Ecosystem structure, function, and restoration success: Are they related?

A direct relationship between ecosystem structure and function has been widely accepted by restoration ecologists. According to this paradigm, ecosystem degradation and aggradation represent parallel changes in structure and function, restoration following the same path as spontaneous succession. But the existence of single bidirectional trajectories and endpoints is not supported by empirical evidence. On the contrary, multiple meta-stable states, irreversible changes and hysteresis are common in nature. These situations are better described by state-and-transition models. Merging those models into the structure–function framework may help to develop new hypotheses on ecosystem dynamics, and may provide a suitable framework for planning restoration activities. We use the relationship between ecosystem function and the effort needed to restore a degraded ecosystem (i.e. restorability) as an example. A linear relationship between ecosystem structure and function suggests that ecosystem degradation and restorability are directly related. This may not be true when multiple states, not necessarily connected, are considered. We show two case studies that support this point, and discuss the implications of the incorporation of state-and-transition models into the structure–function framework on relevant topics of restoration ecology and conservation biology, such as the choice of reference ecosystems, the evaluation of restoration actions, and the identification of priority areas for conservation and restoration.     

Monitoring and evaluating large-scale, ‘open-ended’ habitat creation projects: A journey rather than a destination

Ecological restoration frequently involves setting fixed species or habitat targets to be achieved by prescribed restoration activities or through natural processes. Where no reference systems exist for defining outcomes or where restoration is planned on a large spatial scale, a more ‘open-ended’ approach to defining outcomes may be appropriate. Such approaches require changes to the definition of goals and the design of monitoring and evaluation activities. We suggest that in open-ended projects restoration goals should be framed in terms of promoting natural processes, mobile landscape mosaics and improved ecosystem services. Monitoring can then focus on the biophysical processes that underpin the development of habitat mosaics and the provision of ecosystem services, on the way habitat mosaics change through time and on species that can indicate the changing landscape attributes of connectivity and scale. Stakeholder response should be monitored since an open-ended restoration approach is unusual and can encounter institutional and societal constraints. Evaluation should focus on reporting changing restoration impacts and benefits rather than on achieving a pre-defined concept of ecological success.     

Riparian Restoration in the Western United States: Oveview and Perspecive

This historical and conceptual overview of riparian ecosystem restoration discusses how riparian ecosystems have been defined, describes the hydrologic, geomorphic, and biotic processes that create and maintain riparian ecosystems of the western USA, identifies the main types of anthropogenic desturbances occurring in these ecosystems, and provides an overview of restoration methods for each disturbance type. We suggest that riparian ecosystems consist of two zones: Zone I occupies the active floodplain and is frequently inundated and Zone II extends from the active floodplain to the valley wall. Successful restoration depends n understanding the physical and biological processes that influence natural riparian ecosystems and the types of disturbance that have degraded riparian areas. Thus we recommend adopting a process-based approach for riparian restoration. Disturbances to riparian ecosystems in the western USA result from streamflow modifications by dams, reservoirs, and diversions; stream channelization; direct modification of the riparian ecosystem; and watershed disturbances. Four topics should be addressed to advance the state of science for restoration of riparian ecosys-tems: (1) interdisciplinary approaches, (2) a unified framework, (3) a better understanding of fundamental riparian ecosystem processes, and (4) restoration po-tential more closely related to disturbance type. Three issues should be considered regarding the cause of the degraded environment: (1) the location of the causative disturbance with respect to the degraded riparian area, (2) whether the disturbance is ongoing or can be elim-inated, and (3) whether or not recovery will occur nat-urally if the disturbance is removed.     

喀斯特脆弱生态系统复合退化控制与重建模式

以西南喀斯特地区为例,通过总结前人的研究成就和采集中国科学院亚热带农业生态研究所喀斯特生态实验站部分收集整理和试验数据,系统分析了喀斯特脆弱生态系统及其退化的机理,从"人-自然-经济复合生态系统"的观点出发,以干扰程度、群落类型、服务功能、土地退化和贫困状况为指标,创新性地提出了喀斯特脆弱生态系统的复合退化模式(含4个阶段),运用现代生态恢复学原理、方法和现代管理学创新理论,建立了喀斯特脆弱生态系统复合退化的控制模型.以此为基础,在喀斯特石山区、半石山区和土山丘陵区3个区域环境尺度范围内,针对性地建立了生态保护型、外向经济型和双三重螺旋3种生态恢复与重建模式,以促进喀斯特区域生态、经济、社会的全面协调与可持续发展.     

恢复及演替过程中的土壤生态学考虑

 人类社会的日益扩张,导致人类加速占据地球表面景观,并胁迫地球上生态系统提供不断增长的资源需求和废物吸收能力。所以保护尚未“开放”的自然生态系统及恢复退化的生态系统成为人类长期生存的重要保证。该文着重讨论了恢复过程中的土壤生态学问题。土壤是所有陆地生态系统的结构与功能基础。土壤微生物与动物的种群变化,土壤有机质的积累,及主要元素地球化学循环的改变是恢复生态的重要环节。生态恢复与演替有许多共性,所以演替理论对于认识生态系统恢复中的结构与功能变化有着很大帮助。与自然演替不同的是,人的积极参与在生态恢复中占有中心位置。从最初样地的确立与物种的选择,到后续的灌溉与施肥管理,人的选择影响着土壤的演化,生态系统的发展方向,和最终恢复生态的结果。为保障恢复生态系统的可持续性,短期的工作目标,如提供养分促进植物生长,务必与长期的工作目标,如土壤的恢复相结合。植物与土壤的相互反馈是生态恢复成功的重要标志。成功的生态恢复不仅是对现有生态学理论的“试金检验”,也是推动生态学学科发展的重要原动力。     

Mapping the information landscape of the United Nations Decade on Ecosystem Restoration Strategy

The strategy of the United Nations Decade on Ecosystem Restoration identifies three pathways for action for overcoming six global barriers thought to hamper upscaling. We evaluated 6,023 peer-reviewed and gray literature papers published over the last two decades to map the information landscape underlying the barriers and associated pathways for action across world regions, terrestrial ecosystem types, restorative interventions and their outcomes. Overall, the literature addressed more the financial and legislative barriers than the technical and research-related ones, supporting the view that social, economic and political factors hamper scaling up ecosystem restoration. Latin America, Africa, and North America were the most prominent regions in the literature, yet differed in the number of publications addressing each barrier. An overwhelming number of publications focused on forests (78%), while grasslands (6%), drylands (3%), and mangroves (2%) received less attention. Across the three pathways for action, the action lines on (1) promoting long-term ecosystem restoration actions and monitoring and (2) education on restoration were the most underrepresented in the literature. In general, restorative interventions assessed rendered positive outcomes except those of a political, legislative or financial nature which reported negative or inconclusive outcomes. Our indicative assessment reveals critical information gaps on barriers, pathways, and types of restorative interventions across world regions, particularly related to specific social issues such as education for ecosystem restoration. Finally, we call for refining “strength of evidence” assessment frameworks that can systematically appraise, synthesize and integrate information on traditional and practitioner knowledge as two essential components for improving decision-making in ecosystem restoration.     

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.     

Effects of Stream Restoration on Woody Riparian Vegetation of Southern Appalachian Mountain Streams,North Carolina,U.S.A

Riparian revegetation, such as planting woody seedlings or live stakes, is a nearly ubiquitous component of stream restoration projects in the United States. Though evaluations of restoration success usually focus on in‐stream ecosystems, in order to understand the full impacts of restoration the effects on riparian ecosystems themselves must be considered. We examined the effects of stream restoration revegetation measures on riparian ecosystems of headwater mountain streams in forested watersheds by comparing riparian vegetation structure and composition at reference, restored, and degraded sites on nine streams. According to mixed model analysis of variance (ANOVA), there was a significant effect of site treatment on riparian species richness, basal area, and canopy cover, but no effect on stem density. Vegetation characteristics at restored sites differed from those of reference sites according to all metrics (i.e. basal area, canopy cover, and species composition) except species richness and stem density. Restored and degraded sites were structurally similar, with some overlap in species composition. Restored sites were dominated by Salix sericea and Cornus amomum (species commonly planted for revegetation) and a suite of disturbance‐adapted species also dominant at degraded sites. Differences between reference and restored sites might be due to the young age of restored sites (average 4 years since restoration), to reassembly of degraded site species composition at restored sites, or to the creation of a novel anthropogenic ecosystem on these headwater streams. Additional research is needed to determine if this anthropogenic riparian community type persists as a resilient novel ecosystem and provides valued riparian functions.     

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.     

Restoration Ecology to the Future: A Call for New Paradigm

The discipline of restoration ecology has grown remarkably in the past decades, providing new ideas and opportunities for conserving biological diversity, managing ecosystems, and testing ecological theories. On the other side, its past‐oriented, static, and idealistic approach has been criticized for subjectivity in determining restoration goals, inapplicability to dynamic ecosystems, and inability for restoring certain irreversible losses. Moreover, unpredictable sustainability of the restored ecosystems, which were modeled after its historical fidelity, adds our skepticism under the changing environment. This paper calls for a new paradigm of ecological restoration to the future. A future‐oriented restoration should (1) establish the ecosystems that are able to sustain in the future, not the past, environment; (2) have multiple alternative goals and trajectories for unpredictable endpoints; (3) focus on rehabilitation of ecosystem functions rather than recomposition of species or cosmetics of landscape surface; and (4) acknowledge its identity as a “value‐laden” applied science within economically and socially acceptable framework. Applicability of ecological theories to restoration practice is also discussed in this paper.     

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.     

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.     

半干旱区生态恢复关键生态系统识别——以内蒙古自治区和林县为例

我国土地退化严重,且大部分发生在干旱半干旱地区.恢复为何种生态系统类型是生态学研究的重要课题.采用生态功能区划,根据各个生态功能区主体生态系统功能,推导发挥此功能的生态系统类型的方法,识别关键生态系统类型.以内蒙古自治区和林县为例,采用文献调研、实地调查、3S技术等方法,在评价该县生态敏感性、生态服务功能重要性的基础上,将该县划分为3个一级生态区,11个二级生态功能区.根据各个生态功能区的主体生态系统服务功能,分析发挥该功能的可能生态系统类型.再根据全国自然植被区划、气候变化趋势模型以及现状植被类型,识别各个生态功能区的关键生态系统类型.     

地下生态系统对生态恢复的影响

生态系统破坏与退化的加剧使生态恢复成为全球性的挑战课题,近年来生态恢复的研究已逐渐由地上向地下部分转移,地下部分对生态系统退化所起的作用、机理和过程已倍受关注。本文通过探讨恢复生态学的关键概念,从土壤、地下水循环、生物系统3个方面探讨了地下生态系统对生态恢复的作用机理和反馈机制。针对目前的研究现状,指出地下生态系统研究中存在的问题,并提出今后需要深入研究的几个方向:1)生态系统退化程度的诊断及其标准;2)基于诊断标准,针对不同退化生态系统类型选定恢复的目标植物群落,如何改善土壤性质,确定土壤性质的改善程度;确定地下水位及土壤含水量的阈值;如何有效选择、引入和接种土壤生物;3)生态系统地上和地下部分整合及恢复过程中监测指标的确定。     

The potential of earthworms to restore ecosystem services after opencast mining – A review

Opencast coal mining has several environmental impacts, which require land rehabilitation when mining operations are finished. For that reason, restoration after such extractive industries’ work is common and has been well studied. However, many ecological restoration schemes do not examine to what extent complete and functioning ecosystems have been restored above and below ground. While the aim should be to restore functioning ecosystems, most restoration plans focus only on vegetation and above ground macro-fauna.Among the potential species that are likely to be important early in mine land restoration, earthworms are particularly good candidates. They provide several ecosystem services that are likely to accelerate soil restoration, improve primary production and facilitate the restoration of a functional ecosystem in mining areas. These services include the following: increase in topsoil fertility, food for a wide range of predators and recycling of waste organic materials on rehabilitated areas.Here, we outline some of the challenges specifically facing opencast mining restoration and describe how the ecosystem services provided by earthworms may address some of these challenges.     

喀斯特石漠化综合治理及其区域恢复效应

国家加大生态保护与建设力度背景下,我国西南喀斯特石漠化面积实现"持续净减少",面临由传统高强度人为干扰向大规模自然恢复与人工造林的转变,石漠化治理也面临转型。现有喀斯特生态研究已阐明了喀斯特脆弱生态系统人为干扰退化机制,初步揭示了生态治理改善生态系统结构与功能的恢复机理,突破了保土集水与植被恢复的适应性石漠化治理技术与模式,评估了石漠化治理显著加速区域植被生长与恢复的固碳效应。但目前石漠化治理面临着治理成效巩固困难、治理技术与模式缺乏区域针对性、大规模低效人工林亟待改造、社会人文驱动机制不清等问题。未来喀斯特生态恢复应聚焦石漠化治理提质增效,从侧重单一生态要素、单一生态过程的研究向多要素综合、多过程综合以及喀斯特地表-地下过程耦合、景观格局与生态过程耦合、生态过程与生态系统服务耦合、自然与人文过程耦合等陆地表层系统集成的方向发展,为我国西南喀斯特地区石漠化治理与扶贫开发成效巩固、乡村振兴与美丽中国战略的实施提供科技支撑。     

Linking biodiversity indicators,ecosystem functioning,provision of services and human well-being in estuarine systems: Application of a conceptual framework

Assuming that human well-being strongly relies on the services provided by well-functioning ecosystems, changes in the ecological functioning of any system can have direct and indirect effects on human welfare. Intensive land use and tourism have expanded in recent decades along coastal ecosystems, together with increasing demands for water, food and energy; all of these factors intensify the exploitation of natural resources. Many of the interrelations between ecosystem functioning and the provision of ecosystem services (ES) still require quantification in estuarine systems. A conceptual framework to assess such links in a spatially and temporally explicit manner is proposed and applied to the Mondego estuary (Portugal). This framework relies on three consecutive steps and discriminates among biodiversity structural components, ecosystem functioning and stability and the services provided by the ecosystem.Disturbances in abiotic factors were found to have a direct effect on biodiversity, ecosystem functioning and the provision of ES. The observed changes in the species composition of communities had a positive effect on the ecosystem's productivity and stability. Moreover, the observed changes in the estuarine ES provision are likely to arise from changing structural and abiotic factors and in the present case from the loss or decline of locally abundant species. This study also indicates that linear relationships between biodiversity, ecosystem functioning and services provision are unlikely to occur in estuarine systems. Instead, cumulative and complex relations are observed between factors on both temporal and spatial scales. In this context, the results suggest several additional conclusions: (1) biodiversity and ecosystem functioning interaction with human well-being need to be incorporated into decision-making processes aimed at the conservative management of systems; (2) the institutional use of research results must be part of the design and implementation of sustainable management activities; and (3) more integrative tools/studies are required to account for the interactions of estuarine ecosystems with surrounding socio-economic activities. Therefore, when performing integrated assessments of ecosystem dynamics, it becomes essential to consider not only the effects of biodiversity and ecosystem functioning on services provision but also the effects that human well-being and ES provision may have on estuarine biodiversity and ecosystem functioning.The proposed framework implies taking into account both the functional and the commodities points of view upon natural ecosystems and by this representing a line of thought which will deserve further research to explore more in detail the conceptual links between biodiversity–ecosystem functioning–services provided.     

惠州西湖游浮植物群落对生态系统修复的响应

2004年对广东惠州西湖实施了生态系统修复示范工程,示范区目前沉水植物丰富,水体常年清澈见底。通过2008年6月至2009年5月对示范区和未进行生态修复的平湖逐月进行浮游植物调查,研究了浮游植物群落对湖泊生态系统修复的响应。结果表明,与未修复的平湖相比,示范区浮游植物数量及群落结构均发生了很大变化。示范区全年浮游植物平均生物量和细胞丰度分别为0.31 mg/L和2.75×106cells/L,均远低于未修复的平湖的3.27 mg/L和197.46×106cells/L;平湖中蓝藻在全年大部分时间占有绝对优势,一些热带富营养化水体中的代表种类（假鱼腥藻）成为优势种类;而示范区蓝藻不占优势,取而代之的是一些隐藻、硅藻和甲藻门的种类。另外,示范区浮游植物丰富度增加,年平均Margalef物种丰富度指数为3.70,显著高于平湖的2.68。因此,重建以沉水生植物为优势的生态系统是抑制浮游植物发展和改善湖泊水环境的有效途径。     

A management approach for the ecological integrity of NE Atlantic estuaries

A method to evaluate the ecological integrity of estuaries at a biogeographical scale is presented. Based on a conceptualisation which systematically establishes how human uses and stressors affect ecosystem functioning, the method allows for regional evaluations of the effect produced by human impacts on the ecological integrity. Comparisons across nine medium size estuaries (Bay of Biscay) showed major alterations in the connectivity (>65% of estuaries) and tidal dynamics (>55% of estuaries) in NE Atlantic estuaries. Likewise, the results obtained highlighted physical barriers such as dykes and land reclamation as the main hydromorphological stressors threatening the ecological integrity. The methodological approach was validated at a restored estuary. The validation primarily confirmed the ability of the conceptual model to identify the main stressors threatening the ecological integrity in estuaries. Secondly, it allowed the identification of the most suitable restoration solutions. Thirdly, it emphasised the importance of the hydrological dynamics to recover the ecosystem's ecological integrity.     

Monitoring ecological processes for restoration projects

Restoration of ecological processes is key to restoring the capacity of ecosystems to support social, economic, cultural and aesthetic values. The sustainability of the restored system also depends on processes associated with carbon, nutrient and hydrologic cycles, yet most restoration monitoring is limited to plant community composition. Our research has shown that short-term plant composition monitoring is a necessary but insufficient predictor of long-term restoration success. Long-term (up to 75 years) studies in the western United States show that short-term monitoring of plant community composition alone incorrectly predicted the failure of treatments that were ultimately successful, and the success of treatments that ultimately failed. We propose that vegetation composition monitoring be combined with one or more ecological process indicators reflecting changes in three fundamental ecosystem attributes on which restoration success depends: soil and site stability, hydrologic function and biotic integrity. These simple, rapid, plot-level indicators reflect changes in resource redistribution and vegetation structure. We include a case study involving restoration of mixed grass prairie on mineland in the west-central United States.