海南儋州海域造礁石珊瑚种类组成及动态变化研究          下载免费PDF全文

廖宝林  肖宝华  覃业曼  谢子强  谢勇琪  朱鸣 《海洋开发与管理》2020,37(7):55-61

文章通过断面法调查分析了儋州海域海花岛沿岸、南华墟沿岸和磷枪石岛沿岸造礁石珊瑚的种类组成与群落分布，结果表明：儋州海域造礁石珊瑚共有12科25属55种，相较于此前的研究增加了10个种，优势种为斯氏角孔珊瑚、澄黄滨珊瑚、柱角孔珊瑚；活造礁石珊瑚覆盖率急剧下降，由2012年的42.92%下降至现在的22.24%，降幅高至48.18%；造礁石珊瑚死亡率高居不下，长期维持在35%左右；初级群落以团块状造礁石珊瑚为优势种的趋势愈发明显，且单一绝对优势种的情况频繁出现，说明该海域造礁石珊瑚群落受到了较为严重的破坏，导致群落退化演替，分析认为这种破坏是由自然因素和人为活动共同造成的。  相似文献   

Assessment of Desert Ecological Assets and Countermeasures for Ecological Compensation     

BAO Yingshuang  CHENG Leilei  LU Qi 《资源与生态学报(英文版)》2019,10(1):56-62

Can deserts be transformed into resources, into assets, and further into cash? It is necessary to scientifically assess desert ecological assets and incorporate them into the national economic accounting system and the current evaluation system for socio-economic development. This study will provide a scientific basis and robust data for establishing a target system that is compatible with both ecological civilization and an associated reward and punishment mechanism, as well as for designing and implementing effective compensation policies for desert ecosystems. This paper first defines desert ecological assets, and then develops a framework for assessing them based on the evaluation of desert ecological resources and desert ecosystem services. This framework paves the foundation for quantitatively assessing desert ecological assets and preparing balance sheets of desert ecological assets. Finally, this paper analyzes current policies relating to desert ecological compensation, discusses how to design compensation policies based on assessment of desert ecological assets, and puts forward suggestions for improving current policies.  相似文献   

Net Horizontal Payments for Ecosystem Services: An Application in the Beijing-Tianjin-Hebei Region of China     

LIN Yongsheng  GUO Zhixin  ZHENG Yaomin  ZHANG Lirong  HUANG Huabing 《资源与生态学报(英文版)》2019,10(1):63-68

Payments for ecosystem services (PES) are one kind of important tool for environmental protection, and have been widely studied by international scholars and conservationists. Based various definitions of PES from recent articles, we have outlined four principles for PES: parity, measurability, additionality and conditionality, and then have used these principles to develop a formula to calculate a standard for PES. Finding a way to use PES to achieve a win-win relationship between economic growth and environmental protection in the Beijing-Tianjin-Hebei Region (BTHR) is a key task for Chinese government. Synergetic development of BTHR has become a national strategy, like The Belt and Road Initiative. This article employed the formula we developed to calculate the net horizontal PES amounts that each provincial government within BTHR should pay. Our findings show that Beijing should have paid 10.44×10⁹ Yuan (0.4% of Beijing’s GRP) and Tianjin 16.56×10⁹ Yuan (0.93% of Tianjin’s GRP) to Hebei in 2016.  相似文献   

Assessing the effects of land cover and future climate conditions on the provision of hydrological services in a medium‐sized watershed of Portugal          下载免费PDF全文

Claudia Carvalho‐Santos  João Pedro Nunes  António T. Monteiro  Lars Hein  João Pradinho Honrado 《水文研究》2016,30(5):720-738

The separated and combined effects of land‐cover scenarios and future climate on the provision of hydrological services were evaluated in Vez watershed, northern Portugal. Soil and Water Assessment Tool was calibrated against daily discharge, sediments and nitrates, with good agreements between model predictions and field observations. Four hypothetical land‐cover scenarios were applied under current climate conditions (eucalyptus/pine, oak, agriculture/vine and low vegetation). A statistical downscaling of four General Circulation Models, bias‐corrected with ground observations, was carried out for 2021–2040 and 2041–2060, using representative concentration pathway 4.5 scenario. Also, the combined effects of future climate conditions were evaluated under eucalyptus/pine and agriculture/vine scenario. Results for land cover revealed that eucalyptus/pine scenario reduced by 7% the annual water quantity and up to 17% in the summer period. Although climate change has only a modest effect on the reduction of the total annual discharge (?7%), the effect on the water levels during summer was more pronounced, between ?15% and ?38%. This study shows that climate change can affect the provision of hydrological services by reducing dry season flows and by increasing flood risks during the wet months. Regarding the combined effects, future climate may reduce the low flows, which can be aggravated with eucalyptus/pine scenario. In turn, peak flows and soil erosion can be offset. Future climate may increase soil erosion and nitrate concentration, which can be aggravated with agriculture scenario. Results moreover emphasize the need to consider both climate and land‐cover impacts in adaptation and land management options at the watershed scale. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Simulation of site-scale water fluxes in desert and natural oasis ecosystems of the arid region in Northwest China     

Mingjuan Xie  Geping Luo  Olaf Hellwich  Amaury Frankl  Wenqiang Zhang  Chunbo Chen  Chen Zhang  Philippe De Maeyer 《水文研究》2021,35(12):e14444

The study of water fluxes is important to better understand hydrological cycles in arid regions. Data-driven machine learning models have been recently applied to water flux simulation. Previous studies have built site-scale simulation models of water fluxes for individual sites separately, requiring a large amount of data from each site and significant computation time. For arid areas, there is no consensus as to the optimal model and variable selection method to simulate water fluxes. Using data from seven flux observation sites in the arid region of Northwest China, this study compared the performance of random forest (RF), support vector machine (SVM), back propagation neural network (BPNN), and multiple linear regression (MLR) models in simulating water fluxes. Additionally, the study investigated inter-annual and seasonal variation in water fluxes and the dominant drivers of this variation at different sites. A universal simulation model for water flux was built using the RF approach and key variables as determined by MLR, incorporating data from all sites. Model performance of the SVM algorithm (R² = 0.25–0.90) was slightly worse than that of the RF algorithm (R² = 0.41–0.91); the BPNN algorithm performed poorly in most cases (R² = 0.15–0.88). Similarly, the MLR results were limited and unreliable (R² = 0.00–0.66). Using the universal RF model, annual water fluxes were found to be much higher than the precipitation received at each site, and natural oases showed higher fluxes than desert ecosystems. Water fluxes were highest during the growing season (May–September) and lowest during the non-growing season (October–April). Furthermore, the dominant drivers of water flux variation were various among different sites, but the normalized difference vegetation index (NDVI), soil moisture and soil temperature were important at most sites. This study provides useful insights for simulating water fluxes in desert and oasis ecosystems, understanding patterns of variation and the underlying mechanisms. Besides, these results can make a contribution as the decision-making basis to the water management in desert and oasis ecosystems.  相似文献   

“全息”地图研究初探     

张兰  郭佳  付飞  安利 《测绘与空间地理信息》2016,(6):96-98

地图产品种类层出不穷,全息地图近年来成为焦点走进人们的视野。本文首先明确了与全息地图相近的三维地图和全景地图的概念;然后,简要阐述了传统的光学全息地图与新兴的全息位置地图的概念、原理以及几种地图产品的差别。在此基础上,分析了两种冠以"全息"二字地图的发展现状,并探讨了它们未来发展的主要方向。  相似文献   

Thrombolite fabrics and origins: Influences of diverse microbial and metazoan processes on Cambrian thrombolite variability in the Great Basin,California and Nevada          下载免费PDF全文

Cara Harwood Theisen  Dawn Y. Sumner 《Sedimentology》2016,63(7):2217-2252

Thrombolites are a common component of carbonate buildups throughout the Phanerozoic. Although they are usually described as microbialites with an internally clotted texture, a wide range of thrombolite textures have been observed and attributed to diverse processes, leading to difficulty interpreting thrombolites as a group. Interpreting thrombolitic textures in terms of ancient ecosystems requires understanding of diverse processes, specifically those due to microbial growth and metazoan activity. Many of these processes are reflected in thrombolites in the Cambrian Carrara, Bonanza King, Highland Peak and Nopah formations, Great Basin, California, USA; they comprise eight thrombolite classes based on variable arrangements and combinations of depositional and diagenetic components. Four thrombolite classes (hemispherical microdigitate, bushy, coalescent columnar and massive fenestrated) contain distinct mesoscale microbial growth structures that can be distinguished from surrounding detrital sediments and diagenetic features. By contrast, mottled thrombolites have mesostructures that dominantly reflect post‐depositional processes, including bioturbation. Mottled thrombolites are not bioturbated stromatolites, but rather formed from disruption of an originally clotted growth structure. Three thrombolite classes (arborescent digitate, amoeboid and massive) contain more cryptic textures. All eight of the thrombolite classes in this study formed in similar Cambrian depositional environments (marine passive margin). Overall, this suite of thrombolites demonstrates that thrombolites are diverse, in both internal fabrics and origin, and that clotted and patchy microbialite fabrics form from a range of processes. The diversity of textures and their origins demonstrate that thrombolites should not be used to interpret a particular ecological, evolutionary or environmental shift without first identifying the microbial growth structure and distinguishing it from other depositional, post‐depositional and diagenetic components. Furthermore, thrombolites are fundamentally different from stromatolites and dendrolites in which the laminae and dendroids reflect a primary growth structure, because clotted textures in thrombolites do not always reflect a primary microbial growth structure.  相似文献   

Cascades of green: A review of ecosystem-based adaptation in urban areas     

《Global Environmental Change》2016

Climate change impacts increase pressure on challenges to sustainability and the developmental needs of cities. Conventional, “hard” adaptation measures are often associated with high costs, inflexibility and conflicting interests related to the dense urban fabric, and ecosystem-based adaptation (EbA) has emerged as a potentially cost-efficient, comprehensive, and multifunctional approach. This paper reviews and systematises research on urban EbA. We propose an analytical framework that draws on theory from ecosystem services, climate change adaptation and sustainability science. It conceptualises EbA in terms of five linked components: ecological structures, ecological functions, adaptation benefits, valuation, and ecosystem management practices.Our review identified 110 articles, reporting on 112 cities, and analysed them using both quantitative statistical and qualitative content analysis. We found that EbA research in an urban context is fragmented due to different disciplinary approaches and concepts. Most articles focus on heat or flooding, and the most studied ecological structures for reducing the risk of such hazards are green space, wetlands, trees and parks. EbA is usually evaluated in bio-geophysical terms and the use of economic or social valuations are rare. While most articles do not mention specific practices for managing ecological structures, those that do imply that urban EbA strategies are increasingly being integrated into institutional structures. Few articles considered issues of equity or stakeholder participation in EbA.We identified the following challenges for future EbA research. First, while the large amount of data generated by isolated case studies contributes to systems knowledge, there is a lack of systems perspectives that position EbA in relation to the wider socio-economic and bio-geophysical context. Second, normative and ethical aspects of EbA require more thought, such as who are the winners and losers, especially in relation to processes that put people at risk from climate-related hazards. Third, there is room for more forward-looking EbA research, including consideration of future scenarios, experimentation in the creation of new ecological structures and the role of EbA in transformative adaptation.  相似文献   

地球观测数据共享的发展和趋势     

李国庆  张红月  张连翀  王媛媛  田传召 《遥感学报》2016,20(5):979-990

地球观测数据共享是地球科学和相关学科科研活动中非常重要的基础性工作,是对地观测信息生命周期中的重要环节。受到由资源提供者、资源消费者和资源加工者组成的社会生态系统发展变化的影响,共享模式经历了无共享、项目共享、部门共享、社会共享等渐进的4个发展阶段,并呈现出区域差异和阶段差异。地球观测数据共享的概念体系包含数据开放、数据共享、数据互联等不同层次的问题,并受到信息技术等使能技术的驱动。其中开放性代表数据在网络中可被访问的状态,共享性是对于数据重复使用的授权和模式,互联性则是强调可共享数据资源在科学含义上的相互理解。而地球观测数据共享的技术体系则包含数据开放技术、数据共享技术和数据出版与引用技术。目前地球观测领域的数据共享正在经历巨大的文化、政策、技术和应用变革,下一代的地球观测数据设施集中体现了数据的共享和协作,并将呈现国际化、多学科化、标准化、设施化、大数据化和公众社会化等新的技术特征,将对相关科学活动产生重大影响。  相似文献   

Identifying geospatial services across heterogeneous taxonomies     

Hao Li  Ling Bian  Teng Wang 《国际地球制图》2016,31(10):1058-1077

Geospatial services with different functions are assembled together to solve complex problems. Different taxonomies are developed to categorize these services into classes. As differences in granularity and semantics exist among these taxonomies, the identification of services across different taxonomies has become a challenge. In this paper, an approach to identify geospatial services across heterogeneous taxonomies is proposed. Using formal concept analysis, existing heterogeneous taxonomies are decomposed into semantic factors and their various combinations. With these semantic factors, a super taxonomy is established to integrate the original heterogeneous taxonomies. Finally, with the super taxonomy as a cross-referencing system, geospatial services with classes in original taxonomies are identifiable across taxonomies. Experiments in service registries and a social media-based spatial-temporal analysis project are presented to illustrate the effectiveness of this approach.  相似文献