景感生态学在流域生态系统保护与修复实践中的应用——以大凌河流域北票段为例

生态系统保护与修复已成为我国生态文明建设的一项核心内容，自2016年以来，在全国24个省（自治区、直辖市）已开展了25个山水林田湖草生态保护修复工程试点工程。以大凌河流域北票段为研究区，探讨了景感生态学理论在山水林田湖草生态系统保护与修复实践中的应用。基于景感生态学理论，构建大凌河流域北票段生态系统保护与修复综合治理框架，以保持、改善和提升生态系统服务，实现可持续发展为目标，构建了"一中心、二重点、五要素、六工程"的生态系统保护与修复景感空间体系，并基于此将大凌河流域北票段生态系统保护与修复分为5个重要治理区域，形成"一带四区"的生态安全格局，提出了应用景感生态学理论，构建区域居民的共同行为规范，引导并实现人类对自然生态系统的有利影响，进一步提升生态系统保护与修复效果的对策建议。通过大凌河流域北票段的分析案例，以景感营造的理念开展区域生态系统保护与修复顶层设计，为促进区域可持续发展提供思路和途径。     

新型生态系统理论及其争议综述

澳大利亚Richard J Hobbs教授等近年提出的新型生态系统(Novel Ecosystems)理论认为,由于人类作用,地球生态系统经历了前所未有的变化,很多生态系统已经越过不可逆转的阈值,不可能恢复到原有状态,形成了新的生态系统,其生物要素、非生物要素和系统功能等都发生了显著改变;人类应该面对现实,必须反思传统生态保护和生态恢复的行为、政策和思维;应该致力新型生态系统的特征、属性和演替规律的研究,在管理、规划、政策、组织和技术等方面的创新。新型生态系统理论引起了很大争议。质疑者认为,由于自然作用力和人类的持续扰动,地球生态系统一直在不断变化,所以一直都是"新"的,根本没必要贴上"新型"标签;该理论基本概念模糊,理论模型不精确,缺乏严密的逻辑推理,还很不成熟;该理论无助于生态保护和生态恢复的实践,会扰乱人们的思想,没有实践价值。不过,支持者和质疑者都承认地球上很多生态系统的确遭到严重破坏,已经发生深刻演替,极有必要对这类系统的非线性机制、系统阈值、恢复力、新范式,以及破坏后的所有特征等开展研究,应该理性选择合适的修复方法,理性分析人工干预的程度及其成功的可能性,科学制定行动方案和优选标准。跟踪国际前沿,开展新型生态系统理论研究有助于丰富我国恢复生态学理论以及创新工程实践。     

典型红壤区自然生态修复的适用性

自然修复主要通过封山育林、禁止农作、禁牧禁伐措施,减少人类对环境的扰动,利用自然生态环境的自我演替能力,恢复生态环境,实现生态平衡。自然修复作为一种成本低、无污染的生态修复手段很早就受到人们重视,但关于自然修复适用范围的研究较少。为了正确认识自然修复的适用性,选择了我国南方红壤地区长期遭受严重土壤侵蚀危害的福建省长汀县为研究对象,通过对长期自然修复样地的监测资料分析,发现在坡度条件为20%—30%下,当植被覆盖度低于20%的退化阈值时,严重的土壤侵蚀引发的土壤肥力损失将导致生态系统自我退化,自然修复不仅无法改善当地的生态系统,反而会引起生态系统的进一步恶化。由此可见,自然修复并不适合所有的生态系统,当生态系统退化到一定程度时,退化生态系统必须通过人工干预来修复。因此,必须探索适合当地的生态修复模式,在生态系统退化突破阈值时,红壤丘陵区应通过恢复土壤肥力、促进自然植被覆盖度增加、综合提高生态系统健康水平。     

山水林田湖草生态保护修复的理论支撑体系研究

山水林田湖草生态保护修复关系到我国生态文明建设和美丽中国建设进程,关系到国家生态安全和中华民族永续发展。开展山水林田湖草生态保护修复是生态文明建设的重要内容,是贯彻绿色发展理念的有力举措,也是破解当前生态环境与经济发展之间难题的必然要求。通过总结梳理当前我国山水林田湖草生态保护修复工作的进展与概况,立足于“山水林田湖草是生命共同体”的理论核心,详细阐释了山水林田湖草生态保护修复的内涵及理论体系。山水林田湖草生命共同体的基础理论是以生态系统生态学为支撑,基于流域生态学、恢复生态学和景观生态学的理论诠释山水林田湖草生命共同体的时空区域尺度及流域内部各生态系统之间的耦合机制,通过复合生态系统理论构建山水林田湖草生命共同体的社会、经济、自然生态系统的“架构”体系,明确了流域可持续发展是山水林田湖草生命共同体的最终发展目标。在构建山水林田湖草生态保护修复理论支撑体系的基础上,进一步总结凝练了山水林田湖草生态保护修复的技术体系,包括生态保护、修复与恢复技术、生态建设技术、生态功能提升技术、生态服务优化技术与监督管理技术等,为我国山水林田湖草生态保护修复工作提供坚实的理论和技术支撑体系。     

Turquoise is the new green: Restoring and enhancing riparian function in the Anthropocene

Riparian ecosystems are hotspots for ecological restoration globally because of the disproportionately high value and diversity of the ecological functions and services which they support and their high level of vulnerability to anthropogenic pressures, including climate change. Degraded riparian ecosystems are associated with many serious anthropogenic problems including increased river bank erosion, water quality decline, increased flood risk and biodiversity loss. Conventional approaches to riparian restoration, however, are frequently too narrow in focus – spatially, temporally, ecologically and socially – to adequately or equitably address the goals to which they aspire. Climate change, along with the intensification of other human pressures, means that static, historically oriented restoration objectives focused solely on prior ecological composition and structure are unlikely to be defensible, achievable or appropriate in the Anthropocene. Conversely, open‐ended restoration strategies lacking clear objectives and targets entail substantial risks such as significant biodiversity losses, especially of native species. A functional approach to planning and prioritising riparian restoration interventions offers an intermediate alternative that is still framed by measurable targets but allows for greater consideration of broader temporal, spatial and cultural influences. Here, we provide an overview of major riparian functions across multiple scales and identify key drivers of, and threats to, these. We also discuss practical approaches to restoring and promoting riparian functions and highlight some key concerns for the development of policy and management of robust riparian restoration in the Anthropocene.     

The importance of ecological memory for trophic rewilding as an ecosystem restoration approach

Increasing human pressure on strongly defaunated ecosystems is characteristic of the Anthropocene and calls for proactive restoration approaches that promote self‐sustaining, functioning ecosystems. However, the suitability of novel restoration concepts such as trophic rewilding is still under discussion given fragmentary empirical data and limited theory development. Here, we develop a theoretical framework that integrates the concept of ‘ecological memory’ into trophic rewilding. The ecological memory of an ecosystem is defined as an ecosystem's accumulated abiotic and biotic material and information legacies from past dynamics. By summarising existing knowledge about the ecological effects of megafauna extinction and rewilding across a large range of spatial and temporal scales, we identify two key drivers of ecosystem responses to trophic rewilding: (i) impact potential of (re)introduced megafauna, and (ii) ecological memory characterising the focal ecosystem. The impact potential of (re)introduced megafauna species can be estimated from species properties such as lifetime per capita engineering capacity, population density, home range size and niche overlap with resident species. The importance of ecological memory characterising the focal ecosystem depends on (i) the absolute time since megafauna loss, (ii) the speed of abiotic and biotic turnover, (iii) the strength of species interactions characterising the focal ecosystem, and (iv) the compensatory capacity of surrounding source ecosystems. These properties related to the focal and surrounding ecosystems mediate material and information legacies (its ecological memory) and modulate the net ecosystem impact of (re)introduced megafauna species. We provide practical advice about how to quantify all these properties while highlighting the strong link between ecological memory and historically contingent ecosystem trajectories. With this newly established ecological memory–rewilding framework, we hope to guide future empirical studies that investigate the ecological effects of trophic rewilding and other ecosystem‐restoration approaches. The proposed integrated conceptual framework should also assist managers and decision makers to anticipate the possible trajectories of ecosystem dynamics after restoration actions and to weigh plausible alternatives. This will help practitioners to develop adaptive management strategies for trophic rewilding that could facilitate sustainable management of functioning ecosystems in an increasingly human‐dominated world.     

Learning from scientific literature: Can indicators for measuring success be standardized in “on the ground” restoration?

The Society for Ecological Restoration (SER) Primer identifies key ecosystem attributes for evaluating restoration outcome. Broad attribute categories could be necessary due to the large variety of restoration projects, but could make overall evaluations and assessments challenging and might hamper the development of sound and successful restoration. In this study we carry out a systematic review of scientific papers addressing evaluation of restoration outcome. We include 104 studies published after 2010 from Europe or North America, representing different types of restoration projects in terrestrial and freshwater ecosystems. We explore the main ecological and socioeconomic attributes used to evaluate restoration outcome, and related indicators and specific methods applied to measure this, in relation to ecosystem and type of restoration project. We identify a wide range of indicators within each attribute, and show that very different methods are employed to measure them. This complexity reduces the opportunity for meaningful comparison and standardization of evaluation of restoration outcome, within and between ecosystems. Socioeconomic indicators are rarely used to evaluate restoration outcome, and studies including both ecological and socioeconomic indicators are nearly absent. Based on our findings we discuss whether standardization and streamlining of indicators is useful to improve the evaluation of “on the ground” restoration, or if this is not appropriate given the diversity of goals and ecosystems involved. Species‐specific traits are used in many projects and should be considered as an addition to the original SER attributes. Furthermore, we discuss the potential for restoration evaluation that encompasses not only assessment of ecological but also socioeconomic indicators.     

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.     

Riverine landscape dynamics and ecological risk assessment

1. The aim of ecological risk assessments is to evaluate the likelihood that ecosystems are adversely affected by human‐induced disturbance that brings the ecosystem into a new dynamic equilibrium with a simpler structure and lower potential energy. The risk probability depends on the threshold capacity of the system (resistance) and on the capacity of the system to return to a state of equilibrium (resilience). 2. There are two complementary approaches to assessing ecological risks of riverine landscape dynamics. The reductionist approach aims at identifying risk to the ecosystem on the basis of accumulated data on simple stressor–effect relationships. The holistic approach aims at taking the whole ecosystem performance into account, which implies meso‐scale analysis. 3. Landscape patterns and their dynamics represent the physical framework of processes determining the ecosystem's equilibrium. Assessing risks of landscape dynamics to riverine ecosystems implies addressing complex interactions of system components (e.g. population dynamics and biogeochemical cycles) occurring at multiple scales of space and time. 4. One of the most important steps in ecological risk assessment is to establish clear assessment endpoints (e.g. vital ecosystem and landscape attributes). Their formulation must recognise that riverine ecosystems are dynamic, structurally complex and composed of both deterministic and stochastic components. 5. Remote sensing (geo)statistics and geographical information systems are primary tools for quantifying spatial and temporal components of riverine ecosystem and landscape attributes. 6. The difficulty to experiment at the riverine landscape level means that ecological risk management is heavily dependent on models. Current models are targeted towards simulating ecological risk at levels ranging from single species to habitats, food webs and meta‐populations to ecosystems and entire riverine landscapes, with some including socio‐economic considerations.     

The MAES process in Italy: Contribution of vegetation science to implementation of European Biodiversity Strategy to 2020

Abstract

Target 2 of the European Biodiversity Strategy to 2020, whose aim was to maintain and restore ecosystems and their services, deals in practical terms with the mapping and assessment of ecosystems and their services, with the development of green infrastructure and with halting the loss of biodiversity at the EU, national, and subnational levels. The aim of this short communication was to show the activities currently being carried out in Italy that are related to this target, focusing on the contribution of vegetation science skills to the national implementation process. In particular, we outline noteworthy inputs in ecosystem mapping, in the assessment of ecosystem conservation status, in the individuation of priorities for the restoration of ecosystems, and in the settingup of an ecological framework to promote green infrastructure. An overview of the process outcomes and their relevance within the national and international contexts is also provided.     

湖泊生态服务受益者分析及生态生产函数构建

生态系统服务管理作为生态系统管理的优化方式,是生态学研究的前沿方向。湖泊生态系统服务管理是指综合利用生态学、经济学、社会学和管理学等学科知识,对影响湖泊生态系统结构、过程、功能的关键因子进行调控,提高湖泊生态系统服务供给水平和供给能力的过程。近年来国内外学者针对湖泊生态系统服务内涵、分类、经济价值评估等方面开展了大量研究,极大地促进了湖泊生态系统服务从认知走向管理实践。然而,现有研究在开展湖泊生态系统服务价值评估时多忽略生态系统服务受益者和生态系统特征对生态系统服务的边际影响分析,无法揭示生态系统服务空间流动和转移特征及生态系统服务时空权衡关系,制约了生态系统服务研究与管理决策和政策设计结合。在综述湖泊生态系统服务定量评估方法的基础上,认为通过生态系统服务受益者分析确定湖泊生态系统最终服务,并通过构建生态生产函数确定湖泊生态系统服务权衡关系及湖泊生态系统特征对生态系统最终服务的边际影响,是生态系统服务走向管理实践和政策设计的科学依据,可以确保生态、社会、经济可持续发展。     

On Sustainability, Estuaries, and Ecosystem Restoration: The Art of the Practical

Ecosystem restoration in highly complex, human‐dominated estuaries rests on a strong conceptual foundation of sustainability, ecosystems, and adaptive management of human‐induced environmental impacts. Successful application involves evaluating uncertainty, incorporating place‐based information, and engaging diverse constituencies in the planning process. That means integration of technical knowledge with an understanding of the “cultural milieu” inherent in all estuaries, that is, the intensity of human activity and impacts plus socioeconomic factors relevant to restoration goals. Operational definitions of what constitutes acceptable ecosystem conditions and current baselines are critical yet rest in large measure on cultural values and socioeconomic considerations. Resources for long‐term monitoring and research to assess performance and ecosystem condition are paramount. Unprecedented population growth promises additional stressors on estuarine environments worldwide, making maintenance of present conditions difficult. The art of good, practical ecosystem restoration as a management tool at multiple geographic scales promises to play a crucial role in sustainability goals.     

The SER Standards,cultural ecosystems,and the nature‐culture nexus—a reply to Evans and Davis

Evans and Davis claim the SER Standards use a “pure naturalness” model for restoration baselines and exclude most cultural ecosystems from the ecological restoration paradigm. The SER Standards do neither. The SER Standards consider both “natural” ecosystems (that are unequivocally not cultural) and “similar” cultural ecosystems as suitable reference models. Furthermore, Evans and Davis propose assessing whether a cultural ecosystem exhibits “good, bad, or neutral impacts from humans on ecosystems” as the basis for reference models. We argue that such an approach would overlook the indispensability of native ecosystem benchmarks to measure human impacts and provide a springboard for social‐ecological restoration.     

Beyond Paradise—Meeting the Challenges in Tropical Biology in the 21st Century

Tropical ecosystems support a diversity of species and ecological processes that are unparalleled anywhere else on Earth. Despite their tremendous social and scientific importance, tropical ecosystems are rapidly disappearing. To usher tropical ecosystems and the human communities dependent upon them through the environmental transformations of the 21st century, tropical biologists must provide critical knowledge in three areas: 1) the structure and function of tropical ecosystems; 2) the nature and magnitude of anthropogenic effects on tropical ecosystems; and 3) the socio‐economic drivers of these anthropogenic effects. To develop effective strategies for conservation, restoration, and sustainable management of tropical ecosystems, scientific perspectives must be integrated with social necessities. A new set of principles built on a framework for pursuing relevant tropical biological research will facilitate interdisciplinary approaches, integrate biological knowledge with the social sciences, and link science with policy. We propose four broad recommendations for immediate action in tropical biology and conservation that are fundamental to all biological and social disciplines in the tropics: 1) assemble and disseminate information on life's diversity in the tropics; 2) enhance tropical field stations and build a worldwide network to link them with tropical field biologists at their field sites; 3) bring the field of tropical biology to the tropics by strengthening institutions in tropical countries through novel partnerships between tropical and temperate zone institutions and scientists; and 4) create concrete mechanisms to increase interactions between tropical biologists, social scientists, and policy makers.     

Urban Grassland Restoration: A Neglected Opportunity for Biodiversity Conservation

Urbanization is one of the most severe threats to biodiversity, so why should not we use green space in cities to counteract the biodiversity loss as much as possible? Urban grasslands provide a large number of social, financial, recreational, and environmental ecosystem services but can also support high biodiversity. In this article, I describe the importance of urban grasslands for (local) biodiversity and recommend strengthening restoration ecological research and efforts to optimize these novel ecosystems for conservation purposes. The management intensity of a high proportion of urban grasslands decreased over the last decades. However, species richness of these grasslands is still low, although there is now a great potential for higher plant, but also animal diversity. While communal authorities are interested in cost‐efficient but at the same time biodiversity‐friendly management of urban grasslands, a well‐founded scientific basis for the restoration of urban grassland is still missing. I argue that besides all challenges associated with the restoration of urban habitats we should urgently proceed in the development of appropriate and effective restoration approaches and communicate knowledge gained to urban planners and stakeholders. Widening the scope of restoration ecological research to novel ecosystems such as urban grasslands is one of the most important recent challenges for biodiversity restoration and it gives urban habitats the significance they deserve .     

Insurance Value of Green Infrastructure in and Around Cities

The combination of climate change and urbanization projected to occur until 2050 poses new challenges for land-use planning, not least in terms of reducing urban vulnerability to hazards from projected increases in the frequency and intensity of climate extremes. Interest in investments in green infrastructure (interconnected systems of parks, wetlands, gardens and other green spaces), as well as in restoration of urban ecosystems as part of such adaptation strategies, is growing worldwide. Previous research has highlighted the insurance value of ecosystems in securing the supply of ecosystem services in the face of disturbance and change, yet this literature neglects urban areas even though urban populations are often highly vulnerable. We revisit the insurance value literature to examine the applicability of the concept in urban contexts, illustrating it with two case studies: watersheds providing drinking water for residents of Vancouver, Canada; and private gardens ensuring connectedness between other parts of urban green infrastructure in London, UK. Our research supports the notion that investments in green infrastructure can enhance insurance value, reducing vulnerability and the costs of adaptation to climate change and other environmental change. Although we recommend that urban authorities consider the insurance value of ecosystems in their decision-making matrix, we advise caution in relying upon monetary evaluations of insurance value. We conclude by identifying actions and management strategies oriented to maintain or enhance the insurance value of urban ecosystems. Ecosystems that are themselves resilient to external disturbances are better able to provide insurance for broader social–ecological systems.     

Restoration for multiple use

Management of restored ecosystems for multiple use is a modern necessity given a growing human population and dwindling supplies of ecosystem goods and services. Multiple use management refers to managing resources simultaneously for sustainable output of many goods and services. Within any restoration, thoughtful planning and early stakeholder engagement can help harmonize seemingly competing multiple uses. Although the field of ecological restoration is young and there are few long‐term lessons to draw from, we can infer from ecological theory that maximization of native biodiversity can impart resilience in the restored ecosystem and can buffer against the stress of multiple use management. Restoration for multiple use should be accompanied with an acknowledgment that humility is required and monitoring is needed to keep the restored ecosystem on an acceptable trajectory. The field of ecological restoration was founded upon the notion that ecosystems would be restored for ethical reasons, but modern realities have necessitated a more utilitarian approach to restoration that requires restoring ecosystems for multiple uses. This reality represents a grand challenge for the next generation of restoration ecologists.     

Resilience and restoration of tropical and subtropical grasslands,savannas, and grassy woodlands

Despite growing recognition of the conservation values of grassy biomes, our understanding of how to maintain and restore biodiverse tropical grasslands (including savannas and open‐canopy grassy woodlands) remains limited. To incorporate grasslands into large‐scale restoration efforts, we synthesised existing ecological knowledge of tropical grassland resilience and approaches to plant community restoration. Tropical grassland plant communities are resilient to, and often dependent on, the endogenous disturbances with which they evolved – frequent fires and native megafaunal herbivory. In stark contrast, tropical grasslands are extremely vulnerable to human‐caused exogenous disturbances, particularly those that alter soils and destroy belowground biomass (e.g. tillage agriculture, surface mining); tropical grassland restoration after severe soil disturbances is expensive and rarely achieves management targets. Where grasslands have been degraded by altered disturbance regimes (e.g. fire exclusion), exotic plant invasions, or afforestation, restoration efforts can recreate vegetation structure (i.e. historical tree density and herbaceous ground cover), but species‐diverse plant communities, including endemic species, are slow to recover. Complicating plant‐community restoration efforts, many tropical grassland species, particularly those that invest in underground storage organs, are difficult to propagate and re‐establish. To guide restoration decisions, we draw on the old‐growth grassland concept, the novel ecosystem concept, and theory regarding tree cover along resource gradients in savannas to propose a conceptual framework that classifies tropical grasslands into three broad ecosystem states. These states are: (1) old‐growth grasslands (i.e. ancient, biodiverse grassy ecosystems), where management should focus on the maintenance of disturbance regimes; (2) hybrid grasslands, where restoration should emphasise a return towards the old‐growth state; and (3) novel ecosystems, where the magnitude of environmental change (i.e. a shift to an alternative ecosystem state) or the socioecological context preclude a return to historical conditions.     

城市生态系统修复研究进展

城市生态系统是社会-经济-自然复合生态系统。城市生态系统修复的实质是协调好城市复合生态系统的自然过程、经济过程和社会过程之间的关系,促进复合生态系统的各方面协调高效可持续发展。以城市绿地、城市湿地、城市废弃地三类主要的城市生态空间为对象,论述了城市生态系统修复的研究进展,提出当前城市生态系统修复存在以人工修复技术为主、自然修复不足、机理和量化研究缺乏、理论和应用脱节、管理机制不健全、复合生态系统理论体现不足等问题。梳理了当前城市生态系统修复的研究热点,包括城市生态系统修复机理、城市生态资产与生态系统服务、城市生态系统质量和健康、问题导向的生态修复、面向人类福祉的生态修复、生态修复多学科融贯,以及新方法和新技术的应用等几个方面。提出了城市生态修复与管理的相关对策和建议,可为我国城市生态系统修复的研究和实践提供参考。