A New Statistical Dynamic Analysis of Ecosystem Patterns

While phenomenological investigations of ecosystem patterns often fail to reveal underlying dynamic mechanisms, we highlight a universal principle for pattern formation in ecosystems. We consider ecosystems to be typical complex adaptive systems that seek an optimal process to obtain maximized flux under given constraints. An analysis of the optimal process reveals underlying microscopic dynamic mechanisms that induce complex patterns in ecosystems. We emulate ecosystem patterns using a Self-Organization Feature Map: an artificial neural network theoretical model by which evolution processes, structural classifications, and the fractal growth of ecosystem patterns can be simulated. The results help us analyze the formation and dynamics of ecosystem patterns, with attending implications for the classification, protection, and optimization of ecosystems.     

The Great Lakes, an Ecosystem Rehabilitated, But Still Under Threat

Since 1972, the Parties (United States and Canada, 1987) to the Great Lakes Water Quality Agreement have been working collaboratively to achieve the purpose of the Agreement “to restore and maintain the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem”. Billions of dollars and countless person – hours have been expended towards this end, but have the Parties, and their numerous collaborators at the state, provincial, and municipal levels, along with industry and citizen activists achieved meaningful results? This paper will examine the information provided through various monitoring programs and will assess the success of the Parties' programs, and will also discuss the continuing threats to achieving the purpose of the Agreement.     

Time-Consistent Equilibria in Common Access Resource Games with Asymmetric Players Under Partial Cooperation

Given a differential game, if agents have different time preference rates, cooperative (Pareto optimum) solutions obtained by applying Pontryagin’s maximum principle become time inconsistent. We derive a set of dynamic programming equations in continuous time whose solutions are time-consistent equilibria for problems in which agents differ in their utility functions and also in their time preference rates. The solution assumes cooperation between agents at every time. Since coalitions at different times have different time preferences, equilibrium policies are calculated by looking for Markov (subgame perfect) equilibria in a (noncooperative) sequential game. The results are applied to the study of a cake-eating problem describing the management of a common property exhaustible natural resource. The extension of the results to a simple common property renewable natural resource model in infinite horizon is also discussed.     

Policy Characterization of Ecosystem management

This paper provides a comparison of ecosystem management (EM) to the traditional regulatory management approach and outlines the characteristics of EM from a policy perspective, defining the conditions under which this management tool can be successfully implemented. Ecosystem management is a collaborative and integrative tool focused on balancing societal needs, economic growth, and environmental protection to ensure the long-term ecological integrity of a particular ecosystem. The characteristics of this particular tool include: (1) its holistic approach to environmental problems; (2) its integration of values (economic, social, and environmental) through a collaborative, multi-partner, decision making structure; (3) its reliance on science to guide decisions and set boundaries; and (4) its ability to learn from the implementation of decisions (adaptive management). Examples are draw from Environment Canada's various regional ecosystem initiatives.     

准噶尔盆地生态系统优先性评价

生态系统是生物多样性的重要组成部分,更是物种多样性和遗传多样性赖以维持和保存的基础。为了有效地保护准噶尔盆地区域内的生态系统,综合应用生态学理论、植被长期研究成果和地理信息系统技术,总结了准噶尔盆地内生态系统类型,分析了各类生态系统特征和空间分布规律,探索了一种生态系统保护优先性评价方法,以期为区域生态保护建设提供依据...     

Marine Birds as Indicators of Arctic Marine Ecosystem Health: Linking the Northern Ecosystem Initiative to Long-Term Studies

Marine birds are sensitive indicators of the condition of marine ecosystems in the Arctic, partly because they feed at the top of the arctic food chain. The Northern Ecosystem Initiative (NEI) recently supported four separate studies that investigated aspects of Arctic marine bird science which simultaneously addressed goals of the NEI to better understand northern ecosystems and their response to environmental stressors. The projects used both scientific and traditional knowledge to examine the relationship between sea-ice, contaminants, and the ecology of marine birds, and to transfer environmental knowledge to students. Results from these investigations confirm that changes are occurring in Arctic environments, and that these are captured through marine bird research. Collectively these studies provided new data that supported NEI objectives of monitoring the health of the Arctic ecosystem, and contributed to Canada's international obligations for Arctic science.     

Mathematics for Scenarios of Biodiversity and Ecosystem Services

Balancing biodiversity conservation with food security and the preservation of a broader set of ecosystem services is among the greatest challenges of the century. The creation of the International Panel for Biodiversity and Ecosystem Services (IPBES), at the interface between decision support and scientific knowledge, is clearly in line with this ecological-economic perspective. IPBES particularly puts forward the development of model-based scenarios making sense economically and ecologically and promoting sustainability. The present paper provides generic modeling methods and tools to address such challenges. The paper argues that the framework of controlled dynamic systems under uncertainty together with ecoviability metrics are especially well suited. Such a modeling framework indeed makes it possible to simultaneously account for complex dynamics, indirect or indirect drivers, uncertainties along with multiple sustainability objectives. These general ideas are exemplified with scenarios relating to two applied fields: (i) fisheries and marine biodiversity and (ii) land-use and avifauna.     

A Review of the Northern Ecosystem Initiative in Arctic Canada: Facilitating Arctic Ecosystem Research Through Traditional and Novel Approaches

The Canadian Arctic is undergoing considerable social and environmental change. Anthropogenic stressors on this sensitive environment include climate change, contaminants, resource extraction, tourism and increasing human populations. The Northern Ecosystem Initiative (NEI) is a program aimed at supporting the sustainability of northern communities, and at improving our understanding of how northern ecosystems respond to these environmental stressors. A key element of the NEI is to establish partnerships between all levels of government, non-governmental environmental agencies, and northern residents. The NEI is an important source of financial support critical for social and environmental scientists as well as northern residents and their community and regional organizations. Initiated in 1998, the NEI has supported numerous northern scientific and capacity-building projects, and has evaluated the information gained from this work to refine and focus its future support to address key information gaps and northern needs.     

An Integrated Ecosystem Assessment of the Interior Columbia Basin

Driven by the need to replace interim direction, address recent species listings as threatened or endangered under the Endangered Species Act, and break the gridlock of implementing actions, the U.S. Department of Agriculture, Forest Service (FS) and the U.S. Department of the Interior, Bureau of Land Management (BLM), initiated an effort to develop a scientifically-sound, ecosystem-based strategy for lands they administer in the Interior Columbia Basin. The effort included an integrated assessment of 58.3 million ha in seven states describing the Basin's current conditions and risks associated with different management strategies. The assessment provides the foundation for environmental impact statements outlining management direction for 31 million hectares of FS and BLM administered lands. The process produced a framework for ecosystem management, ecosystem component (social, economic, landscape, terrestrial, and aquatic) assessments, and estimates of ecological integrity and socioeconomic resiliency.     

Use of Forest Ecosystem Classification systems in fire management

Forest Ecosystem Classification (FEC) systems have been used in the past mainly for forest management decision-making. FEC systems can also serve an important role for decision-making in other disciplines, such as fire management for both wildfire suppression and prescribed burning operations. FEC systems can provide an important means of identifying potential fuels that may be present on a forest site. This fuel information, in combination with current fire weather conditions, as determined by the Canadian Forest Fire Weather Index (FWI) system, can assist fire managers in determining potential fire behaviour if ignition should occur. FEC systems provide a means of identifying the possible presence of a live understory vegetation component, a fuel layer that has been largely ignored in the past due to a lack of information. Dense understory vegetation can produce a very moist microlimate that can effectively hinder fire spread. The use of FEC systems can help in setting priorities on which wildfires need to be attacked aggressively. For prescribed burning, FEC systems can assist in achieving burn objectives better and more safely.     

Applying Satellite Imagery to Triage Assessment of Ecosystem Health

Considerable evidence documents that certain changes in vegetation and soils result in irreversibly degraded rangeland ecosystems. We used Advanced Very High Resolution Radiometer (AVHRR) imagery to develop calibration patterns of change in the Normalized Difference Vegetation Index (NDVI) over the growing season for selected sites for which we had ground data and historical data characterizing these sites as irreversibly degraded. We used the NDVI curves for these training sites to classify and map the irreversibly degraded rangelands in southern New Mexico. We composited images into four year blocks: 1988–1991, 1989–1992, and 1990–1993. The overlap in pixels classified as irreversibly degraded ranged from 42.6% to 84.3% in year block comparisons. Quantitative data on vegetation composition and cover were collected at 13 sites within a small portion of the study area. Wide coverage reconnaissance of boundaries between vegetation types was also conducted for comparisons with year block maps. The year block 1988–1991 provided the most accurate delineation of degraded areas. The rangelands of southern New Mexico experienced above average precipitation from 1990–1993. The above average precipitation resulted in spatially variable productivity of ephemeral weedy plants on the training sites and degraded rangelands which resulted in much smaller areas classified as irreversibly degraded. We selected imagery for a single year, 1989, which was characterized by the absence of spring annual plant production in order to eliminate the confounding effect of reflectance from annual weeds. That image analysis classified more than 20% of the rangelands as irreversibly degraded because areas with shrub-grass mosaic were included in the degraded classification. The single year image included more than double the area classified as irreversibly degraded by the year blocks. AVHRR imagery can be used to make triage assessments of irreversibly degraded rangeland but such assessment requires understanding productivity patterns and variability across the landscapes of the region and careful selection of the years from which imagery is chosen.     

气候变化下的新疆生态环境脆弱性评价

选取了脆弱性、适应能力作为影响新疆生态环境脆弱性的条件层,进一步筛选出海拔、地质环境、沙尘暴、人口密度、降水量、植被类型、生态保护政策7个因子作为成因指标层,并用专家打分法对每个指标赋予权重。将研究区剖分成195个评价单元格,借助G玛强大的数据管理功能,建立与空间数据和属性数据相互关联的生态环境脆弱性数据库;首次采用模糊数学层次分析法作为新疆生态环境脆弱性等级计算的数学模型,计算出新疆生态环境脆弱性等级,并借助CIS进行成果表达。     

Northern Rivers Ecosystem Initiative: Distribution and Effects of Contaminants

In response to a number of recommendations following the Northern Rivers Basin Studies (NRBS) contaminant program, the Northern Rivers Ecosystem Initiative (NREI) focused considerable attention on assessing contaminants from specific sources including pulp mill effluents, atmospheric transport of mercury and the Alberta oil sands operations. NRBS identified a number of major contaminants of concern including polychlorinated biphenyls, dioxins and furans, mercury and various hydrocarbons. Together, the NRBS and the NREI studies have demonstrated major declines in the levels of dioxins and furans over the last decade as pulp and paper mills have changed their process and treatment strategies in response to new Federal regulations. Polychlorinated biphenyls however, continue to be a concern for the region as their levels have not declined in fish and sediments over the course of these studies. Higher levels in sediments downstream of Grande Prairie and Hinton were identified, but the source of these contaminants remains unknown. Chlorinated pesticides were also investigated, and although toxaphene, DDT and other chlorinated organic pesticides were detected in fish tissue, they were present at very low levels. Studies on the oil sands industry in northern Alberta demonstrated limited impacts on the Athabasca River to date, although studies did identify slight to moderate impacts of natural oil seeps on fish and benthic communities in tributary streams. NREI studies also identified endocrine active compounds in the three pulp and paper mill effluents tested, but endocrine disruptive effects in wild fish were minimal. Municipal sewage effluents also contain endocrine active compounds and it is recommended that monitoring continue around these point sources.     

Ecosystem studies on upper region of Ganga River,India

A multi-disciplinary research programme on the Ganga River Ecosystem was launched by the Government of India in 1983 to collect information on its attributes. Monitoring of the initial 509 km unpolluted and unmonitored region of the river falling in partly mountainous and partly upper plain stretches for two years revealed good water quality. The Song River (a tributary) catchment, a victim of extensive mining activity in the past, was found to add maximum mineral load. The Bhagirathi River was found to carry maximum suspended solid load. Organic pollution was low throughout, occasionally showing seasonal and local peaks. The river exhibited a high oxidative state with pH falling in a slightly alkaline range and nutrient levels being very low.Diatoms formed a major part of the encountered genera of phytoplankton. Zooplankton were mainly represented by protozoans. Saprophytic bacteria underwent large spatial and temporal fluctuations. Coliforms exhibited an increasing trend with downstream river distance. The source of pollution could not be specifically characterized from an FC/FS ratio. Only one sample tested positive for enteric virus. The forms of benthic macroinvertebrates indicated a clean stream environment. It was observed that diversity indices, together with evenness and community comparison, could provide a promising approach to determine the state of the community.Eight heavy metals investigated, Cu, Zn, Fe, Cd, Mn, Pb, Ni and Co, were found to be present in the river water and bed sediments. The prominent mode of metal transport was found to be via the suspended load. The concentration of dissolved metals was found within WHO permissible limits. The heavy metal status of the Ganga River was compared with other rivers of the world. Sorptive properties of sediments were found to be similar to the general sorptive behaviour of the clays. Laboratory studies exhibited reasonable short t ₉₀ values for coliform survival in Ganga water. Faecal streptococcus survived longer.     

银川市城市生态服务功能价值的变化分析

生态系统服务价值的研究是目前生态学研究的热点之一。本文基于生态系统服务功能价值理论,根据银川市土地利用变化的情况,定量估算了其土地生态系统为人类提供服务的经济价值。结果表明,1996—2006年银川市生态系统服务价值变化的总态势是先增后减,生态系统服务功能在城市化过程中受到较大的影响。     

Distribution of Heavy Metals in Surface Sediments from an Antarctic Marine Ecosystem

The concentrations of lead, cadmium, copper,chromium, iron, manganese and zinc in surfacesediments collected from Potter Cove, in the 25de Mayo Island (King George Island), Antarctica, andits drainage basin, were measured by atomic absorptionspectroscopy. The obtained results were use todetermine the areal and vertical distribution of themetals of in the Cove and potential sources of thesemetals to this environment. The geochemical datasuggest that most of the metals found in Potter Coveconstitute a redistribution of autochthonous materialswithin the ecosystem. Therefore, the metalconcentrations can be considered to be present atnatural background levels in surface sediments.     

Patterns of Spatial Autocorrelation in Stream Water Chemistry

Geostatistical models are typically based on symmetric straight-line distance, which fails to represent the spatial configuration, connectivity, directionality, and relative position of sites in a stream network. Freshwater ecologists have explored spatial patterns in stream networks using hydrologic distance measures and new geostatistical methodologies have recently been developed that enable directional hydrologic distance measures to be considered. The purpose of this study was to quantify patterns of spatial correlation in stream water chemistry using three distance measures: straight-line distance, symmetric hydrologic distance, and weighted asymmetric hydrologic distance. We used a dataset collected in Maryland, USA to develop both general linear models and geostatistical models (based on the three distance measures) for acid neutralizing capacity, conductivity, pH, nitrate, sulfate, temperature, dissolved oxygen, and dissolved organic carbon. The spatial AICC methodology allowed us to fit the autocorrelation and covariate parameters simultaneously and to select the model with the most support in the data. We used the universal kriging algorithm to generate geostatistical model predictions. We found that spatial correlation exists in stream chemistry data at a relatively coarse scale and that geostatistical models consistently improved the accuracy of model predictions. More than one distance measure performed well for most chemical response variables, but straight-line distance appears to be the most suitable distance measure for regional geostatistical modeling. It may be necessary to develop new survey designs that more fully capture spatial correlation at a variety of scales to improve the use of weighted asymmetric hydrologic distance measures in regional geostatistical models.     

Evaluating Quality of Life, Economic Vulnerabilities, and Drivers of Ecosystem Change

We examined regional conditions and trends related to quality of life and potential vulnerabilities of these factors to changes in the condition of natural resources in the Mid-Atlantic Region, USA. We selected a variety of variables on economic and socio-demographic conditions that demonstrate links between the condition of natural areas and human concerns and that quantify dependencies on resources. We extracted data from economic and population census databases for counties within the study area and present a subset of results of the cluster analyses used to describe condition and potential risks due to distinct combinations of variables. We found that the same variables used to judge quality of life were often correlated with increasing population and thus were likely to be related to land pressures and risks to natural resources. Within the region, economic dependence on resource-harvesting industries such as forestry and fisheries was low (less than 4% of total earnings at most), however, the potential for natural amenities to attract residents appeared to be growing as the self-employed and otherwise mobile people settled in areas with affordable housing and natural amenities. Suburban residential spread had been occurring in both the close-in and distant suburbs of the region's urban areas and some rural, growth appeared to be driven, in part, by businesses migrating to suburbs. Further work is needed to tease apart causal factors for the trends we observed, but correlations clearly existed in some areas between increasing populations and quality of natural surroundings.     

分光光度法分析中增色、褪色反应标准曲线绘制的一般形式

介绍了在分光光度法分析中，增色反应和褪色反应的标准曲线绘制用朗伯-比耳定律可推导出一般数学表达形式。其中增色反应为Ai=kbCi，使用频率较高；褪色反应为A0-Ai=k′bCi，实际工作中应用较少。     

The Development and Implementation of Indicators of Ecosystem Health in the Great Lakes Basin

This paper describes a process for the selection of a suite of ecosystem health indicators for the Great Lakes, as called for in the Great Lakes Water Quality Agreement. The paper also presents some preliminary data on status and trends in ecosystem components based on those indicators. The indicator selection process was carried out by over 150 scientists and managers from both Canada and the USA, and involved the presentation of the proposed indicators at the State of the Lakes Ecosystem Conferences (SOLECs). An open period for comment followed the conferences where input from scientists involved in Great Lakes programs was received. The suite of indicators will, over time, present information in an understandable format that will allow for more informed management decisions.