Modelling suitable estuarine habitats for Zostera noltii, using Ecological Niche Factor Analysis and Bathymetric LiDAR     

Mireia Valle  Ángel BorjaGuillem Chust  Ibon GalparsoroJoxe Mikel Garmendia 《Estuarine, Coastal and Shelf Science》2011,94(2):144-154

Predicting species distribution and habitat suitability is of considerable use in supporting the implementation of environmental legislation, protection and conservation of marine waters and ecosystem-based management. As other seagrasses, Zostera noltii has declined worldwide, mainly due to human pressures, such as eutrophication and habitat loss. In the case of the Basque Country (northern Spain), the species is present only in 3 out of 12 estuaries. From the literature, it is known that at least 6 of these estuaries were formerly vegetated by this seagrass. Consequently, efforts to monitor and restore (potential) habitats have been enhanced. Therefore, we aim: (i) to determine the main environmental variables explaining Zostera noltii distribution, within the Basque estuaries based upon the Oka estuary; (ii) to model habitat suitability for this species, as a wider applicable management-decision tool for seagrass restoration; and (iii) to assess the applicability and predicted accuracy of the model by using internal and external validation methods. For this purpose, Ecological Niche Factor Analysis (ENFA) has been used to model habitat suitability, based upon topographical variables, obtained from bathymetric Light Detection And Ranging (LiDAR); sediment characteristics variables; and hydrodynamic variables. The results obtained from the ecological factors of the ENFA (Marginality: 1.00; Specialization: 2.59) indicate that the species habitat differs considerably from the mean environmental conditions over the study area; likewise, that the species is restrictive in the selection of the range of conditions within which it dwells. The main environmental variables relating to the species distribution, in order of importance, are: mean grain size; redox potential; intertidal height; sediment sorting; slope of intertidal flat; percentage of gravels; and percentage of organic matter content. The model has a high predicted accuracy (Boyce index: 0.92). Model validation using an independent dataset in the Bidasoa estuary has shown the applicability but also the limitations in extrapolating the habitat suitability model to select suitable transplantation areas in other estuaries with similar morphological and biogeographical characteristics. ENFA-technique, applied with an accurate selection of environmental predictors, could be a promising tool for predicting seagrass habitat suitability which could assist on seagrass conservation and restoration programs worldwide.  相似文献   

Challenges and objectives for geomorphology in U.K. river management     

Andrew Brookes 《地球表面变化过程与地形》1995,20(7):593-610

This paper reviews some of the challenges and objectives in the application of fluvial geomorphology to improved river management in the U.K. It describes the mechanisms by which geomorphology can be applied to solve problems, including the development of design guidance, policy, management approaches, procedures and training. While it is true that geomorphology is being used increasingly, there remain a number of challenges, such as the need to promote a more professional image and to develop appropriate standards. The scientific basis on which decisions relating to the water environment are made needs to be developed further. Perhaps some of the most significant challenges for fluvial geomorphology in U.K. river management during the next decade will concern river and floodplain restoration.  相似文献   

Chemistry and trophic evolution of Lake Lugano in relation to nutrient budget   总被引：1，自引：0，他引：1  

Alberto Barbieri  Rosario Mosello 《Aquatic Sciences - Research Across Boundaries》1992,54(3-4):219-237

Chemical studies performed in the last 50 years on the northern and southern basins of Lago di Lugano are reviewed and discussed in relation to the phosphorus and nitrogen loads from the drainage area.Both basins became eutrophic in the fifties as a consequence of the dense population and industrial activity in the drainage area; the effect of these was aggravated by the meromictic condition of the layer below 100 m in the northern basin.The reduction of phosphorus loads in progress since 1976 has resulted in a significant improvement in the chemical and biological condition of the southern basin and the upper 100 m of water in the northern basin. On the other hand, the balance between dissolved oxygen and reducing substances in the northern basin is shifting toward a decrease of the net oxygen concentration, partly as a consequence of the unusually dry conditions of the last three years.A reduction in phosphorus load down to 18 and 22 t a^–1 in the northern and southern basins respectively is still necessary in order to reduce the lake phosphorus concentration to 30–35 µg O l^–1.  相似文献   

Pelagic food web interactions and hypolimnetic oxygen depletion: Results from experimental enclosures and lakes     

Asit Mazumder  D. J. McQueen  W. D. Taylor  D. R. S. Lean 《Aquatic Sciences - Research Across Boundaries》1990,52(2):144-155

Large lakes enclosures were used to examine the influence of nutrient (P, N) enrichment and planktivorous fish (1 + yellow perch) predation on hypolimnetic oxygen depletion. Results were compared to similar data for lakes with high (Lake St. George) and low (Haynes Lake) abundances of planktivorous fish. In both the unfertilized and fertilized enclosures, fish predation on large cladocerans increased the biomasses of pico- and nanoplankton (0.2–20 µm), phytoplankton (chlorophyll a) and total phosphorus (TP), reduced sedimentation, water clarity, and hypolimnetic oxygen concentrations (AHO). Fertilized enclosures without fish had highest TP and sedimentation rates, but the AHO were low. The high planktivore lake had higher pico- and nanoplankton, higher chlorophyll a, reduced water clarity, and lower AHO than the low planktivore lake. Areal hypolimnetic oxygen depletion (AHOD) rates were strongly related with Secchi depth and plankton size-distribution (r ² = 0.77, and 0.79, respectively), but not as strongly with TP, chlorophyll a, and sedimentation rates (r ² = 0.25, 0.53, and 0.02, respectively). Such observations are useful in forming a generalized hypothesis that lakes with low planktivory and high water clarity have lower oxygen depletion because 1) plankton that are settling are larger and spend less time in the hypolimnetic water column before reaching the sediment, and therefore undergo less decomposition, and 2) the euphotic depth extends into the hypolimnion and production of oxygen can take place.  相似文献   

Research on Ecological Protection and Restoration Measures in Altay Region based on the Coupling Perspective of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System     

LI Yi  LIU Yujie  ZHANG Qiang  ZHU Sufeng  LIU Hao  LIU Shufang 《资源与生态学报(英文版)》2021,12(6):791-800

The adoption of both Nature-based Solutions (NbS) and a system perspective is a hot issue and an area in which there is much room for improvement in ecological protection and restoration. The study takes Altay region as an example, an area located in Xinjiang, China, which is an important ecological corridor of the national key functional area and the core area of the Belt and Road but has a fragile ecological environment and needs much enhancement in ecological protection and restoration. Guided by the concept of “mountains-rivers-forests- farmlands-lakes-grasslands (MRFFLG) system is a life community”, the coupling relationship of the various MRFFLG elements, the main ecological environmental problems and the integrated countermeasures for protection and restoration in Altay region have been analyzed in this study. The study shows that Altay region has a typical meta-ecosystem of mountain, oasis, and desert, and the connections by rivers and lakes make the ecosystem links within the region much closer. The interweaving of resource-environmental-ecological issues of the aquatic ecosystem, degradation of the quality of terrestrial ecosystems such as forests, grasslands and farmlands, the increased ecosystem fragmentation and ecological risks are the major ecological environmental issues in this region. This study takes the improvement of the ecosystem health and function in Altay region as the core goal of regional ecological protection and restoration. First, we establish a zoning governance pattern from the perspective of ecosystem integrity; second, we design governance strategies for different zones with the goal of synergistic improvements in the ecosystem functions; and finally, we clarify the key engineering tasks in different zones from the perspective of ecosystem services. Ecological conservation and restoration of the MRFFLG system is a prime example of the application and development of NbS in China. This paper constructs an analytical framework for identifying regional life communities, diagnosing ecological protection and restoration of zoning problems, and proposing classified solutions for ecological protection tasks for the protection of the MRFFLG system. This research will enrich the theory and technology for the protection and restoration of MRFFLG systems, and provide guidance for the practice of ecological protection and restoration in Altay region.  相似文献   

Practical Exploration of Ecological Restoration and Management of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands System in the Irtysh River Basin in Altay,Xinjiang     

LIU Hanchu  FAN Jie  LIU Baoyin  WANG Li  QIAO Qin 《资源与生态学报(英文版)》2021,12(6):766-776

The Irtysh River Basin refers to a water conservation area and a vital ecological barrier in Xinjiang and also partially in Central Asia. Here, the technical solution for the ecological protection and the restoration of the Mountains-Rivers-Forests-Farmlands-Lakes-Grasslands system (MRFFLGs) pilot project in the Irtysh River Basin is refined, by complying with the core concept, i.e., “mountains, rivers, forests, farmlands, lakes and grasslands are a community of life”. The solution stresses the specific characteristics of ecologically protecting and restoring MRFFLGs in the Irtysh River Basin, which aim to reduce ecological water use, soil erosion, forest and grassland degradation, the ecological destruction of mines, water environment pollution and other issues. With overall protection, system restoration, district policy, and problem orientation as the overarching ideas, 162 sub-items of 44 major items with seven categories have been designed and implemented in the project. In addition, some highlights of the management experience that are worth promoting when the pilot project is being implemented are also summarized (e.g., the use of laws to solve historical problems, scientific argumentation and third-party evaluation, proactive guidance for the engagement of people, modern information technology support, and integration with local sustainable development). Lastly, four policy suggestions are proposed: (1) Building a model of systematic protection and restoration by using basins as the basic geographic unit; (2) Establishing and optimizing key weak links of systems and mechanisms; (3) Focusing on remedying the shortcomings of regional talents, technology and capital; and (4) Promoting the MRFFLGs project to integrate “industry, city, people, and tourism” for carrying out a large-scale system project.  相似文献   

Dilemmas of State-Led Environmental Conservation in China: Environmental Target Enforcement and Public Participation in Minqin County     

KuoRay Mao  Qian Zhang 《社会与自然资源》2018,31(5):615-631

ABSTRACT

This paper examines the acute socioecological crisis in the Minqin region of China’s Gansu province beginning in the 1980s and the multilevel, governmental response to that crisis in the first two decades of the 21st century. Drawing on extensive field research and interviews in the area, supplemented by analysis of available data, the paper presents a detailed case study of the development and implementation of the Shiyang River Watershed Restoration Plan in the period 2007–15. The case illustrates how conflicting policy objectives of the central state-led conservation project shaped patterns of interaction between local government officials, cadres, and farmers in Minqin County as well as ensuing outcomes and challenges in policy implementation. The study finds that top-level declaration of ecological and social issues in the watershed as a national security issue incentivized local government officials and cadres to overlook the Plan’s provision for local consultation, in favor of meeting binding ecological and economic targets. It contributes to scholarship on environmental authoritarianism, illuminating structural factors and institutional constraints that shape local government officials’ and cadres’ behavior in a centrally administered environmental policy context.  相似文献   

科技支撑新疆塔里木河流域生态修复及可持续管理   总被引：1，自引：0，他引：1       下载免费PDF全文

陈亚宁  李卫红  陈亚鹏  朱成刚 《干旱区地理》2018,41(5):901-907

塔里木河流域地处我国西北新疆,面积约102×10⁴ km²,是我国丝绸之路经济带建设的核心区。在过去50 a里,塔里木河流域经历了大规模的水土资源开发,经济社会发展的同时,河道断流,湖泊干涸,沙漠化加剧,生物多样性受损,生态隐忧日益加剧,已威胁塔里木河流域绿洲经济发展和社会稳定,严重影响国家"丝绸之路经济带"建设。荒漠与绿洲生态国家重点实验室针对塔里木河流域的生态环境问题,开展了长期的生态监测与科学研究,基于多年监测调查数据,解析了塔里木河荒漠河岸林植被与地下水的关系,揭示了生态系统退化过程和机理,提出了塔里木河下游合理/胁迫/临界地下水位与流域生态需水量,研发提出的退化生态系统修复重建关键技术得到推广应用;提出的重点生态工程建设方案,被纳入《南疆水利规划》;提出的流域水资源管理建议被国家采纳并实施。科技支撑塔里木河流域生态修复及可持续管理,为丝绸之路经济带生态文明建设提供了重要科学依据和示范样板。  相似文献   

The Impact of Paper Versus Digital Map Technology on Students' Spatial Thinking Skill Acquisition     

Larianne Collins 《The Journal of geography》2018,117(4):137-152

This study investigates whether spatial learning outcomes differ with respect to different instructional media. Spatial thinking skills were tested pre- and postlesson implementation via the spatial thinking ability test as eighth grade students participated in either paper-based or digital map-based instruction. Students' attitudes toward geography, past travel experience, and demographic variables such as gender, were also examined to search for differences in spatial thinking skill development. Results of the study reveal that both paper and digital media aid in developing and improving spatial thinking skill acquisition among students.  相似文献   

Changing Course: Comparing Emerging Watershed Institutions in River Restoration Contexts     

Eileen S. Johnson  Kathleen P. Bell  Jessica E. Leahy 《社会与自然资源》2017,30(6):765-781

How watershed collaborations adapt to changing conditions is an enduring question in collaborative resource management. Our research examined the goals and structure of collaborations within watersheds subject to the same federal and state regulations, but at different restoration states. We employed semistructured interviews, document analysis, and participant observation to complete our qualitative research. Our results suggest that policy stakeholders’ understandings of ecological and social attributes influence watershed goals. Within the impaired system, collaborations invested in shifting public perception to engender support for longer term biophysical restoration. Within the restored watershed, collaborations achieved dramatic biophysical improvements but were challenged in addressing social benefits of restoration. Redefining restoration to incorporate social and ecological systems at the outset provides the opportunity to set benchmarks for measuring success that incorporate social and ecological factors, and to create institutions adept at responding to shifting restoration states.  相似文献