Die Bedeutung der Zeit

The consideration of time in environmental research allows new insights into the fundamentals of environmental research and new pathways for perceiving and answering questions which might arise in environmental research. In order to take this all into account, one must realize that ecological systems have a history and that both the spatial aspects and the chronological expansion of these systems must be taken into consideration. Considering temporalities, rhythms and time scales as well as their interdependencies in environmental research and environmental protection enables us to obtain a better understanding. The significance of relationships and functions in ecological systems can be perceived better as well. The impact of pollutants as well as the outcome of human actions in ecology, and in economics and politics, is consequently mandatory for not only a spatial, but also for the involved temporal scales.     

The integration of land and marine spatial planning

Whilst spatial planning has evolved as a tool to manage the development and use of the terrestrial environment over decades, the development of spatial planning systems for the marine environment are in their infancy. This paper focuses on the integration of land and marine based spatial planning systems. This is informed by a brief overview of the regional development of the lands and seas of Europe which underlie spatial planning systems and by a discussion of respective spatial planning systems in terms of economic sectors, land use, and sea use. The integration of spatial planning systems is then considered, followed by evaluation of relationships between spatial planning, and the wider field of environmental management. This includes consideration of organisational and geographical scales, technical management including legal aspects, policy, strategic planning and time scales of decision-making. The paper identifies the significant factors which must be considered in the integration of marine and terrestrial planning systems over the coming decades.     

Langfristigkeit ökosystemarer Forschung

Time in environmental science continues to be almost neglected. In connection with rising ecological problems long-term research, as is necessary for the evaluation and prediction of environmental conditions, seems to be an exception. Complex ecosystems, e.g. terrestrial and marine systems, however, are characterized by long lasting natural time-scales which must be taken into account by analyzing them. In this context the role of time in ecosystems research becomes important. Therefore, a data base was conceptualized that could take up the main characteristics of ecosystematic analyses. Annual research reports of ecosystem research centers were revised for taking them up into the data base. In this way it is possible to evaluate the pool of data on special aspects, especially on the time parameters of the analyses. One result — besides a partial unequality of the time scales in experiment and reality — is that long-term research in terrestrial ecosystems is very rare. The reasons for this are various, but cannot divert from the need for a greater consideration of longterm observation of the ecosystems. Otherwise the ecosystematic research will not be able to meet their tasks of evaluation and prediction.     

Die Bedeutung der Zeit

Reflecting on time and its nature has a long tradition in such fields as philosophy, economy and the social sciences. In environmental sciences, however, time has not been taken into sufficient consideration to date, although many ecologists are indeed aware of its importance. Because of the importance of time for mankind, nature and the surrounding world, an outline incorporating time is possible and would lead to new insights in environmental sciences. Here, our idea of a balanced or “healthy” ecosystem, or the consequences of our actions such as depletion of the ozon layer, the greenhouse effect or floods are taken into consideration. A reflection on time its a basic requirement for our understanding of environmental science, its tools and our environmental and political actions. A consideration of time in environmental sciences means, among other things, to think of and to act in accordance with time scales and the rhythms of man and nature.     

Stability,vulnerability and persistence of complex ecosystems

The author introduces an operational method to determine the vulnerability of a model ecosystem that is being driven by unpredictable disturbances. This leads naturally to conditions which guarantee the persistence of an ecosystem subject to a perturbing force. It is established that in the world of all possible linear systems, each of which is subjected to a single continual disturbance, systems which are not completely vulnerable are extremely rare. This complements recent results that among randomly connected systems, complexity tends to beget instability rather than stability. It is shown that spatial heterogenity, time lags and nonlinearity reduce the vulnerability of a complex ecosystem to an unpredictable perturbing force.     

Abfallwirtschaftskonzept im Rahmen eines Integrierten Umweltmanagementsystems

Economic regulations on recycling and respective waste disposal legislation will increasingly demand the realization of new waste management concepts. They do not stem from a ministerial goal in itself, but instead offen the enterprizes a chance to develop their own waste disposal strategies with a goal toward the future. In the course of an Intra-company analysis, this waste disposal concept must take the operative organization, the relevant processes and manufacturing techniques, the accumulation of waste in the cost centers as well as the waste disposal and utilization into consideration. Fundamental principles include the environmental regulations applicable to the enterprize in the form of both federal decress and injunctions. An environmental examination report demonstrates the methodical possiblities for stock-taking and makes it possible to identify the measures necessary for improving the operational waste disposal situation. The mandatory data acquisition and a feasible waste monitoring network can be used in the course of environmental management system for making an expert opinion by an independent, reputable environmental verifier.     

Using geospatial business intelligence paradigm to design a multidimensional conceptual model for efficient coastal erosion risk assessment

One of the main challenges in Coastal Erosion Risk Assessment (CERA) is integrating and analysis of conflicting data in various time periods and spatial scales through dissimilar environmental, social, and economic criteria. Currently, Geographical Information Systems (GIS) are widely used in risk assessment despite their drawbacks and limitations as transactional systems for multi-scales, multi-epochs, and multi-themes analysis. Hence, an analytical conceptual framework is proposed in this paper based on geospatial business intelligence paradigm to develop a Spatial Multidimensional Conceptual Model (SMCM) to assess coastal erosion risk. The model is designed based on Spatial On-Line Analytical Processing (SOLAP) platform, on the top of both analytical and transactional paradigms, to allow fast synthesis of cross-tabulated data and easy comparisons over space, scales, epochs, and themes. This objective is achieved through a comprehensive integration of multiple environmental, social, and economic criteria as well as their interactions at various scales. It also takes into account multiple elements at risk such as people, infrastructure, and built environment as different dimensions of analysis. Using this solution allows decision makers to benefit from on-demand, interactive, and comprehensive information in a way that is not possible using GIS alone. The developed model can easily be adapted for any other coastal region through the proposed framework to perform risk assessment. The advantages and drawbacks of the proposed framework are also discussed and new research perspectives are presented.     

Demographic Viability of a Relict Population of the Critically Endangered Plant Borderea chouardii

Abstract:   In addition to human-caused changes in the environment, natural stochasticity may threaten species persistence, and its impact must be taken into account when priorities are established and management plans are designed. Borderea chouardii is a Tertiary relict at risk of extinction that occurs in only one location in the world, where the probability of human disturbance is low. Its persistence, therefore, is mainly linked to its response to natural threats such as stochasticity. Over 8 years I monitored up to 25% of this rupicolous small geophyte. The population had an unbalanced size structure and 90% failure in seed arrival at appropriate microhabitats, which suggests a problem with recruitment. I used matrix models to describe its population dynamics, conducted hand sowings, and performed stochastic simulations to investigate the effect of environmental stochasticity on population trend and viability. I modeled several scenarios to represent a variety of ecological situations, such as population reduction, episodic or persistent disease, and enhancement or decrease of recruitment. Population growth rate (λ) was never significantly different from unity over the study period. The risk of extinction was null over the next five centuries under current conditions. Increase of mortality and decrease of recruitment reduced stochastic population growth rate, but no factor except a persistent increase of 10% mortality resulted in extinction. These results are the consequence of the plant's extremely long life span (over 300 years) and low temporal variability of key vital rates. Even though hand sowing significantly increased the stochastic population growth rate, other approaches may be more important for the persistence of this species. The extremely slow capacity for recovery following disturbances renders habitat preservation essential. In addition, the founding of new populations would reduce the risk associated with habitat destruction.     

Long-Term Ecosystem Dynamics in the Serengeti: Lessons for Conservation

Abstract:  Data from long-term ecological studies further understanding of ecosystem dynamics and can guide evidence-based management. In a quasi-natural experiment we examined long-term monitoring data on different components of the Serengeti-Mara Ecosystem to trace the effects of disturbances and thus to elucidate cause-and-effect connections between them. The long-term data illustrated the role of food limitation in population regulation in mammals, particularly in migratory wildebeest and nonmigratory buffalo. Predation limited populations of smaller resident ungulates and small carnivores. Abiotic events, such as droughts and floods, created disturbances that affected survivorship of ungulates and birds. Such disturbances showed feedbacks between biotic and abiotic realms. Interactions between elephants and their food allowed savanna and grassland communities to co-occur. With increased woodland vegetation, predators' capture of prey increased. Anthropogenic disturbances had direct (hunting) and indirect (transfer of disease to wildlife) effects. Slow and rapid changes and multiple ecosystem states became apparent only over several decades and involved events at different spatial scales. Conservation efforts should accommodate both infrequent and unpredictable events and long-term trends. Management should plan on the time scale of those events and should not aim to maintain the status quo. Systems can be self-regulating through food availability and predator-prey interactions; thus, culling may not be required. Ecosystems can occur in multiple states; thus, there may be no a priori need to maintain one natural state. Finally, conservation efforts outside protected areas must distinguish between natural change and direct human-induced change. Protected areas can act as ecological baselines in which human-induced change is kept to a minimum     

Processes of distribution of pharmaceuticals in surface freshwaters: implications for risk assessment

The global consumption and production of pharmaceuticals is increasing concomitantly with concern regarding their environmental fate and effects. Active pharmaceutical ingredients are mainly released into the aquatic environment through wastewater effluent discharge. Once in the environment, pharmaceuticals can undergo processes of natural attenuation, i.e. dilution, sorption, transformation, depending on physico-chemical properties of the compound, such as water solubility, lipophilicity, vapour pressure, and environmental conditions, such as pH, temperature and ionic strength. A major natural attenuation process is the sorption on dissolved organic matter, colloids, suspended solids and sediments, which in turn control pharmaceuticals distribution, residence time and persistence in aquatic systems. Here we review studies of sorption capacity of natural sorbents to pharmaceuticals. These report on the importance of several environmental and sorbent-specific properties, such as the composition, quality, and amount of the sorbent, and the environmental pH, which determines the speciation of both the sorbent and compound. The importance of accounting for distribution processes on freshwater sorbents for any determination of environmental concentrations of pharmaceuticals is apparent, while the reliability of surrogate standards for measuring dissolved organic matter (DOM) distribution is evaluated in the context of the need for robust environmental risk assessment protocols.     

Interhemispheric comparison of recruitment to intertidal communities: pattern persistence and scales of variation

Recruitment variation can be a major source of fluctuation in populations and communities, making it difficult to generalize results. Determining the scales of variation and whether spatial patterns in the supply of individuals are persistent over time can provide insight into spatial generality and the application of conservation and metacommunity models. We examined these issues using eight-year-long data sets of monthly recruitment of intertidal mussels (Mytilus spp., Perumytilus purpuratus, Semimytilus algosus, Brachidontes granulata) and barnacles (Balanus glandula, Chthamalus dalli, Jehlius cirratus, Notochthamalus scabrosus) at sites spanning > 900 km along the coasts of Oregon-northern California (OR-NCA, 45.47-39.43 degrees N) and central Chile (CC, 29.5-34.65 degrees S). We evaluated four general "null" hypotheses: that despite different phylogenies and great spatial separation of these taxa, their similar life history strategies and environmental settings lead to similar patterns of recruitment (1) between hemispheres, (2) in time, (3) in space, and (4) at larger and smaller spatial scales. Hypothesis 1 was rejected: along the OR-NCA coast, rates of recruitment were between two and three orders of magnitude higher, and patterns of seasonality were generally stronger and more coherent across space and time than along CC. Surprisingly, however, further analysis revealed regularities in both time and space for all species, supporting hypotheses 2 and 3. Temporal decorrelation scales were 1-3 months, and characteristic spatial scales of recruitment were approximately 250 km. Contrary to hypothesis 4, for the ecologically dominant species in both hemispheres, recruitment was remarkably persistent at larger mesoscales (kilometers) but was highly stochastic at smaller microscales (meters). Across species, increased recruitment variation at large scales was positively associated with increased persistence. Our results have several implications. Although the two regions span distinct latitudinal ranges, potential forcing processes behind these patterns include similar large-scale climates and topographically locked hydrographic features, such as upwelling. Further, spatial persistence of the recruitment patterns of most species at the mesoscale supports the view that marine protected areas can be powerful conservation and management tools. Finally, persistent and yet contrasting spatial patterns of recruitment among competing species suggest that recent metacommunity models might provide useful representations of the mechanisms involved in species coexistence.     

Imposed and inherent scales in cellular automata models of habitat

Both observational and modelling studies of the natural environment are characterised by their ‘grain’ and ‘extent’, the smallest and largest scales represented in time and space. These are imposed scales that should be chosen to ensure that the natural scales of the system are captured in the study. A simple cellular automata model of habitat represents only the presence or absence of vegetation, with global and local interactions described by four empirical parameters. Such a model can be formulated as a nonlinear Markov equation for the habitat probability. The equation produces inherent space and time scales that may be considered as transition scales or the scales for recovery from disturbance. However, if the resolution of the model is changed, the empirical parameters must be changed to preserve the properties of the system. Further, changes in the spatial resolution lead to different interpretations of the spatial structure. In particular, as the resolution is reduced, the apparent dominance of one habitat type over the other increases. The model provides an ability to compare both field and model investigations conducted at different resolutions in time and space.     

Urban Fluid Mechanics: Air Circulation and Contaminant Dispersion in Cities

Recently, many urban areas of the world have experienced rapid growth of population and industrial activity raising concerns of environmental deterioration. To meet challenges associated with such rapid urbanization, it has become necessary to implement wise strategies for environmental management and planning, addressing the exclusive demands of urban zones for maintaining environmental sustainability and functioning with minimum disruption. These strategies and related public policy must be based on state-of-the-science tools for environmental forecasting, in particular, on mathematical models that accurately incorporate physical, biological, chemical and geological processes at work on urban scales. Central to such models are the mechanics of environmental fluids (air and water) and their transport and transformation characteristics. Although much progress has been made on understanding environmental flow phenomena, a myriad of issues akin to urban flow, the transport phenomena, air and water quality and health issues (epidemiology) remain to be understood and quantified. We propose to initiate a new focus area – Urban Fluid Mechanics (UFM) – tailored to research on such issues. For optimal societal impact, UFM must delve into fundamental and applied fluid flow problems of immediate utility for the development of urban public policy and environmental regulations. Such efforts often entail the use of `whole' systems approach to environmental studies, requiring careful synthesis between crosscutting areas.In this paper, a few topics in the realm of UFM are presented, the theme being the flow and air quality in urban areas. Topics such as the scales of flow, the atmospheric boundary layer, pollutants and their transport and modeling of flow and air quality are briefly reviewed, discussed and exemplified using case studies. Identification of important flow-related issues, rigorous multidisciplinary approaches to address them and articulation of results in the context of socio-political cause calebre will be the challenges faced by UFM.     

Level of Geographical Subdivision and Its Effects on Assessments of Reserve Coverage: A Review of Regional Studies

Land classes such as vegetation types, ecoregions, or environmental domains can be defined in many ways and at many scales. We set out to quantify the influence of the level of subdivision of land classes on the extent to which the classes are represented in reserves. We examined data on the occurrence of land classes at two or more levels of subdivision in many regional reserve systems. Reserve coverage (the percentage of land classes represented in reserve systems) usually changed as the classes were defined more finely. The extent and general direction of change depended on the reservation threshold or percentage area of land classes needed in the reserve system before they were called "reserved." The results indicate the need to qualify assessments of reserve coverage as dependent on the level of subdivision. They also raise the question of the most appropriate levels of subdivision for such assessments. A definitive answer requires more research on the informativeness of land classes about the biota.     

Relationship between Population Size and Fitness

Abstract:  Long-term effective population size, which determines rates of inbreeding, is correlated with population fitness. Fitness, in turn, influences population persistence. I synthesized data from the literature concerning the effects of population size on population fitness in natural populations of plants to determine how large populations must be to maintain levels of fitness that will provide adequate protection against environmental perturbations that can cause extinction. Integral to this comment on what has been done and what needs to be done, sThe evidence suggests that there is a linear relationship between log population size and population fitness over the range of population sizes examined. More importantly, populations will have to be maintained at sizes of >2000 individuals to maintain population fitness at levels compatible with the conservation goal of long-term persistence. This approach to estimating minimum viable population size provides estimates that are in general agreement with those from numerous other studies and strengthens the argument that conservation efforts should ultimately aim at maintaining populations of several thousand individuals to ensure long-term persistence.     

Sustained dynamic transience in a Lotka-Volterra competition model system for grassland species

Theoretical approaches, such as the Lotka-Volterra framework, enable predictions about long term species coexistence based on stability criteria, but generally assume temporal constancy of system equations and parameters. In real world systems, temporal variability may interfere with the attainment of stable states. Managed grassland ecosystems in Northwestern Europe experience structural periodic fluctuations in environmental conditions: the seasons. In addition, periodic disturbances such as cutting are very common. Here we show, using a Lotka-Volterra system applied to grassland species with empirically derived parameters, that seasonal variability can result in a time dependent equilibrium and redirection of displacement processes.Parameter estimates differed between species and - in most cases - between the seasons. As a result, five of the fifteen tested species combinations had different outcomes of species interactions between seasons. This indicates that systems remain in dynamic transience over the year as the equilibrium changes and the species composition of the system follows the equilibrium without ever attaining it. The non-attainment of the steady state enables coexistence of species even if there is competitive exclusion in one of the seasons. For three of the fifteen species combinations, cutting frequency affected the long-term coexistence patterns. Cutting resets the biomass of competing species and favours during regrowth those species that have a high growth rate, which can alter species coexistence in comparison to a Lotka-Volterra model without cutting. The Lotka-Volterra framework with seasonally changing empirical parameters predicts coexistence as a possible outcome of systems that in component seasons are characterised by exclusion, and vice versa.     

全球化视阈下的生态伦理学研究述论

作为人类文化的重要创新,生态伦理学研究推动了将道德延伸到自然界,通过协调各方利益,规范人类的环境态度和行为,重建人与自然的和谐关系,从而保证人类整体事业的繁荣。生态学所描述的仅仅自然界的自然生态,虽然其基本原理为生态伦理学所吸纳,但后者并非生态加伦理如此简单而已,它的研究对象更为广阔,也更为复杂。人始终是伦理学关怀的主体,其出发点是人,最终的对象也必然是包含人在内的整个自然。在伦理学层面上,人首先是社会性的,其次才是生物性的,在这一方面中国自古以来便形成了良好的生态文化传统。生态伦理的思想若要深深扎根当前所有人的心中,必须首先在全社会形成浓厚的生态文化,使环境保护的理念真正落到实处。以生态伦理为核心的生态文化必将成为人类社会生态文明建设的指南。21世纪继往开来的中国的生态伦理学应该具有清晰的价值定位,不仅需要超越生态学的全自然视角,突出人的社会性,而且需要体现社会主义的制度特征,构建自己的生态伦理话语体系。     

Scale-dependent response diversity of seabirds to prey in the North Sea

Functional response diversity is defined as the diversity of responses to environmental change among species that contribute to the same ecosystem function. Because different ecological processes dominate on different spatial and temporal scales, response diversity is likely to be scale dependent. Using three extensive data sets on seabirds, pelagic fish, and zooplankton, we investigate the strength and diversity in the response of seabirds to prey in the North Sea over three scales of ecological organization. Two-stage analyses were used to partition the variance in the abundance of predators and prey among the different scales of investigation: variation from year to year, variation among habitats, and variation on the local patch scale. On the year-to-year scale, we found a strong and synchronous response of seabirds to the abundance of prey, resulting in low response diversity. Conversely, as different seabird species were found in habitats dominated by different prey species, we found a high diversity in the response of seabirds to prey on the habitat scale. Finally, on the local patch scale, seabirds were organized in multispecies patches. These patches were weakly associated with patches of prey, resulting in a weak response strength and a low response diversity. We suggest that ecological similarities among seabird species resulted in low response diversity on the year-to-year scale. On the habitat scale, we suggest that high response diversity was due to interspecific competition and niche segregation among seabird species. On the local patch scale, we suggest that facilitation with respect to the detection and accessibility of prey patches resulted in overlapping distribution of seabirds but weak associations with prey. The observed scale dependencies in response strength and diversity have implications for how the seabird community will respond to different environmental disturbances.     

Environmental indicators as tools for the management of estuaries—Methodology and case study of the Tejo estuary

The need for a better management of estuaries requires an environmental characterization following a methodology that allows the comparison of distinct estuarine systems and the assessment of their evolution. The peculiar characteristics of estuaries, in particular their intrinsic variability, make this characterization difficult and there is no commonly accepted general methodology available. The approach followed in freshwater ecosystems is generally based on the concept of environmental indicators, but such a concept has not been developed for estuaries. Indeed, a different approach is needed here, due to the spatial heterogeneity and the different time scales associated with the processes that control water quality. This paper presents a proposal for a methodology that starts with observed values and uses a procedure to integrate these values in time and space in order to calculatesignificant values, upon whichnormalized indicators are built which take into account criteria based either on legal, scientific or heuristic concentration limits. A normalization is carried out in two steps: (1) application of a mathematical operator to theignificant values, (2) transformation using the concept ofpenalty curves. This methodology may be complemented with the definition ofquality classes, particularly appealing and useful, as tools to communicate with decision makers and the public in general. Water quality data pertaining to the Tejo estuary are used to test the methodology.