采用遥感手段估算海洋初级生产力研究进展

海洋初级生产力的精确估算对渔业资源评估与管理、海洋生态系统和全球变化等研究具有重要意义.传统的现场测量与估算方法必须依赖于随船采样数据.卫星遥感具有能够获取实时的、大尺度的、动态的海洋环境参数的优点,因此卫星遥感日益成为大尺度海洋初级生产力估算的重要手段.本文从海洋水色传感器的发展历程出发,着重归纳了以叶绿素、浮游植物碳和浮游植物吸收系数为参量的海洋初级生产力的遥感估算方法,并就这3类模型的适应性和复杂程度进行了讨论.在此基础上,进一步分析评价了全球海洋初级生产力遥感估算的研究现状.鉴于当前海洋初级生产力遥感估算研究中存在的问题,今后的研究需要在4个方面进一步加强:1)对全球海洋初级生产力估算进行分区域研究;2)加深对浮游植物吸收系数的研究;3)提高海洋遥感技术水平;4)加强实地测量技术的研究.     

遥感技术支持下的植被生产力与生物量研究进展

目前广泛应用于植被生产力与生物量估算的遥感模型主要有经验模型、物理模型、半经验模型和综合模型 ,它们的应用受到诸如大气、背景、地形、植被覆盖率与结构等因素的影响。遥感技术的迅速发展及其它技术的应用 ,包括热红外、微波和激光遥感仪器以及多角度、高光谱和高分辨率技术等 ,正逐步消除或降低影响因素 ,进一步提高植被生产力与生物量估算的范围和精度     

Satellite-based monitoring of tropical seagrass vegetation: current techniques and future developments

Decline of seagrasses has been documented in many parts of the world. Reduction in water clarity, through increased turbidity and increased nutrient concentrations, is considered to be the primary cause of seagrass loss. Recent studies have indicated the need for new methods that will enable early detection of decline in seagrass extent and productivity, over large areas. In this review of current literature on coastal remote sensing, we examine the ability of remote sensing to serve as an information provider for seagrass monitoring. Remote sensing offers the potential to map the extent of seagrass cover and monitor changes in these with high accuracy for shallow waters. The accuracy of mapping seagrasses in deeper waters is unclear. Recent advances in sensor technology and radiometric transfer modelling have resulted in the ability to map suspended sediment, sea surface temperature and below-surface irradiance. It is therefore potentially possible to monitor the factors that cause the decline in seagrass status. When the latest products in remote sensing are linked to seagrass production models, it may serve as an early-warning system for seagrass decline and ultimately allow a better management of these susceptible ecosystems.     

IMOS National Reference Stations: A Continental-Wide Physical,Chemical and Biological Coastal Observing System

Sustained observations allow for the tracking of change in oceanography and ecosystems, however, these are rare, particularly for the Southern Hemisphere. To address this in part, the Australian Integrated Marine Observing System (IMOS) implemented a network of nine National Reference Stations (NRS). The network builds on one long-term location, where monthly water sampling has been sustained since the 1940s and two others that commenced in the 1950s. In-situ continuously moored sensors and an enhanced monthly water sampling regime now collect more than 50 data streams. Building on sampling for temperature, salinity and nutrients, the network now observes dissolved oxygen, carbon, turbidity, currents, chlorophyll a and both phytoplankton and zooplankton. Additional parameters for studies of ocean acidification and bio-optics are collected at a sub-set of sites and all data is made freely and publically available. Our preliminary results demonstrate increased utility to observe extreme events, such as marine heat waves and coastal flooding; rare events, such as plankton blooms; and have, for the first time, allowed for consistent continental scale sampling and analysis of coastal zooplankton and phytoplankton communities. Independent water sampling allows for cross validation of the deployed sensors for quality control of data that now continuously tracks daily, seasonal and annual variation. The NRS will provide multi-decadal time series, against which more spatially replicated short-term studies can be referenced, models and remote sensing products validated, and improvements made to our understanding of how large-scale, long-term change and variability in the global ocean are affecting Australia''s coastal seas and ecosystems. The NRS network provides an example of how a continental scaled observing systems can be developed to collect observations that integrate across physics, chemistry and biology.     

Review of coral reef ecosystem remote sensing

Coral reef communities face unprecedented pressures at local, regional and global scales as a consequence of climate change and anthropogenic disturbance. Remote sensing, from satellites or aircraft, is possibly the only means to measure the effects of such stresses at appropriately large spatial scales. In the past 30 years, remote sensing of coral reefs has made rapid progress. However, the current technology is still not mature enough to monitor complicated coral reef ecosystems. Compared with foreign research in this field, our work lags far behind. There are still deficiencies in many aspects, such as basic data collection, theoretical research and platform construction. In our nation, it is even unclear how coral reefs disperse and where they may be unhealthy. In this paper, general characteristics of coral reef ecosystems and spectral features of different reef benthos have been summarized, based initially on a review of relevant literature in recent years. Based on the spectral separability of different reef types or benthos, remote sensing can be used to monitor two aspects of coral reefs: (1) Measurement of the ecological properties of reefs. (2) Health assessment of the coral reef ecosystem. In the first part, optical remote sensing methods are widely used to map reef geomorphology and habitats or biotopes. The investigation of geomorphologic zonation has proven to be one of the most successful applications, as different geomorphologic zones are associated with characteristic benthic community structures and occur at spatial scales of tens to hundreds of meters, they are amenable to remote detection by moderate to high resolution sensors. With more and more attention on the ecological problems of coral reefs, a number of studies have used high resolution sensors to map reef communities. The number of classes distinguishable depends on many factors, including the platforms, resolution (spectral, spatial and temporal resolution) and environmental conditions (water depth, water clarity, surface roughness, etc.). Compared with deep water color remote sensing, or terrestrial remote sensing, three techniques for the measurement of reef ecological properties are examined in this paper: (1) Coral reef classification system using remote sensing. (2) Techniques of sea surface correction and water column correction. (3) Techniques of coral reef information extraction from images. In terms of the complexity of coral reef ecosystems, the current techniques still need further improvement or optimization. In the health assessment of coral reef ecosystems, there are two ways to carry out the monitoring using remote sensing: (1) Monitoring the pigment or symbiotic zooxanthellae contents in corals. (2) Measuring the environmental properties of reefs. The first way is theoretically feasible, but difficult to achieve in practice. Currently, most reef health assessments are carried out by measuring environmental parameters, including sea surface temperature, solar radiation, ultraviolet radiation, water color, wind speed and direction, rainfall, ocean acidification, sea level, etc., of which sea surface temperature has been routinely measured by NOAA to monitor coral bleaching. In addition to the contents above, this article puts forward five main prospects for development in the future: (1) Establishment of a coral reef classification system using remote sensing. (2) Satellite launch for monitoring coral reefs. (3) Theoretical and methodological development. (4) Establishment of a spectral database for different reef benthos. (5) Integrated application of multi-source remote sensing data. It is hoped that the information provided here will be a reference for subsequent similar studies.     

Microbial oceanography: paradigms, processes and promise

Life on Earth most likely originated as microorganisms in the sea. Over the past approximately 3.5 billion years, microorganisms have shaped and defined Earth's biosphere and have created conditions that have allowed the evolution of macroorganisms and complex biological communities, including human societies. Recent advances in technology have highlighted the vast and previously unknown genetic information that is contained in extant marine microorganisms, from new protein families to novel metabolic processes. Now there is a unique opportunity, using recent advances in molecular ecology, metagenomics, remote sensing of microorganisms and ecological modelling, to achieve a comprehensive understanding of marine microorganisms and their susceptibility to environmental variability and climate change. Contemporary microbial oceanography is truly a sea of opportunity and excitement.     

Real-time remote monitoring of water quality: a review of current applications, and advancements in sensor, telemetry, and computing technologies

Recent advances in communication and sensor technology have catalyzed progress in remote monitoring capabilities for water quality. As a result, the ability to characterize dynamic hydrologic properties at adequate temporal and spatial scales has greatly improved. These advances have led to improved statistical and mechanistic modeling in monitoring of water quality trends at local, watershed and regional scales for freshwater, estuarine and marine ecosystems. In addition, they have greatly enhanced rapid (e.g., real-time) detection of hydrologic variability, recognized as a critical need for early warning systems and rapid response to harmful algal bloom events. Here, we present some of the landmark developments and technological achievements that led to the advent of real-time remote monitors for hydrologic properties. We conclude that increased use and continuing advancements of real-time remote monitoring (RTRM) and sensing technologies will become a progressively more important tool for evaluating water quality. Recent engineering and deployment of RTRM technologies by federal and state regulatory agencies, industries, and academic laboratories is now permitting rapid detection of, and responses to, environmental threats imposed by increased nutrient loadings, development of hypoxic and anoxic areas, toxicants, and harmful algal bloom outbreaks leading to fish kill events and potential human health impacts.     

无人机在生物多样性遥感监测中的应用现状与展望

近十年, 无人机平台由于其灵活机动、成本低等优势在植被生态调查、资源环境监测、生物多样性保护等领域逐渐兴起。本文从生物多样性遥感监测应用角度首先介绍了无人机分类系统, 为具体工作开展过程中如何选择合适的载体和传感器提供了参考; 继而总结了不同类型无人机的适用性及其可搭载传感器的用途与区别。在此基础上, 针对无人机平台的高精度遥感信息具体应用案例, 就反映生物多样性变化并揭示其驱动机制方面的无人机遥感直接和间接指标的相关研究进展展开阐述。最后, 就目前无人机遥感技术在生物多样性监测领域的应用中存在的限制, 如软硬件结合匹配程度不够、部分设备过于昂贵、法律法规不完善、与传统生物多样性监测手段结合较弱等问题进行探讨。我们认为: 无人机遥感技术可以很好地弥补地面监测与航天、卫星遥感之间的尺度空缺, 更好地将监测点上的结果以准确、可靠的推绎方法扩展到区域尺度供决策分析使用。今后迫切需要进一步加大生物多样性近地面遥感监测项目建设的实施力度, 从整体上提高生物多样性热点区域应对变化的分析预警能力。     

Human ecology and space age technology: Some predictions

Four predictions are made on the future of space age technologies in human and cultural ecology: first, remote sensing systems will generate a need for more fieldwork, not less; second, the services and skills of anthropologists will become essential to the interpretation of satellite data, especially as these relate to areas characterized by non-Western cultural practices; third, training in remote sensing and the use of geographic information systems will become a regular offering for anthropology students; and fourth, since these new systems and methods can be applied retrospectively to the re-analysis of earlier ethnographic works, space age technologies will be with us for some time to come.     

新一代遥感技术助力生态系统生态学研究

随着气候变化和人类活动的加剧, 生态系统正处于剧烈变化中, 生态学家需要从更大的时空尺度去理解生态系统过程和变化规律, 应对全球变化带来的威胁和挑战。传统地面调查方法主要获取的是样方尺度、离散的数据, 难以满足大尺度生态系统研究对数据时空连续性的要求。相比于传统地面调查方法, 遥感技术具有实时获取、重复监测以及多时空尺度的特点, 弥补了传统地面调查方法空间观测尺度有限的缺点。遥感通过分析电磁波信息从而识别地物属性和特征, 反演生态系统组成、能量流动和物质循环过程中的关键要素, 已逐渐成为生态学研究中必不可少的数据来源。近年来, 随着激光雷达、日光诱导叶绿素荧光等新型遥感技术以及无人机、背包等近地面遥感平台的发展, 个人化、定制化的近地面遥感观测逐渐成熟, 新一代遥感技术正在推动遥感信息“二维向三维”的转变, 为传统样地观测与卫星遥感之间搭建了尺度推绎桥梁, 这也给生态系统生态学带来了新的机遇, 推动生态系统生态学向多尺度、多过程、多学科、多途径发展。因此, 该文从生态系统生态学角度出发, 重点关注陆地生态系统中生物组分, 并分别从生态系统类型、结构、功能和生物多样性等方面, 结合作者在实际研究工作中的主要成果和该领域国际前沿动态, 阐述遥感技术在生态系统生态学中的研究现状并指出我国生态系统遥感监测领域发展方向及亟待解决的问题。     

遥感用于森林生物多样性监测的进展

随着物种和栖息地的丧失,全球范围的生物多样性保护已经成为迫切的需要。航空航天技术的迅猛发展使遥感成为能提供跨越不同时空尺度监测陆地生态系统生物多样性的重要工具,这方面的研究在欧美等国已经有了小范围的开展,在国内刚刚起步。国外关于生物多样性遥感探测的方法基本有3种:1.利用遥感数据直接对物种或生境制图,进而估算生物多样性;2 .建立遥感数据的光谱反射率与地面观测物种多样性的关系模型;3.与野外调查数据结合直接在遥感数据上进行生物多样性指数制图。研究表明,物种直接制图法只能应用于较小的范围;生境制图的方法,应用广泛,技术相对成熟,研究范围局限于几百公里的范畴,但不能获取生境内部的多样性信息。光谱模型技术目前正处于探索阶段,对于植被复杂、生物多样性高的地域,具有较大的应用潜力。在遥感数据上直接进行生物多样性制图在加拿大已经得到了应用。     

Sensing the sea

The development of the 'ecosystem approach' to the management of marine systems is leading to a requirement for data to be collected with greater frequency and spatial resolution than has been necessary in the past. This is being met both by the analysis of more samples (to better describe variability and temporal change) and by the deployment of instrumented platforms that gather data over long time periods. To meet these requirements in the hostile conditions at sea, a range of sensors based on physical, chemical and biological responses is being developed. These sensors have applications in laboratory analysis of collected samples, during field studies and directly in situ at remote sites for real-time observations of environmental trends. Here, we consider the role that biosensors could have in future marine monitoring programmes.     

The development of new algorithms for remote sensing of snow conditions based on data from the catchment of Øvre Heimdalsvatn and the vicinity

The catchment of Øvre Heimdalsvatn and the surrounding area was established as a site for snow remote sensing algorithm development, calibration and validation in 1997. Information on snow cover and snowmelt are important for understanding the timing and scale of many lake ecosystem processes. Field campaigns combined with data from airborne sensors and spaceborne high-resolution sensors have been used as reference data in experiments over many years. Several satellite sensors have been utilised in the development of new algorithms, including Terra MODIS and Envisat ASAR. The experiments have been motivated by operational prospects for snow hydrology, meteorology and climate monitoring by satellite-based remote sensing techniques. This has resulted in new time-series multi-sensor approaches for monitoring of snow cover area (SCA) and snow surface wetness (SSW). The idea was to analyse, on a daily basis, a time series of optical and radar satellite data in multi-sensor models. The SCA algorithm analyses each optical and synthetic aperture radar (SAR) image individually and combines them into a day product based on a set of confidence functions. The SSW algorithm combines information about the development of the snow surface temperature and the snow grain size (SGS) in a time-series analysis. The snow cover algorithm is being evaluated for application in a global climate monitoring system for snow variables. The successful development of these algorithms has led to operational applications of snow monitoring in Norway and Sweden, as well as enabling the prediction of the spring snowmelt flood and thus the initiation of many lake production processes.     

近20年城市遥感研究现状及其发展趋势

随着城市化进程的不断加速,城市遥感研究已成为地理学、生态学、城市规划学等学科领域主要发展方向之一。城市化使人口与经济增长的同时,也使得城市原有的生态环境状况发生改变,从而引起了一系列城市生态环境问题。城市遥感是一门多学科交叉研究领域,近年来已经取得了一系列显著的研究成果。对近年来城市遥感研究涉及的城市地表温度、边界扩张、不透水表面、景观格局以及生态安全5个方面的理论、研究方法、应用动态以及发展方向进行了较为详细的总结与探讨。主要得出如下结论：（1）数据源从单个遥感数据研究走向多源遥感数据融合发展,多源遥感数据尤其是结合高分辨率数据越来越多的被应用到城市研究的各个领域中;（2）城市遥感的研究目标不断扩展、深化和聚焦;（3）城市遥感研究已开始从二维空间向三维空间拓展;（4）城市遥感涉及的研究对象之间相互作用,相互影响在深入解读城市遥感研究理论意义和潜在挑战的基础上,结合最新研究对本文所涉及的主题进行了补充和完善,为城市典型生态环境问题的解决提供新的思路;今后应按照城市形态与构成、城市关键要素、生态环境响应、生态环境评价以及城市扩展与环境预测的体系结构进行综合分析。     

Pathway engineering via quorum sensing and sRNA riboregulators-interconnected networks and controllers

The advent of genetic engineering has elevated our level of comprehension of cellular processes and functions. A natural progression of these findings is determining not only how these processes function within individual cells but also within a community. Bacterial cells monitor the conditions and microorganisms in their vicinity by producing, releasing and sensing chemical-signaling molecules. When a specific cell-density threshold is reached, a quorum is perceived, gene expression profiles are altered and the community orchestrates activities that are more effective en masse. This communication mechanism, in the language of autoinducers (AI), is referred to as quorum sensing (QS). It has become increasingly evident that while scientists attempt to decipher the intricacies of cellular communication and quorum sensing networks, we must remain conscious of the broader context of how a cell may identify itself in the environment and how this also impacts QS. Importantly, these phenomena span time and length scales by several orders in magnitude. Though the revelation of small RNAs, as both sensing and regulatory elements participating in the quorum sensing cascade, has connected new pieces of the puzzle, it has also added a new tier of uncertainty. The complexity of quorum sensing networks makes resolution of its diverse mechanisms difficult. The ability to design simpler networks with defined, more predictable or even "modular" elements will help elucidate these actions. Because it embraces innovative concepts of biological design accommodating the many length and time scales at play, synthetic biology serves as one of the most promising platforms for describing QS phenomena as well as enabling novel implementation strategies for biotechnological application.     

遥感在生物多样性研究中的应用进展

随着人口的持续增长, 人类经济活动对自然资源的利用强度不断升级以及全球气候变暖, 全球物种正以前所未有的速度丧失, 生物多样性成为了全球关注的热点问题。传统生物多样性研究以地面调查方法为主, 重点关注物种或样地水平, 但无法满足景观尺度、区域尺度以及全球尺度的生物多样性保护和评估需求。遥感作为获取生物多样性信息的另一种手段, 近年来在生物多样性领域发展迅速, 其覆盖广、序列性以及可重复性等特点使之在大尺度生物多样性监测和制图以及评估方面具有极大优势。本文主要通过文献收集整理, 从观测手段、研究尺度、观测对象和生物多样性关注点等方面综述了遥感在生物多样性研究中的应用现状, 重点分析不同遥感平台的技术优势和局限性, 并探讨了未来遥感在生物多样性研究的应用趋势。遥感平台按观测高度可分为近地面遥感、航空遥感和卫星遥感, 能够获取样地-景观-区域-洲际-全球尺度的生物多样性信息。星载平台在生物多样性研究中应用最多, 航空遥感的应用研究偏少主要受飞行成本限制。近地面遥感作为一个新兴平台, 能够直接观测到物种的个体, 获取生物多样性关注的物种和种群信息, 是未来遥感在生物多样性应用中的发展方向。虽然遥感技术在生物多样性研究中的应用存在一定的局限性, 未来随着传感器发展和多源数据融合技术的完善, 遥感能更好地从多个尺度、全方位地服务于生物多样性保护和评估。     

航空航天遥感在物种多样性研究与保护中的应用

人类活动导致全球范围内生物多样性丧失日趋严重。物种多样性是研究最为深入以及最贴近生物多样性管理的层次。物种多样性的研究往往受到多时空尺度生态过程的影响, 传统物种多样性调查方法受到人力物力影响, 局限性大, 物种多样性的研究与管理亟需整合不同来源的数据。遥感技术从传统的光学遥感阶段发展到不同平台、不同维度相结合的多源遥感阶段, 并逐渐进入以高空间分辨率和高光谱为特征、以激光雷达为前沿发展方向的综合遥感阶段。遥感技术因为其监测范围广、能监测人迹罕至地区以及长期可重复等特性, 为研究不同时空尺度的生态学科学问题提供了更新更优的研究手段。本文围绕种群动态、种间关系与群落多样性、功能属性及功能多样性以及生物多样性保护管理等生物多样性研究热点问题, 系统地论述了航空航天遥感技术在物种多样性研究与保护领域的应用, 总结了航空航天遥感技术在研究与物种多样性有关的主要生态学问题中的机遇与挑战。我们认为航空航天遥感技术利用多光谱甚至高光谱与激光技术从空中监测物种多样性, 从不同视角、基于不同光源提供了物种多样性不同侧面的信息, 能够减小地面调查强度, 在大范围和边远地区的物种多样性调查研究中有着至关重要的作用。依据光谱特性的物种判别以及依据激光雷达的三维结构量测将促进生物多样性的研究与管理, 加强遥感学家和生物多样性研究者的沟通交流将有助于促进不同时空尺度的生物多样性与遥感技术的结合。     

A new era in forest restoration monitoring

Monitoring ecological restoration has been historically dependent on traditional inventory methods based on detailed information obtained from field plots. New paradigms are now needed to successfully achieve restoration as a large‐scale, long‐lasting transformative process. Fortunately, advances in technology now allow for unprecedented shifts in the way restoration has been planned, implemented, and monitored. Here, we describe our vision on how the use of new technologies by a new generation of restoration ecologists may revolutionize restoration monitoring in the coming years. The success of the many ambitious restoration programs planned for the coming decade will rely on effective monitoring, which is an essential component of adaptive management and accountability. The development of new remote sensing approaches and their application to a restoration context open new avenues for expanding our capacity to assess restoration performance over unprecedented spatial and temporal scales. A new generation of scientists, which have a background in remote sensing but are getting more and more involved with restoration, will certainly play a key role for making large‐scale restoration monitoring a viable human endeavor in the coming decade—the United Nations' decade on ecosystem restoration.     

Monitoring ecological indicators of rangeland functional integrity and their relation to biodiversity at local to regional scales

Abstract Functional integrity is the intactness of soil and native vegetation patterns and the processes that maintain these patterns. In Australia's rangelands, the integrity of these patterns and processes have been modified by clearing, grazing and fire. Intuitively, biodiversity should be strongly related to functional integrity; that is, landscapes with high functional integrity should maintain biodiversity, and altered, less functional landscapes may lose some biodiversity, defined here as the variety and abundance of the plants, animals and microorganisms of concern. Simple indicators of biodiversity and functional integrity are needed that can be monitored at a range of scales, from fine to coarse. In the present paper, we use examples, primarily from published work on Australia's rangeland, to document that at finer patch and hillslope scales several indicators of landscape functional integrity have been identified. These indicators, based on the quantity and quality of vegetation patches and interpatch zones, are related to biodiversity. For example, a decrease in the cover and width (quantity) and condition (quality) of vegetation patches, and an increase in bare soil (quantity of interpatch) near cattle watering points in a paddock are significantly related to declines in plant and grasshopper diversity. These vegetation patch‐cover and bare‐soil indicators have been monitored traditionally by field‐based methods, but new high‐resolution, remote‐sensing imagery can be used in specific rangeland areas for this fine‐scale monitoring. At intermediate paddock and small watershed scales, indicators that can be derived from medium‐resolution remote‐sensing are also needed for efficient monitoring of rangeland condition (i.e. functional integrity) and biodiversity. For example, 30–100‐m‐pixel Landsat imagery has been used to assess the condition of rangelands along grazing gradients extending from watering‐points. The variety and abundance of key taxa have been related to these gradients (the Biograze project). At still larger region and catchment scales, indicators of rangeland functional integrity can also be monitored by coarse‐resolution remote‐sensing and related to biodiversity. For example, the extent and greenness (condition) of different regional landscapes have been monitored with 1‐km‐pixel satellite imagery. This regional information becomes more valuable when it indicates differences as a result of land management. Finally, we discuss potential future developments that could improve proposed indicators of landscape functional integrity and biodiversity, thereby improving our ability to monitor rangelands effectively.     

Microbial fuel cells: novel microbial physiologies and engineering approaches

The possibility of generating electricity with microbial fuel cells has been recognized for some time, but practical applications have been slow to develop. The recent development of a microbial fuel cell that can harvest electricity from the organic matter stored in marine sediments has demonstrated the feasibility of producing useful amounts of electricity in remote environments. Further study of these systems has led to the discovery of microorganisms that conserve energy to support their growth by completely oxidizing organic compounds to carbon dioxide with direct electron transfer to electrodes. This suggests that self-sustaining microbial fuel cells that can effectively convert a diverse range of waste organic matter or renewable biomass to electricity are feasible. Significant progress has recently been made to increase the power output of systems designed to convert organic wastes to electricity, but substantial additional optimization will be required for large-scale electricity production.