了恢复生态学的发展趋势：恢复生态学尚未形成理论和方法体系,要成熟还有很长的路要走;恢复生态学正在强调自然恢复与社会、人文的耦合;对森林恢复研究要集中在恢复中的障碍和如何克服这些障碍两个方面;鉴于生态系统复杂性和动态性,应停止期待发现能预测恢复产出的简单定律,相反,应该根据恢复地点及目标多样性而强调适应性恢复。     

恢复生态学研究的一些基本问题探讨

对恢复生态学的研究概况、基本概念、内涵与研究内容以及生态恢复的目标、原则、程序与技术进行了分析与探讨。指出恢复生态学应加强基础理论研究(包括生态系统的演替理论及干扰条件下生态系统的受损过程与响应机制研究等)和应用技术研究(包括土壤、水体、大气和植被恢复技术、生物多样性保护技术以及生态系统的组装与集成技术等).生态恢复与重建是指根据生态学原理,通过一定的生物、生态以及工程的技术,人为地切断生态系统退化的主导因子和过程,调整和优化系统内部及其与外界的物质、能量和信息的流动过程及其时空秩序,使生态系统的结构、功能和生态学潜力尽快地成功地恢复到原有的乃至更高的水平。     

种、种的多样性及退化生态系统功能的恢复和维持研究

物种多样性是生态系统的重要特征并维持系统的功能支行,生物种和不同种类构成的群落为人类提供诸如营养物质循环、生物生产力、营养功能等形式的重要生态服务,特种多样性与生态系统抵御逆境和干扰的能力紧密相关,多样性的提高会增加系统的稳定性,与单个种和种类的数量相比,功能群和功能多样性对生态系统功能的影响效应要大得多,且易于被用来测度稳定性和预测群落变化,本文提出并探讨了种对生态系统功能作用的几种形式,理解物种多样性与生态系统的功能关系能指导退化生态系统恢复和维持其功能的实践活动,尤其为恢复的初始阶段进行群落的“种类组装”提供生态理论基础。     

河岸带生态系统退化机制及其恢复研究进展

恢复和重建自然和人为干扰导致的退化河岸带生态系统是目前恢复生态学、流域生态学等学科研究的重要内容之一．对河岸带生态系统的干扰表现在河流水文特征改变、河岸带直接干扰和流域尺度干扰3个方面,分别具有不同的影响机制．河流水文特征改变通过改变河岸土壤湿度、氧化还原电位、生物生存环境以及沉积物传输规律对河岸带生态系统产生影响;河岸带直接干扰通过人类活动及外来物种入侵而直接影响河岸带植被多样性;流域尺度干扰则主要表现在河道刷深、河道淤积、河岸带地下水位降低和河流冲刷过程改变等．河岸带生态恢复评价对象包括河岸带生态系统各要素,评价指标已从单一的生态指标转向综合性指标．河岸带生态恢复应在景观或者流域尺度上进行考虑,识别对其影响的生物和物理过程以及导致其退化的干扰因子,通过植被重建与水文调控来进行．扩展研究尺度和研究对象及采用多学科的研究方法将是今后相关研究中的重要问题．     

关于生态重建和生态恢复的思辨及其科学涵义与发展途径

Ecological restoration是现代生态学最活跃的关键行动之一, 在我国被译为“生态恢复”。经查验其英语涵义和演变过程, 建议正名为“生态重建”, 指在人为辅助下的生态活动。而“生态恢复”(recovery)在国际文献中指没有人直接干预的自然发生过程, 二者不容混淆。作者强调自然恢复和生态重建的三类时间尺度, 即地质年代尺度(千、万、亿年)自然生态系统世代交替和演替尺度(十、百、千年)和生态建设时间尺度(一、十、百年)。前二者为自然恢复尺度。三者相差2-3个数量级或更多。人类不能超尺度地依赖自然恢复能力, 自然与人为时间尺度的不匹配是自然恢复难以满足人类社会生态需求的根本原因。作者质疑“以自然恢复为主”和“从人工建设转向自然恢复为主的转变”提法。认为把生态重建的责任推诿给自然去旷日持久地恢复, 是不负责任和不作为的逻辑和有悖于“谁破坏, 谁补偿; 谁污染, 谁治理; 谁享用, 谁埋单”的全球环保公理和生态伦理观念。除恢复重建自然的生态系统外, 还要发展人工设计生态方案等未来生态重建途径。     

动植物在陆地退化生态系统恢复中的作用及其研究进展

生态系统退化导致了生物生境丧失、多样性下降和生产力降低, 所以, 恢复退化的生态系统, 已成为亟待解决的重要课题, 关系到人类社会的可持续发展。因此, 阐述了生态系统退化的现状, 并分析了其退化的人为和自然原因; 比较分析了植物恢复、动物恢复及动植物联合恢复等生态恢复方法的适用性、有效性、局限性及恢复机制, 得出以下结论: 动、植物恢复首先应通过生态势和基础生态位等的分析, 筛选出较为适宜的本土生物, 这些生物的引入主要是通过收集种源、改善生境和构建生物廊道等途径进行; 引进外来物种进行生态恢复, 须评估外来种的入侵风险、适应性和生态功能; 同时注意利用植物和植物、植物与动物间的生态位、化感作用和互惠共生等互作关系, 并结合生态记忆的方法, 进行动植物的合理组合, 形成系统的生态恢复技术, 进而实现退化生态系统的全面恢复。     

热带森林植被生态恢复研究进展

热带森林是地球上生物多样性最高和生态功能最为强大的植被类型之一,在维护全球生态平衡中起着至关重要的作用,同时也为人类社会提供着多种多样的物质资源和生态系统服务。然而热带森林是目前生物多样性消失最快和生态功能退化最为严重的生态系统之一,如何有效地保护现存的热带森林不再进一步退化,以及如何使已经退化的生态系统尽快得到恢复是生态学工作者面临的重要议题。不同方式、规模和强度的干扰对热带林的破坏程度及其以后的恢复过程产生的影响不同。除少数大型自然干扰事件外,采伐、刀耕火种、农业开发用地等人为干扰是造成当前热带森林植被大面积退化的主要原因。多种干扰交互作用、杂草与外来物种入侵、退化植被和土壤状况、残存植被组分及土壤种子库、退化植被周围的景观格局以及全球气候变化等因素都能够影响热带森林植被恢复的速度和方向。基于功能群的研究思想将可能为物种丰富的热带森林植被恢复的研究提供一个全新途径。     

废黄河三角洲生态修复设想

生态系统退化导致生态系统为人类生存和发展提供的物品和服务功能下降,从而阻碍区域经济和社会发展。本文以废黄河三角洲为例,分析了废黄河三角洲生态系统退化的自然和人为应力以及生态系统的退化过程。针对废黄河三角洲生态现状,提出了生态修复的目标及措施,采取自然恢复和人工干预的手段,加强水生生态系统修复和生物多样性的提高,实现区域经济与生态协调发展。     

生物多样性与生态系统服务——关系、权衡与管理

生物多样性和生态系统服务是人类生存和社会经济可持续发展的物质基础,应对生物多样性丧失和生态系统服务退化问题已经成为继气候变化之后的又一个全球性环境热点问题。生物多样性是生态系统生产力、稳定性、抵抗生物入侵以及养分动态的主要决定因素,生物多样性越高,生态系统功能性状的范围越广,生态系统服务质量就越高越稳定。目的是探讨生物多样性和生态系统服务之间的关系:(1)明确了生物多样性与生态系统过程、功能、服务之间的关系;(2)生物多样性在生态系统服务中的角色:生物多样性在不同的空间尺度通过各种形式的运行机制与生态系统服务产生联系,生物多样性是生态系统过程的调节者,是巩固生态系统服务的一个重要因素,生物多样性也是一种终极的生态系统服务,并在遗传和物种水平上直接贡献了其利益和价值;(3)生物多样性与生态系统服务权衡和协同关系的研究可以更好的帮助管理人员做出有利的决策和保护工作,也是制定规划和适应策略以减少生物多样性危机带来的不利影响的基础;(4)生物多样性与生态系统服务的关系在不同的时间和空间尺度上是不恒定的,有必要共同确定生态系统服务和生物多样性的空间格局,以有效和可持续的进行生态系统管理;(5)虽然生物多样性保护和生态系统管理还存在许多不确定性,但相关理论应该在管理、保护和恢复生态系统中发挥重要作用。研究提出了进一步研究的领域,以促进生物多样性保护和生态系统服务提供之间的协同作用。希望对相关领域的研究有所帮助。     

海草床生态系统的退化及其恢复

海草床是生产力和生物多样性最高的典型海洋生态系统之一,目前全球海草床呈现退化趋势,自然干扰和人类活动的负面影响是其退化原因,以后者为主.海草退化的生理生态机制主要是光合作用速率、光合色素荧光强度和含量、酶活性等生理生态指标在胁迫(高温、光照、盐度、污染物等)下发生显著变化.海草床监测和保护计划已经在局部区域取得成效,使部分海草床得到恢复.中国的海草床恢复研究重点应放在生物多样性保护、海草移植和海草床生态系统服务价值评估.     

Restoration Enhances Wetland Biodiversity and Ecosystem Service Supply,but Results Are Context-Dependent: A Meta-Analysis

Wetlands are valuable ecosystems because they harbor a huge biodiversity and provide key services to societies. When natural or human factors degrade wetlands, ecological restoration is often carried out to recover biodiversity and ecosystem services (ES). Although such restorations are routinely performed, we lack systematic, evidence-based assessments of their effectiveness on the recovery of biodiversity and ES. Here we performed a meta-analysis of 70 experimental studies in order to assess the effectiveness of ecological restoration and identify what factors affect it. We compared selected ecosystem performance variables between degraded and restored wetlands and between restored and natural wetlands using response ratios and random-effects categorical modeling. We assessed how context factors such as ecosystem type, main agent of degradation, restoration action, experimental design, and restoration age influenced post-restoration biodiversity and ES. Biodiversity showed excellent recovery, though the precise recovery depended strongly on the type of organisms involved. Restored wetlands showed 36% higher levels of provisioning, regulating and supporting ES than did degraded wetlands. In fact, wetlands showed levels of provisioning and cultural ES similar to those of natural wetlands; however, their levels of supporting and regulating ES were, respectively, 16% and 22% lower than in natural wetlands. Recovery of biodiversity and of ES were positively correlated, indicating a win-win restoration outcome. The extent to which restoration increased biodiversity and ES in degraded wetlands depended primarily on the main agent of degradation, restoration actions, experimental design, and ecosystem type. In contrast, the choice of specific restoration actions alone explained most differences between restored and natural wetlands. These results highlight the importance of comprehensive, multi-factorial assessment to determine the ecological status of degraded, restored and natural wetlands and thereby evaluate the effectiveness of ecological restorations. Future research on wetland restoration should also seek to identify which restoration actions work best for specific habitats.     

Land management implications for ecosystem services in a South African rangeland

In South Africa, restoration and sustainable management of historically overgrazed and degraded rangelands are promoted to increase biodiversity and ecosystem service provision. This study evaluates different land management scenarios in terms of ecosystem services in a South African rangeland, the Baviaanskloof catchment. As measured data were limited, we used simple models to quantify and map the effect of the different combination of agricultural, nature conservation and restoration practices on multiple ecosystem services. The land management scenarios were evaluated against management targets set for individual ecosystem services. Results highlight how the provision of ecosystem services is related to land management as unmanaged, pristine ecosystems provide a different mix of ecosystem services than ecosystems recently restored or managed as grazing lands. Results also indicate that historically overgrazed lands provide no forage, may retain 40% less sediment and have 38% lower biodiversity, while providing 60% more fuel wood and supplying two and half times more water (i.e. retaining less water), than pristine or restored lands. We conclude that a combination of light grazing, low input agriculture, nature conservation and restoration is the best for the sufficient provision of multiple ecosystem services. Applying such mixed management would improve biodiversity, ecotourism and maintain forage production and regulating services on farmers’ land. This management option also fits into and further optimizes local decision-makers’ vision regarding the future management of the area.     

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.     

Restoration of Biodiversity and Ecosystem Services on Agricultural Land

Cultivation and cropping are major causes of destruction and degradation of natural ecosystems throughout the world. We face the challenge of maintaining provisioning services while conserving or enhancing other ecosystem services and biodiversity in agricultural landscapes. There is a range of possibilities within two types of intervention, namely “land sharing” and “land separation”; the former advocates the enhancement of the farmed environment, but the latter a separation between land designated for farming versus conservation. Land sharing may involve biodiversity-based agricultural practices, learning from traditional farming, changing from conventional to organic agriculture and from “simple” crops and pastures to agro-forestry systems, and restoring or creating specific elements to benefit wildlife and particular services without decreasing agricultural production. Land separation in the farmland context involves restoring or creating non-farmland habitat at the expense of field-level agricultural production—for example, woodland on arable land. Restoration by land sharing has the potential to enhance agricultural production, other ecosystem services and biodiversity at both the field and landscape scale; however, restoration by land separation would provide these benefits only at the landscape scale. Although recent debate has contrasted these approaches, we suggest they should be used in combination to maximize benefits. Furthermore, we suggest “woodland islets”, an intermediate approach between land abandonment and farmland afforestation, for ecological restoration in extensive agricultural landscapes. This approach allows reconciliation of farmland production, conservation of values linked to cultural landscapes, enhancement of biodiversity, and provision of a range of ecosystem services. Beyond academic research, restoration projects within agricultural landscapes are essential if we want to halt environmental degradation and biodiversity loss.     

生物多样性与生态系统服务关系研究进展

生物多样性与生态系统服务关系是当前生态学研究的热点之一,2005年千年生态系统评估之后如何将两者关系应用到生态系统管理和政策制定中逐渐受到重视。然而,从理论上的两者关系认知到应用上的管理实践仍面临着严峻挑战,梳理已有研究成果有利于更好地指导管理实践。本文基于近年生物多样性与生态系统服务关系的主要研究成果,从生物多样性对生态系统单种服务、多种服务、生态系统服务权衡的影响以及环境变化如何影响这些关系等方面,总结了两者关系的主要研究进展,概述了两者关系在自然保护区管理、森林生态系统管理、退化生态系统恢复和农业生态系统改善等领域中的应用,分析了两者关系研究中依然存在的不足之处,强调未来需加强的研究方向主要包括: 生物多样性不同组分相互作用和多营养级生物多样性相互关系对生态系统服务的影响、环境耦合变化对两者关系的复合效应以及生物多样性改善生态系统服务的实践途径。     

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。     

Myth‐busting tropical grassy biome restoration

The historical focus in research and policy on forest restoration and temperate ecosystems has created misunderstandings for the restoration of tropical and subtropical old‐growth grassy biomes (TGB). Such misconceptions have detrimental consequences for biodiversity, ecosystem services, and human livelihoods in woodlands, savannas, and grasslands worldwide. Here, we demystify TGB restoration myths to promote a positive agenda to increase the likelihood of success of ambitious landscape‐scale restoration goals of nonforest ecosystems. The 10 TGB restoration myths are: (1) grasslands originate from degraded forests, (2) tree cover is a reliable indicator of habitat quality, (3) planting trees is always good for biodiversity and ecosystem services, (4) grasslands are biodiversity‐poor and provide few ecosystem services, (5) enhancing plant nutrition is needed in restoration, (6) disturbance is detrimental, (7) techniques used to restore temperate grasslands also work for TGB, (8) grasslands represent early stages of forest succession, (9) grassland restoration is only about grasses, and (10) grassland restoration is fast. By demystifying TGB restoration, we hope that policymakers, scientists, and restorationists come to understand and embrace the value of these ecosystems and are motivated to establish policies, standards, indicators, and techniques that enhance the success of TGB restoration. We must abandon misperceptions and misunderstandings of TGB ecology that result in ill‐conceived policies and build an informed and compelling global ecosystem restoration agenda that maintains and improves the well‐being of all inhabitants of grassy biomes.     

Enhancing biodiversity and ecosystem services in quarry restoration – challenges,strategies, and practice

Although covering less than 1% of the land surface, extraction activities have long‐lasting impacts on local ecosystems, inevitably damaging biological diversity and depleting ecosystem services. Many extractive companies are now aware of their impacts and, while pressured by society, demand concrete solutions from researchers to reverse the effects of exploitation and restore biodiversity and ecosystems services. In this article, we compile and synthesize the contributions of the latest available research on quarry restoration. We depict and discuss some of the most pressing issues regarding (1) the challenges of restoring quarries; (2) the opportunities for biodiversity and ecosystem services delivery; and (3) outline further research addressing current gaps. We conclude that quarries pose different abiotic and biotic constraints that act interdependently, hampering the attainment of effective restoration if considered solely. Such constraints need to be addressed holistically to lastly encourage the self‐sustainability of the system by reinstating ecological processes. However, a restored site does not have to specifically mimic the pristine situation, as under certain conditions alternative approaches may uphold valuable natural assets contributing to the conservation of rare, restricted, or protected species and habitats.     

The potential of paleoecology for functional forest restoration planning: lessons from Late Holocene Italian pollen records

We describe forest landscape transformations during the last two millennia in the Italian peninsula by analyzing local (Rieti basin – Lago Lungo) and regional (RF93-30 Adriatic Sea) sediment cores. We identify a dynamic forest ecosystem through paleoecologic reconstruction and consider potential interventions for effective restoration of the most ancient, least disturbed forest ecosystem. The most degraded ecosystems in consequence of human activities were hygrophilous (wet) and mesic forests. In the Rieti Basin, degraded forest ecosystems on mountain slopes are undergoing some degree of forest succession and have less need of restoration. However, management plans for biodiversity, ecosystem services and resources conservation are needed to achieve more sustainable development. In Rieti, the paleoecological investigation revealed a dramatic decrease of deciduous wet and mesic tree taxa through time due to human landscape transformation. The starting point for restoration of a Mediterranean forest ecosystem that preserves natural biodiversity and associated ecosystem services requires recreating some portion of the floodplain wetland ecological niche. Once floodplain forest ecological niche has been recreated, the original ecosystem composed of Alnus, Fraxinus excelsior, Tilia spp., Carpinus betulus and Acer spp., all species which today are rare, should be planted on the basis of microsite characteristics and tree autoecology.     

Intermediate disturbance promotes diversity and the conservation of dung beetles (Scarabaeoidea: Scarabaeidae and Aphodiidae) in the Eastern Cape,South Africa

Environmental fluctuations, such as changes in climate, agricultural management and anthropogenic land-use patterns can affect the diversity of organisms inhabiting an area. Losses of biodiversity alter ecosystems processes, eroding their capacity to deliver ecosystem services. Dung beetles are critical ecosystem service providers, making them an ideal ecological indicator to explore the effects of land-use change on biodiversity. Dung beetles were sampled across three land-use types, in the summers of 2015 and 2016 in the Eastern Cape province, South Africa. Game ranching is regarded as a relatively low-intensity land use type. It was compared with cattle ranching (medium intensity) and dairy farming (high intensity) to examine their effect on dung beetle assemblage metrics (abundance, species richness and true Shannon diversity index), guild diversity (as nesting guilds) and spatial turnover. The intermediate grazing intensity of cattle ranching supported a higher abundance and diversity of both whole dung beetle assemblage and the nesting guilds, followed by the game ranches and then dairy farms. Differences between the sampling years were dependent on the beetle nesting guild, and largely correlated with rainfall and temperature. Cattle and game ranches shared a higher number of species than either shared with dairy farms. Whittaker's Beta-diversity index showed the highest species turnover between game ranches and dairy farms. A mix of game and cattle ranching, minimising dairy farming or restricting it to already ecological degraded sites, appears the best alternative for maintenance of dung beetle diversity and their ecosystem services. The year-to-year trends of the data were in general consistent, confirming that dung beetles are reliable ecological indicators; but also suggest that climate change that affects rainfall will result in the reduction of the abundance and diversity of this key ecological group.