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1.
Intact drylands are highly evolved and complex ecosystems, which allow them to be productive despite harsh environmental conditions. However, drylands are particularly susceptible to degradation, even after minor disturbance events. Conditions for natural plant recruitment in dryland systems are spatially and temporally irregular, which can create challenges for restoration. Large-scale restoration and rehabilitation of dryland ecosystems have become a global concern, prompted by ever-increasing anthropogenic pressure and associated degradation of these natural systems worldwide. The success of plant reestablishment programs in these regions is closely linked to both ecological and socioeconomic opportunities and limitations. This special issue brings together papers that discuss the roles which ecological and socioeconomic factors play in influencing dryland ecosystem restoration outcomes. We aim to (1) highlight the current status of recovery efforts taking place across a range of dryland ecosystems, emphasize advances in the region-specific understanding of plant community development, and (2) provide comparisons between the primary drivers and limitations to restoration that exist across dryland systems.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
Human livelihood needs and nature conservation often contradict. Yet, healthy ecosystems are crucial for human livelihood quality. The semi-arid regions of East Africa suffer under demographic pressure and soil depletion. Ecosystem degradation becomes particularly visible along rivers in semiarid regions of south-east Kenya, where former pristine riparian forests have been transformed into agricultural fields and settlements with negative effects on ecosystem services. In this study, we aim to understand how local smallholders perceive the challenges for the riparian ecosystems and what factors affect their engagement in environmental conservation. We surveyed about 200 farmers and performed expert interviews with representatives from governmental institutions from the field of land- and resource management along Nzeeu River in south-east Kenya. We assessed the level of education, land use practices, environmental knowledge, attitudes and the willingness to contribute to nature conservation. We tested for spatial bias to understand smallholders’ perceptions on environmental challenges. Our data show that land division due to inheritance is not perceived as a problem by the farmers. However, owners holding?<?1 ha of land property are less willing to spare some of their land for conservation, as opposed to those holding land plots above this size. Despite a high level of general willingness to conserve ecosystems, our data underline that local people hardly actively engage in conservation action. Furthermore, our data indicate a communication gap between local smallholders and regional governmental officers as well as overconfidence in mass media through the radio which can contradict successful adoption of pro-environment behavior. Sustainable land management in our study area is not a matter of education, but depends from the size of land property. There is an urgent need to bridge this communication gap, as a prerequisite to improve sustainable land management.  相似文献   

5.
高寒草甸是青藏高原的主体植被类型,但退化态势较为严峻,严重威胁青藏高原生态屏障的战略地位。退化高寒草甸的复健是世界性难题,治理效果也因退化状态、恢复措施及气候环境而异。以春季休牧、秋季休牧、畜群结构优化、减畜轮牧、围栏封育及翻耕改建等典型多途径恢复措施下的退化高寒草甸为对象,系统探讨主要生态要素和生态功能的响应特征及潜在过程。结果表明,典型恢复措施下退化高寒草甸的植被生产力、土壤有机碳密度及土壤饱和持水量等生态要素都得到一定程度的提升,而恢复效果与实施年限及恢复措施密切相关。围栏封育和翻耕改建下土壤有机碳密度及饱和持水量随恢复年限均表现为对数饱和型的响应特征,退化高寒草甸固碳持水功能的基本恢复年限约为6—10年。春季休牧、秋季休牧、畜群结构优化、减畜轮牧、围栏封育等放牧管理恢复措施应适用于轻度退化至重度退化的高寒草甸,而翻耕改建则是极度退化高寒草甸的适宜治理措施。由于多途径恢复措施的关注目标不同,今后研究应集中在恢复措施的组合优化和综合评价等方面。  相似文献   

6.
淡水湖泊生态系统退化驱动因子及修复技术研究进展   总被引:7,自引:0,他引:7  
王志强  崔爱花  缪建群  王海  黄国勤 《生态学报》2017,37(18):6253-6264
目前我国多数淡水湖泊污染、退化问题非常严重,诸多修复技术也已初见成效。影响淡水湖泊生态系统退化的驱动因子众多,既有生物因素也有非生物因素,它们之间相互联系,相互作用,且作用机理错综复杂。首先介绍了淡水湖泊生态系统退化的含义及形式;其次,分析、总结了淡水湖泊生态系统退化的驱动因子,从退化的生态学完整性意义和退化修复的技术手段上看,淡水湖泊生态系统主要受物理、化学和生物三大驱动因子影响,且基本遵循"环境变化-驱动力-压力(阈值)-状态-响应"原理;再次,在厘清湖泊生态系统退化驱动原理的基础上,从淡水湖泊生态系统功能模块和湖泊生态系统修复实践经验总结的角度出发,构建了淡水湖泊生态系统修复模块技术体系,并就湖泊富营养化和湖滨湿地生态系统退化修复的技术进行了讨论和对比;最后,对淡水湖泊生态系统修复的环境变化驱动因子的作用机制、作用途径和修复技术的长效机制等方面进行了展望。  相似文献   

7.
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.  相似文献   

8.
张云芝  胡云锋  韩月琪  战胜 《生态学报》2021,41(19):7599-7613
掌握生态退化区和研究热点区的空间分布、退化区生态系统的演变态势是认识生态问题、开展生态治理的基础,但目前缺乏全球主要生态退化区空间分布图等基础数据和相关知识。应用多源数据集成融合、长时序卫星遥感分析、互联网文献大数据建模分析等方法,对以荒漠化、水土流失、石漠化为代表的全球主要生态退化类型区的空间分布、演变态势、研究关注热度等进行了研究。结果表明:(1)全球荒漠化区面积约15.4×106 km2,水土流失区面积约14.3×106 km2,石漠化区面积约1.1×106 km2;这些生态退化区主要分布在非洲撒哈拉沙漠南北边缘,欧洲西部、地中海沿岸、东欧平原南部,南亚印度河流域,中国西北地区、云贵高原,北美洲落基山脉以及南美洲阿根廷等地区。(2)2000年以来,上述退化区中约有3.9%的面积处于退化加重态势,73.3%的面积处于脆弱平衡状态,22.8%的区域出现好转趋势。(3)全球生态退化研究热点区的分布与全球生态退化区的分布总体呈现一致性。但在沙特阿拉伯中部、哈萨克斯坦北部,巴西大部,安哥拉、南非等生态退化区,存在生态系统继续恶化、缺乏研究界足够关注的情况。研究成果深化了对全球主要生态退化区分布格局的认识,对于防范全球发展和建设中出现加重的生态退化等具有参考价值。  相似文献   

9.
Grazing lands are the most degraded land use type in the world, particularly in arid and semiarid areas, as a result of improper human activities such as overgrazing coupled with drought. For restoration of degraded grazing lands, large-scale projects are implemented, which include extensive vegetation improvements (e.g., reseeding, weed control, shrub plantations, reforestations, etc.). Such interventions, apart from being very expensive, often create environmental problems. In situations where the abiotic function of the degraded grazing land has not been irreversibly damaged, application of appropriate grazing management is an ecologically viable solution to their restoration. This is especially necessary for grazed lands with a long history of grazing by large herbivores, including livestock. Excluding domestic animals from such ecosystems may lead to several ecological problems such as loss of biodiversity and devastating wildfires. Appropriate grazing management should include an adjusted stocking rate to the grazing capacity of the restored land, the right kind of animal species, and an appropriate grazing system. In addition, grazing management should be implemented on the basis of a plan that is part of the restoration project. It is concluded that grazing management should become a priority option in restoration of the biotic function of degraded grazing lands, especially in those that have had a long history with the presence of domestic animals.  相似文献   

10.
Spatial prioritization techniques are commonly used in conservation planning, but are relatively new for planning restoration programs. Typically, ecological data, and more recently data on economic costs and vulnerability of sites, are used. However, the effectiveness of restoration action ultimately relies on a combination of the appropriate ecological restoration techniques and the human and social dynamics of social‐ecological systems. Surveys were conducted with 29 land managers within the Makana Municipality of the Eastern Cape, South Africa, to identify a range of human and social factors hypothesized to define the potential effectiveness of restoration action. Land managers with similar characteristics were grouped using a cluster analysis, and the groups ranked and mapped in geographical information system (GIS) to provide a spatial representation of restoration opportunity. The total number of questions were reduced by 35.6%, a step toward developing a rapid assessment approach for assessing land managers' potential participation in restoration initiatives. Identifying and incorporating human and social factors that directly influence restoration prioritization should promote efficient and effective implementation of restoration actions by the Working for Woodlands programme, who are looking to funding landscape‐scale restoration through carbon trading.  相似文献   

11.
1.  The provision of environmental flows and the removal of barriers to water flow are high priorities for restoration where changes to flow regimes have caused degradation of riverine ecosystems. Nevertheless, flow regulation is often accompanied by changes in catchment and riparian land-use, which also can have major impacts on river health via local habitat degradation or modification of stream energy regimes.
2.  The challenges are determining the relative importance of flow, land-use and other impacts as well as deciding where to focus restoration effort. As a consequence, flow, catchment and riparian restoration efforts are often addressed in isolation. River managers need decision support tools to assess which flow and catchment interventions are most likely to succeed and, importantly, which are cost-effective.
3.  Bayesian networks (BNs) can be used as a decision support tool for considering the influence of multiple stressors on aquatic ecosystems and the relative benefits of various restoration options. We provide simple illustrative examples of how BNs can address specific river restoration goals and assist with the prioritisation of flow and catchment restoration options. This includes the use of cost and utility functions to assist decision makers in their choice of potential management interventions.
4.  A BN approach facilitates the development of conceptual models of likely cause and effect relationships between flow regime, land-use and river conditions and provides an interactive tool to explore the relative benefits of various restoration options. When combined with information on the costs and expected benefits of intervention, one can derive recommendations about the best restoration option to adopt given the network structure and the associated cost and utility functions.  相似文献   

12.
The foundation of ecological restoration is how to preserve biocoenoses (i.e. functional ecosystems) and how to restore and reconstruct them where they were destroyed. One of the most important challenges is the restoration of complex, multilayer forests representing the potential natural vegetation. Native forests have functions in disaster mitigation and environmental protection, as well as providing the basis of existence for local people and maintaining gene pools for the future. Through vegetation surveys in Japan and South-east Asia, we have established basic principles in vegetation-ecological restoration of forests. We have been restoring expected disaster-mitigation and environmental protection forests, as experimental reforestation projects, since the 1970s at more than 750 sites throughout the 3000km long Japanese Archipelago, and since the 1980s in parts of South-east Asia, China and South America. The restoration movement has spread from a local activity to a global movement. We aim for the sustainable development of human society through ecological restoration of living environments.  相似文献   

13.
Drylands encompass over 40% of terrestrial ecosystems and face significant anthropogenic degradation causing a loss of ecosystem integrity, services, and deterioration of social‐ecological systems. To combat this degradation, some dryland restoration efforts have focused on the use of biological soil crusts (biocrusts): complex communities of cyanobacteria, algae, lichens, bryophytes, and other organisms living in association with the top millimeters of soil. Biocrusts are common in many ecosystems and especially drylands. They perform a suite of ecosystem functions: stabilizing soil surfaces to prevent erosion, contributing carbon through photosynthesis, fixing nitrogen, and mediating the hydrological cycle in drylands. Biocrusts have emerged as a potential tool in restoration; developing methods to implement effective biocrust restoration has the potential to return many ecosystem functions and services. Although culture‐based approaches have allowed researchers to learn about the biology, physiology, and cultivation of biocrusts, transferring this knowledge to field implementation has been more challenging. A large amount of research has amassed to improve our understanding of biocrust restoration, leaving us at an opportune time to learn from one another and to join approaches for maximum efficacy. The articles in this special issue improve the state of our current knowledge in biocrust restoration, highlighting efforts to effectively restore biocrusts through a variety of different ecosystems, across scales and utilizing a variety of lab and field methods. This collective work provides a useful resource for the scientific community as well as land managers.  相似文献   

14.
Restoration of Biodiversity and Ecosystem Services on Agricultural Land   总被引:3,自引:0,他引:3  
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.  相似文献   

15.
In their article “Assessing the evidence base for restoration in South Africa,” Ntshotsho et al. attempt to determine whether restoration in South Africa is evidence based by reporting on 10 projects' baseline data collection, goal setting, and monitoring. However, their contribution suffers from two major constraints. First, they confuse assessing the evidence base with assessing whether restoration is evidence based. Truly, assessing the evidence base would entail a systematic review of the quantity and quality of information available as well as the conclusions supported, perhaps in a meta‐analytical framework. Determining if restoration is evidence based would require a survey of project managers to evaluate if they take decisions based on scientific information. Second, Ntshotsho et al. do not clearly distinguish successfully achieving restoration project goals from successfully restoring ecosystems. They largely focus on projects' socioeconomic goals without emphasizing that these goals are, by definition, secondary to ecological goals in determining restoration success. Thus, Ntshotsho et al. provide neither a sound assessment of the evidence base for restoration nor whether restoration is evidence based. To evaluate and encourage evidence‐based restoration in South Africa, we recommend a simple assessment of the basis on which restoration managers make decisions, identification of factors precluding evidence‐based decision‐making, and development of platforms to evaluate the data collected in restoration programs to generate an evidence base from which to make defendable decisions.  相似文献   

16.
Large vertebrates are strong interactors in food webs, yet they were lost from most ecosystems after the dispersal of modern humans from Africa and Eurasia. We call for restoration of missing ecological functions and evolutionary potential of lost North American megafauna using extant conspecifics and related taxa. We refer to this restoration as Pleistocene rewilding; it is conceived as carefully managed ecosystem manipulations whereby costs and benefits are objectively addressed on a case-by-case and locality-by-locality basis. Pleistocene rewilding would deliberately promote large, long-lived species over pest and weed assemblages, facilitate the persistence and ecological effectiveness of megafauna on a global scale, and broaden the underlying premise of conservation from managing extinction to encompass restoring ecological and evolutionary processes. Pleistocene rewilding can begin immediately with species such as Bolson tortoises and feral horses and continue through the coming decades with elephants and Holarctic lions. Our exemplar taxa would contribute biological, economic, and cultural benefits to North America. Owners of large tracts of private land in the central and western United States could be the first to implement this restoration. Risks of Pleistocene rewilding include the possibility of altered disease ecology and associated human health implications, as well as unexpected ecological and sociopolitical consequences of reintroductions. Establishment of programs to monitor suites of species interactions and their consequences for biodiversity and ecosystem health will be a significant challenge. Secure fencing would be a major economic cost, and social challenges will include acceptance of predation as an overriding natural process and the incorporation of pre-Columbian ecological frameworks into conservation strategies.  相似文献   

17.
The world-wide debate on land degradation in arid lands, usually linked to local land use practices, does not reflect methodological advancements in terms of assessments and monitoring that integrate local communities’ knowledge with ecological methods. In this paper, we evaluated the efficacy of three different methods related to herder assessments and monitoring of land degradation; herder knowledge and ecological methods of assessing impacts of livestock grazing along gradients of land use from settlement and joint monitoring of selected marked transects to understand long-term vegetation changes in southwestern Marsabit northern Kenya. The performance of each method was carefully evaluated and interpreted in terms of the indicators used by herders and ecologists. Herder interpretations were then related to ecologists’ empirical analysis of land degradation. The Rendille nomads have a complex understanding of land degradation which combines environmental and livestock productivity indicators, compared to conventional scientific approaches that use plant-based indicators alone. According to the herders, the grazing preference of various livestock species (e.g., grazers versus browsers) influences perceptions of land degradation, suggesting degradation is a relative term. The herders distinguished short-term changes in vegetation cover from long-term changes associated with over-exploitation. They attributed current environmental degradation around pastoral camps, which shift land use between the alternating wet and dry seasons, to year-round grazing. We deduced from long-term observation that herders interpret vegetation changes in terms of rainfall variability, utilitarian values and intensification of land use. Long-term empirical data (23 years) from repeated sampling corroborated herder interpretations. Land degradation was mostly expressed in terms of declines in woody plant species, while spatial and temporal dynamics of herbaceous species reflected the effects of seasonality. The efficacy of the three methods were inferred using explanatory strengths of ecological theory; insightfulness of the methods for describing land degradation and the likelihood of using the methods for promoting local community participation in the implementation of the UN Convention on Combating Desertification (CCD) and the Convention on Biological Diversity (CBD).  相似文献   

18.
巩固与提升生态系统碳汇能力是实现碳达峰、碳中和目标的重要途径之一。生态保护修复对生态系统固碳增汇有着重要影响。2016—2021年,财政部、自然资源部、生态环境部在我国27个省(自治区、直辖市)共支持了三批山水林田湖草生态保护修复工程试点和第一批山水林田湖草沙一体化保护和修复工程,共35个山水工程。通过分析已部署的35个山水工程布局的空间特征和碳汇效益,结合国家重点关注的生态保护修复区域、全国重要生态系统保护和修复重大工程分布、生态系统碳汇重要区域和敏感区域,探索“双碳”目标下山水工程布局优先区及生态保护修复技术策略。研究发现山水工程的碳汇效益具有空间差异性,且山水工程优先区主要依次分布在青藏高原生态屏障区、东北森林带、长江重点生态区(含川滇生态屏障)、南方丘陵山地带、黄河重点生态区(含黄土高原生态屏障)、北方防沙带等的森林、高原草地、荒漠、岩溶地区等区域。基于此,提出未来山水工程在不同区域的技术策略。在森林生态系统为主地区,不仅要提高森林覆盖度、森林质量,还应当加强生物多样性的保护和土壤碳汇能力的提升;在高原草原及冻土地区应加强草地退化和冻土监测,提高草地质量;在西北荒漠化地区加强碳...  相似文献   

19.
The grasslands of the northern Great Plains (NGP) region of North America are considered endangered ecosystems and priority conservation areas yet have great ecological and economic importance. Grasslands in the NGP are no longer self‐regulating adaptive systems. The challenges to these grasslands are widespread and serious (e.g. climate change, invasive species, fragmentation, altered disturbance regimes, and anthropogenic chemical loads). Because the challenges facing the region are dynamic, complex, and persistent, a paradigm shift in how we approach restoration and management of the grasslands in the NGP is imperative. The goal of this article is to highlight four key points for land managers and restoration practitioners to consider when planning management or restoration actions. First, we discuss the appropriateness of using historical fidelity as a restoration or management target because of changing climate, widespread pervasiveness of invasive species, the high level of fragmentation, and altered disturbance regimes. Second, we highlight ecosystem resilience and long‐term population persistence as alternative targets. Third, because the NGP is so heavily impacted with anthropogenic chemical loading, we discuss the risks of ecological traps and extinction debt. Finally, we highlight the importance of using adaptive management and having patience during restoration and management. Consideration of these four points will help management and restoration of grasslands move toward a more successful and sustainable future. Although we specifically focus on the NGP of North America, these same issues and considerations apply to grasslands and many other ecosystems globally.  相似文献   

20.
The potential of Cephalophyllum inaequale was investigated for use in initiating ecosystem restoration in degraded landscapes of Namaqualand, South Africa. Cephalophyllum inaequale, a perennial shrub, is a member of the succulent Mesembryanthemaceae family, typical of the Succulent Karoo Biome and in particular of the Namaqualand area. A bioclimatic envelope was modeled to establish the area in which this species might feasibly be used. The regional bioclimatic potential for C. inaequale proved to be extensive, covering approximately 17,500 km2. An examination of the functional role of C. inaequale showed it to facilitate early seedling survival in this community. A nearest‐neighbor study found no evidence of interspecific competition between C. inaequale and its dominant co‐occurring species, possibly due to vertical stratification of rooting structures. Cephalophyllum inaequale significantly reduced wind speed and soil erosion. Experiments to test the feasibility of propagating, reintroducing, and establishing this species showed that it easily germinates from seed, and transplanted cuttings have a high survival rate. This study demonstrates that C. inaequale has potential for use in initiating the restoration of degraded lands in South Africa .  相似文献   

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