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1.
蒋高明 《植物学通报》2003,20(3):373-382
生态系统退化与人口的增加及人类的活动有直接的关系。长期以来人类对自然生态系统的掠夺性利用造成了各类生态系统的退化,即人为原因是主要的,而自然原因是次要的。在退化生态系统的治理方面,关键要减少自然生态系统恢复演替中人为的压力,而大面积的土地可借助自然力恢复,恢复后的土地可发展成自然保护区,并开展生态旅游等非直接破坏性的活动。应充分考虑到社区的发展问题,解决人的生存出路并提高他们的生活质量,从而在根本上缓解对自然生态系统的压力。本文提出了“以地养地”并借助自然力恢复退化生态系统的模式,利用各种具体例子阐明了我们的观点。最后指出了中国古代先哲关于人与自然的关系原理至今在退化生态系统的恢复中仍然有着现实的指导意义。  相似文献   

2.
滇中几种人工林生态系统恢复效应研究   总被引:5,自引:2,他引:5  
对滇中几种典型人工林生态系统恢复效应研究表明,由不同树种构成的人工林生态系统植物多样性、森林水文、地表土壤侵蚀控制、土壤改良和森林结构的恢复具有显著差异.用乡土树种造林能促进植物多样性.生态恢复变量间具有某种相关关系.草本植物盖度、群落均匀度、Shannon-Wiener指数、土壤有效钾、土壤容重、草本植物生物量、乔木材积、全钾、土壤侵蚀、土壤Si/V、枯落物凋落量、非毛管孔隙、穿透降雨是生态恢复主导效应变量.植物多样性的恢复处于生态恢复的中心位置.并用平均恢复距离指数及恢复距离树对几种生态系统恢复程度进行了评价。  相似文献   

3.
人工草地在退化草地恢复中的作用及其研究现状   总被引:20,自引:0,他引:20  
分析了草地类型生态系统退化的现状、原因及其恢复途径,提出人工草地的建立是恢复退化天然草地的有效途径;综述了人工草地的研究进展。提出高效型人工草地的建立是缓解草原压力、促进牧区可持续发展的良策;从高效角度出发。种植饲用玉米可以作为建立人工草地的一个有益尝试.  相似文献   

4.
The sustainability of ecosystem productivity and rules governing ecosystem development are important topics of scientific research. The emergy approach is an effective method for investigating these topics, especially when used to evaluate systems that have developed under the same environmental conditions, such as climate and soil. In this paper, emergy differences between terrestrial ecosystems were studied in Guyuan County, a region representative of the agro-pastoral ecotone in Hebei Province, China. A combination of field tests and a questionnaire survey were carried out between June and August 2015. The ecosystems studied included natural grassland, artificial grassland, field crops and commercial crops. These four ecosystems were further subdivided into a total of ten ecosystems. Natural grassland was divided into free-grazing and mowed ecosystems; artificial grassland consisted of oat, Chinese leymus and corn silage; field crops included naked oats, flax and wheat; and commercial crops consisted of cabbage and potatoes. The results showed that the rain input of 4.78 × 1014 seJ/ha/yr constituted the highest renewable natural resource emergy and that the purchased emergy inputs of the ten ecosystems ranged from 3.53 to 147.67 × 1014 seJ/ha/yr. Natural resource emergy input was the basic power to maintain the ecosystem, and purchased emergy input was the direct cause of the development of the ecosystems. Groundwater was the most important non-renewable purchased energy for the production of economic crops. The emergy investment ratios (EIR) for potatoes (27.81) and cabbage (19.03) were higher than those of the other ecosystems, but mowed and artificial Chinese leymus grassland had the higher emergy self-sufficiency rates (ESR). Natural grassland, artificial Chinese leymus grassland and traditional grain crops had a low environmental load and high sustainability, whereas potatoes and cabbage had a high environmental load and low sustainability. Overall, rain-fed artificial grassland has a high development potential from the perspective of environment and productivity.  相似文献   

5.
Thirty-two 10 × 10 m2 quadrats were set up in four mangrove communities for the study of the niches of nine plants with horizontal and vertical resource sequences in Dawei Bay, Qi’ao Island, Zhuhai City. Generally, species diversities of natural mangroves were higher than those of plantations. The diversities decreased along sequence of substrate layer, shrub layer and tree layer in natural mangroves; and were highest on the shrub layer in plantations. At the horizontal resource sequence, the niche breadth varied 0.132–0.896 (B(sw)) and 0.120–0.693 (B(L)). The niche breadth of Acanthus ilicifolius and Aegiceras corniculatum were the highest and that of Spartina alterniflora was the lowest. At the vertical resource sequence, the niche breadth varied 0–0.400 (B(sw)) and 0.333–0.747 (B(L)). All the niche breadth values were the lowest except those of A. ilicifolius and A. corniculatum. The niche similarity of the populations varied 0–0.746 and 0–1.000 at the horizontal and vertical resource sequences, respectively. A. ilicifolius and A. corniculatum had niche overlap with all plants at the horizontal resource sequence, while the introduced Sonneratia caseolaris and Sonneratiaapetala had no such overlapping between six and five plants in the community, respectively. At the vertical resource sequence, A. ilicifolius and A. corniculatum had niche overlapping with all the populations. The more niche overlapping existed among the other populations. The results indicated that, currently, the mangrove plantation in Qi’ao Island had a simplex structure and composition of species. The status of plant populations’ niche was determined by the species selected and structure of afforestation. It is suggested to create forest gaps artificially and introduce Kandelia obovata saplings to reverse its current status of lower niche breadth, facilitate natural regeneration and spreading of A. corniculatum and A. ilicifolius, and accelerate the restoration process of natural mangrove. Simultaneously, the species matching and planting methods of mix stands should be emphasized in the future.  相似文献   

6.
As the largest carbon pool of the terrestrial ecosystem, forest plays a key role in sequestrating and reserving greenhouse gases. With the method of replacing space with time, the typical restoration ecosystems of herb (dominated by Deyeuxia scabrescens, P1), shrub (dominated by Salix paraqplesia, P2), broadleaf (dominated by Betula platyphylla, P3), mixed forest (dominated by Betula spp. and Abies faxoniana, P4), and climax (dominated by Abies faxoniana, P5) were selected to quantify the carbon stock and allocation in the subalpine coniferous forest in Western Sichuan (SCFS). The results indicated that the soil organism carbon (SOC) stock decreased with the depth of soil layer, and the SOC per layer and the total SOC increased largely with the vegetation restoration. The contribution of SOC to the carbon stock of ecosystems decreased with the vegetation restoration from 89.45% to 27.06%, while the quantity was from 94.00 to 223.00 t C hm?2. The carbon stock in ground cover increased with the vegetation restoration, and its contribution to the carbon stock of ecosystems was similar (3–4% of the total). Following the vegetation restoration, the plant carbon stock multiplied and reached to 430.86 ± 49.49 t C hm?2 at the climax phase. During the restoration, the carbon stock of different layers increased, and the contribution of belowground to the carbon stock of ecosystems decreased sharply. The carbon stock on ecosystem scale of the climax phase was 5.89 times that of the herb phase. Our results highlighted that the vegetation restoration in SCFS was a large carbon sink.  相似文献   

7.
Questions: What factors limit vegetation restoration of secondary bare saline‐alkaline patches (BSAP) in the Songnen grassland of northeast China? Is there any adaptive approach to promote revegetation in the shortest time possible and at a low cost? Location: Northeast China. Methods: Considering the climate, soil saline‐alkalization and available seed sources, a new approach was adopted to restore vegetation in BSAP, which were formed by the degradation of typical Leymus chinensis grasslands owing to long‐term overgrazing. The experimental treatments included no treatment (CK), fencing (F), fencing+inserting cornstalks (FS), fencing+inserting cornstalks+sowing L. chinensis (FSL) and fencing+inserting cornstalks+sowing Puccinellia chinampoensis (FSP). The assumptions behind inserting cornstalks were not only that they would create safe sites for initial revegetation but also that they would enhance seed input by trapping and containing the seeds from seed movement on the BSAP surface. Results: Seed bank shortage was an important factor limiting initial revegetation in BSAP; seed movement on the BSAP surface could provide the necessary seed source if it were contained by effective measures. Vegetation at the sites FS, FSL and FSP was restored well in terms of the above‐ground biomass and coverage. Inserted cornstalks acted as safe sites that enhanced the plant survival rate in BSAP; they also enhanced the ability to contain seed movement, thus providing a seed source for initial revegetation. Along with initial revegetation, tussocks around cornstalks can provide better safe sites, which in turn can accelerate subsequent vegetation restoration in BSAP. Conclusions: The approach entails the strategic use of diverse seed sources and the construction of safe sites with agricultural byproducts (cornstalks); therefore, it is a low‐cost method and can be used on a widespread scale. The results provide vigorous support in favor of vegetation restoration in BSAP and severely degraded grasslands in the region. In practice, this approach can be used in degraded ecosystems with compacted soil surfaces (including arid and salt‐affected soils) to promote revegetation in various regions.  相似文献   

8.
辽宁省及其沿海区域生态足迹的动态变化   总被引:3,自引:0,他引:3  
利用生态足迹分析法方法计算了辽宁省及其沿海6市(葫芦岛、锦州、盘锦、营口、大连和丹东)2003-2005年的生态足迹,分析了生态足迹的变化规律及变化原因,并评价了该区域可持续发展状况.结果表明:2003-2005年辽宁省及其沿海6市的生态足迹均超过了其生态承载力,全省人均生态赤字有逐年增加的趋势;沿海6市中人均生态赤字最高的城市为盘锦市,然后依次为锦州市、葫芦岛市、营口市、丹东市和大连市.生态足迹供需结构表明,辽宁省及沿海生6市生态足迹需求主要以化石能源地为主,但均有较高的水域类生态盈余.3年间万元GDP生态足迹总体呈下降趋势,表明辽宁省及其沿海6市的资源利用率不断提高.最后提出了减少区域生态赤字的对策.  相似文献   

9.
Resilience against sudden changes in the environment is a very desirable trait in plants used for ecosystem restoration. Mediterranean-like vegetation exhibits particularly strong fire resilience. There are two main functional groups of fire-prone species among Mediterranean-like vegetation: seeders and resprouters. Our aims were to describe how the theory of succession after fire relates to rehabilitation and to use this knowledge to improve the results of rehabilitation attempts in Mediterranean-like ecosystems. Eight post-fire (PF) sites, 14 post-rehabilitated (PR) quarry sites and two woodland sites were sampled. Detrended Canonical Correspondence Analysis (DCCA) showed that PF and PR successions were quite different. Both displayed an increasing abundance of resprouters over time, but seeder density increased throughout PR succession and decreased during PF succession. Nine species were common to both successions in all studied stages. The results showed that until 15-21 years of succession, the post-rehabilitation sites had not become as resilient to fires as sites populated by indigenous vegetation due to the lack of a seeder seed bank. However, after 21 years of PR succession, the exponentially increasing seeder population may allow for seed bank formation and thus eventually improve the fire resilience of the site.  相似文献   

10.
Restoration is increasingly the focus of ecosystem management. Few conceptual models exist for predicting the consequences of restoration, especially those that predict the stages of recovery following restoration. Existing models focus either on defining endpoints for recovery or on defining ecosystem processes, but often do not identify barriers to recovery or potential negative effects of restoration. We describe a conceptual model that identifies the outcomes of the recovery pathways following flow restoration in rivers: the Recovery Cascade Model. The model identifies six general aspects of recovery following restoration: physical ecosystem change; creation of, or improvement in habitat condition; reconnection of the restored area to adjacent ecosystems; recolonization of the restored area; resumption of ecological processes; re-establishment of biotic interactions and reproduction by colonists in the restored area. These aspects may occur in sequence, such that recovery is blocked by a single barrier. The model accommodates feedback loops and includes strong connections between physical processes and ecosystem processes, but also identifies factors that are important in achieving endpoints such as potential barriers to further recovery. Identification of barriers to recovery enables improved planning to maximise the positive effects of restoration. By focussing on outcomes, the model provides a planning tool for managers that can be adapted for different ecosystems and restoration methods and which can be used to identify the amenities that an ecosystem will deliver at different stages of recovery. Ecosystem recovery is as much about overcoming barriers as it is about restorative actions.  相似文献   

11.
Mycorrhizal inoculation can enhance outcomes of ecological restoration, but the benefits may be context-dependent. Here, we performed a meta-analysis of field studies to elucidate conditions in which adding mycorrhizal fungi enhances restoration success. We found inoculation increased plant biomass by an average effect size of 1.7 in 70 independent comparisons from 26 field-based studies, with the largest increases to N-fixing woody plants, C4-grasses and plants growing in soils with low plant-available P. Growth responses to inoculation increased with time for the first 3 yr after inoculation, especially for N-fixing woody plants and plants growing in severely altered soils. We found that mycorrhizal inoculation increased species richness of restored plant communities by 30%, promoted establishment of target species, and enhanced similarity of restored to reference communities. We conclude that the addition of mycorrhizal fungi to restoration sites can facilitate rapid establishment of vegetation cover, and restoration of diverse plant communities more akin to reference sites.  相似文献   

12.
南中国海地区主要生态系统的退化现状与保育对策   总被引:1,自引:2,他引:1  
兰竹虹  陈桂珠 《应用生态学报》2006,17(10):1978-1982
南中国海是一个具有重要全球生物多样性意义的地区.由于长期不合理的开发利用,该区域生态系统显著退化,生物多样性严重丧失.南中国海沿岸各国红树林的年均损失率为0.5%~3.5%,海草床有20%~50%遭到破坏,珊瑚礁中有82%呈退化趋势.在对上述生态系统的利用现状、退化原因以及环境问题的跨境影响进行分析的基础上,提出了有效保护和管理南中国海的对策和建议,以期在双边或区域的层面上共同协作,采取适当措施扭转南中国海地区的生态系统退化趋势.  相似文献   

13.
Artificial habitats in marine ecosystems are employed on a limited basis to restore degraded natural habitats and fisheries, and more extensively for a broader variety of purposes including biological conservation and enhancement as well as social and economic development. Included in the aims of human-made habitats classified as artificial reefs are: Aquaculture/marine ranching; promotion of biodiversity; mitigation of environmental damage; enhancement of recreational scuba diving; eco-tourism development; expansion of recreational fishing; artisanal and commercial fisheries production; protection of benthic habitats against illegal trawling; and research. Structures often are fabricated according to anticipated physical influences or life history requirements of individual species. For example, many of the world’s largest reefs have been deployed as part of a national fisheries program in Japan, where large steel and concrete frameworks have been carefully designed to withstand strong ocean currents. In addition, the differing ecological needs of porgy and sea bass for shelter guided the design of the Box Reef in Korea as a device to enhance productivity of marine ranching. The effect of these and other structures on fisheries catch is positive. But caution must be exercised to avoid using reefs simply as fishing devices to heavily exploit species attracted to them. No worldwide database for artificial habitats exists.The challenge to any ecological restoration effort is to define the condition or possibly even the historic baseline to which the system will be restored; in other words, to answer the question: “Restoration to what?” Examples of aquatic ecosystem restoration from Hong Kong (fisheries), the Pacific Ocean (kelp beds), Chesapeake Bay (oysters) and the Atlantic Ocean (coral reefs) are discussed. The degree to which these four situations consider or can approach a baseline is indicated and compared (e.g., four plants per 100 m2 are proposed in one project). Measurement of performance is a key factor in restoration planning. These situations also are considered for the ecosystem and fishery contexts in which they are conducted. All use ecological data as a basis for physical design of restoration structures. The use of experimental, pilot and modeling practices is indicated.A context for the young field of marine restoration is provided by reviewing major factors in ecosystem degradation, such as high stress on 70% of commercially valuable fishes worldwide. Examples of habitat disruption include an extensive hypoxic/anoxic zone in the Gulf of Mexico and nutrient and contaminant burdens in the North Sea. Principles of ecological restoration are summarized, from planning through to evaluation. Alternate approaches to facilitate ecological recovery include land-use and ecosystem management and determining levels of human population, consumption and pollution.  相似文献   

14.
To investigate the applicability of ecological engineering to pollution problems prevalent in present-day Central and Eastern Europe, a SCOPE-UNEP sponsored workshop was held in Estonia in November 1995. The workshop was undertaken specifically to obtain information from and to train planners, managers and scientists in the region. These ‘countries in transition' face, in many respects, unique environmental problems as a result of their recent domination by a centralized planning government system. Twenty workshop findings that resulted from workshop presentations and subsequent discussion are presented. Six papers published as part of this special issue of Ecological Engineering, and summarized here, deal with the general principles of mineland restoration, acidification effects and mitigation in Poland, reestablishment of riparian buffer strips in Estonia, recovery of forests in the Black Triangle of Czechoslovakia and Poland, restoration after 10 years near the Chernobyl nuclear plant accident in the Ukraine, and studies on remediation of contaminated soils in Belarus.  相似文献   

15.
草原群落退化与恢复演替中的植物个体行为分析   总被引:16,自引:1,他引:16       下载免费PDF全文
定度植物个体小型化是在草原过度放牧条件下草原植物植株地片变短、变窄,节间缩短,以及根条分布浅层化等笥状的集合。小型化个体的生态学属性介于环境饰变与生态型之间,特称之为响应型。个体小型化逆转变过程表现出集体行为,小型化个体具有维持其形状的保守性,变化的阶段性和突变性;小型化的逆过程即正常化过程号常规替时间有关。个体经是过度放牧下群落生产力衰退的重要表现,是对过度放牧的负反馈机制。在草原群落经演替机理  相似文献   

16.
Governance challenges are frequently underestimated in forest landscape restoration. Forest restoration practitioners are generally foresters or ecologists and their focus tends to be limited to the specific restoration interventions themselves, such as removing exotic species, protecting sites for natural regeneration and re-planting indigenous trees. Indeed there are many technical challenges, unknowns in technical aspects of forest landscape restoration and knowledge gaps. However, and even more so when dealing with large scales, additional challenges that fall under the governance umbrella such as tenure, policy measures and institutions have a significant impact on restoration, influencing it either positively or negatively. Conversely, the landscape-scale restoration work itself can influence and shape governance arrangements. This paper attempts to explore this wider relationship between large scale forest restoration − and specifically forest landscape restoration (FLR) − and governance. It is intended to assist and provide guidance to forest landscape restoration practitioners, researchers and policymakers on the consideration and importance of governance, and alternative ways in which the two-way relationship (between governance and FLR) plays out. A framework is proposed to support practitioners, researchers and decision-makers to address governance in forest landscape restoration.  相似文献   

17.
红树林湿地是中国东南沿海的关键生态系统之一。近年来, 我国红树林陆续出现多种害虫种群暴发成灾的现象, 使红树林湿地的可持续利用面临严重挑战。本文归纳了近20年来中国红树林生态系统的主要害虫种类, 危害较严重的有海榄雌瘤斑螟Acrobasis sp., 毛颚小卷蛾Lasiognatha cellifera, 丽绿刺蛾Latoia lepida, 白囊袋蛾Chalioides kondonis, 蜡彩袋蛾Chalia larminati和小袋蛾Acanthopsyche subferalbata等; 对红树林虫害的防控现状进行总结, 目前开展的防控工作主要以生物农药、 昆虫生长调节剂、 昆虫天敌等生物防治方法为主, 结合灯光诱杀等物理防治手段的运用, 对暴发期的害虫种群可以取得较好的控制效果; 并从红树林生态系统健康水平和昆虫群落多样性等方面对害虫种群的成灾原因进行初步探讨; 最终提出以虫害可持续控制为目标的红树林生态系统生境调控策略, 以期为提高红树林湿地虫害管理水平以及促进红树林的可持续发展提供重要的理论参考和科学指导。  相似文献   

18.
19.
Owing to the influence of the Tibeto-Himalayan Highland, the east-and southeastcoastal zone of the Asian continent lacks the subtropical dry belt, which elsewhere in the world separates temperate forest areas from the humid tropics. Thus forest climates with sufficient rainfall cover coastal areas of the Western Pacific from subarctic eastern Siberia to equatorial SE Asia, giving rise to a sequence of five forest formations. The warmtemperate evergreen (lucidophyll) forest formation is peculiar to this region and represents the east-coast counterpart of Mediterranean sclerophyll forest, which develops under the west-coast climate with a different pattern of seasonal rainfall distribution. The characteristics of the five formations and their latitudinal distribution were briefly described as being related to climatic environments. Certain ecosystem properties such as floristic diversity and the rate of organic matter decomposition were found to be very sensitive to thermal gradients, whereas the responses of plant biomass, primary productivity, etc. to changes in thermal climate were less apparent.  相似文献   

20.
There is a need for a consistent forest restoration strategy for the `Black Triangle', Central Europe. In the past 50 years, forests in this area have been heavily affected by industrial pollution. Recently, the amount of pollutants has decreased. This means that effective forest restoration programmes can be started. Forest decline must be seen as an ecological disturbance which cannot be solved by applying technical measures only. An ecosystem approach to forest restoration must be introduced into restoration policy and management. Basic principles and working methods of such an approach are briefly described and proposals are made for forest restoration policy, management and research in the area.  相似文献   

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