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221.
Egon?NoeEmail author Niels?Halberg Jens?Reddersen 《Journal of Agricultural and Environmental Ethics》2005,18(4):383-414
Organic farming is expected to contribute to conserving national biodiversity on farms, especially remnant, old, and undisturbed small biotopes, forests, and permanent grassland. This objective cannot rely on the legislation of organic farming solely, and to succeed, farmers need to understand the goals behind it. A set of indicators with the purpose of facilitating dialogues between expert and farmer on wildlife quality has been developed and tested on eight organic farms. “Weed cover in cereal fields,” was used as an indicator of floral and faunal biodiversity in the cultivated land, and “uncultivated biotope area” on the farm was used as a general measure of wildlife habitats. Functional grouping of herbaceous plants (discriminating between “high conservation value” plant species and “competitive”/“ruderal” species) and low mobility butterflies were used as indicators of conservation value, especially focusing on the few sites left with considerable remnant conservation value. The dialog processes revealed that the organic farmers’ ideas and goals of conservation of wildlife quality were not necessarily the same as for biologists; the farmers expressed very different opinions on the biological rooted idea, that wildlife quality is related to the absence of agricultural impact. However, farmers also stated that the information given by the indicators and especially the dialogue with the biologist had influenced their perception and awareness of wildlife. We conclude that, combined with a dialogue process, using these indicators when mapping wildlife quality could be an important key component of a farm wildlife management advisory tool at farm level. 相似文献
222.
Sabine Wamser Jens DauberKlaus Birkhofer Volkmar Wolters 《Agriculture, ecosystems & environment》2011,144(1):235-240
The colonisation of winter barley fields by spring breeding carabids and its temporal modulation by the amount of potential hibernation sites was studied. Species richness of carabids was lower in landscapes with high length of boundaries and a high amount of non-cropped open habitats during early stages of the beetles’ colonisation of arable fields. Species number of beetles with high dispersal potential responded to this landscape features at coarse spatial scales whereas beetles with low dispersal potential responded to intermediate scales. However, the negative impact of potential hibernation sites on colonisation diminished in later sampling phases. The patterns observed may be explained by both overwintering in arable soils in less complex landscapes and delayed colonisation in more complex landscapes. The seasonal patterns of landscape control suggest a need to account for temporal dynamics in interactions between species or functional groups and landscape properties. A high temporal resolution is needed in studies that focus on ecosystem function and services in agricultural landscapes, as direction of effect (positive/negative) of management on animal communities may change across spatial scales and within short time periods. 相似文献
223.
Jens Havskov Sørensen Alix Rasmussen Thomas Ellermann Erik Lyck 《Atmospheric environment (Oxford, England : 1994)》1998,32(24):101
During the first European Tracer Experiment (ETEX) tracer gas was released from a site in Brittany, France, and subsequently observed over a range of 2000 km. Hourly measurements were taken at the National Environmental Research Institute (NERI) located at Risø, Denmark, using two measurement techniques. At this location, the observed concentration time series shows a double-peak structure occurring between two and three days after the release. By using the Danish Emergency Response Model of the Atmosphere (DERMA), which is developed at the Danish Meteorological Institute (DMI), simulations of the dispersion of the tracer gas have been performed. Using numerical weather-prediction data from the European Centre for Medium-Range Weather Forecast (ECMWF) by DERMA, the arrival time of the tracer is quite well predicted, so also is the duration of the passage of the plume, but the double-peak structure is not reproduced. However, using higher-resolution data from the DMI version of the HIgh Resolution Limited Area Model (DMI-HIRLAM), DERMA reproduces the observed structure very well. The double-peak structure is caused by the influence of a mesoscale anti-cyclonic eddy on the tracer gas plume about one day earlier. 相似文献
224.
Industrial-scale injection of CO2 into saline formations in sedimentary basins will cause large-scale fluid pressurization and migration of native brines, which may affect valuable groundwater resources overlying the deep sequestration aquifers. In this paper, we discuss how such basin-scale hydrogeologic impacts (1) may reduce current storage capacity estimates, and (2) can affect regulation of CO2 storage projects. Our assessment arises from a hypothetical future carbon sequestration scenario in the Illinois Basin, which involves twenty individual CO2 storage projects (sites) in a core injection area most suitable for long-term storage. Each project is assumed to inject five million tonnes of CO2 per year for 50 years. A regional-scale three-dimensional simulation model was developed for the Illinois Basin that captures both the local-scale CO2–brine flow processes and the large-scale groundwater flow patterns in response to CO2 storage. The far-field pressure buildup predicted for this selected sequestration scenario support recent studies in that environmental concerns related to near- and far-field pressure buildup may be a limiting factor on CO2 storage capacity. In other words, estimates of storage capacity, if solely based on the effective pore volume available for safe trapping of CO2, may have to be revised based on assessments of pressure perturbations and their potential impacts on caprock integrity and groundwater resources. Our results suggest that (1) the area that needs to be characterized in a permitting process may comprise a very large region within the basin if reservoir pressurization is considered, and (2) permits cannot be granted on a single-site basis alone because the near- and far-field hydrogeologic response may be affected by interference between individual storage sites. We also discuss some of the challenges in making reliable predictions of large-scale hydrogeologic impacts related to CO2 sequestration projects. 相似文献
225.
Jens Folke 《毒物与环境化学》2013,95(3):201-224
A system of environmental impact assessment of industrial effluents is presented and discussed. Environmental assessment consists of three phases, hazard assessment, risk determination, and societary evaluation. It is regarded an integrated study of natural sciences, i.e. ecochemicology (chemical fate), ecotoxicology (toxical effects), and ecoepidemiology (biological damages); and social sciences, e.g. geography, sociology, and economy. And the outcome should be the basis of political decision making. Hazard assessment may be divided into a subphase of hazard identification from a base set of scientific information on the industrial effluent, and a second subphase of hazard analysis at a more elevated level of scientific information akin to the procedures suggested elsewhere for single chemicals. Methods of hazard assessment are laboratory experiments, e.g. chemical analysis, degradation and bioaccumulation studies, acute and chronic toxicity assessments, physical modelling, etc. Risk determination may then be conducted by extrapolation of the obtained results from laboratory to field, i.e. by risk estimation to the receiving waters, using methods of hydraulic modelling, biological surveillance, etc. Risk‐benefit evaluation is conducted in the society evaluation phase by balancing environmental consequences against the society value of the production. The outcome is determined by the interaction between hazard‐makers (industry), risk‐takers (administrators), guardians (regulators), and assessors (scientists) in risk management, the crank of environmental assessment. 相似文献
226.
David Demeritt Hannah Cloke Florian Pappenberger Jutta Thielen Jens Bartholmes Maria-Helena Ramos 《Environmental Hazards》2013,12(2):115-127
Under the auspices of the World Meteorological Organization, there are a number of international initiatives to promote the development and use of so-called ensemble prediction systems (EPS) for flood forecasting. The campaign to apply these meteorological techniques to flood forecasting raises important questions about how the probabilistic information these systems provide can be used for what in operational terms is typically a binary decision of whether or not to issue a flood warning. To explore these issues, we report on the results of a series of focus group discussions conducted with operational flood forecasters from across Europe on behalf of the European Flood Alert System. Working in small groups to simulate operational conditions, forecasters engaged in a series of carefully designed forecasting exercises using various different combinations of actual data from real events. Focus group data was supplemented by a follow-up questionnaire survey exploring how flood forecasters understand risk, uncertainty, and error. Results suggest that flood forecasters may not instinctively use ensemble predictions in the way that promoters of EPS perhaps think they should. The paper concludes by exploring the implications of these divergent ‘epistemic cultures’ for efforts to apply ensemble prediction techniques developed in the context of weather forecasting to the rather different one of flood forecasting. 相似文献
227.
Alexander D. M. Wilson Stefan Krause Niels J. Dingemanse Jens Krause 《Behavioral ecology and sociobiology》2013,67(1):163-173
In recent years, animal social interactions have received much attention in terms of personality research (e.g. aggressive or cooperative interactions). However, other components of social behaviour such as those describing the intensity, frequency, directedness and individual repeatability of interactions in animal groups have largely been neglected. Network analysis offers a valuable opportunity to characterize individual consistency of traits in labile social groups and therein provide novel insights to personality research in ways previously not possible using traditional techniques. Should individual network positions be consistently different between individuals under changing conditions, they might reflect expressions of an individual's personality. Here, we discuss a conceptual framework for using network analyses to infer the presence of individual differences and present a statistical test based on randomization techniques for testing the consistency of network positions in individuals. The statistical tools presented are useful because if particular individuals consistently occupy key positions in social networks, then this is also likely to have consequences for their fitness as well as for that of others in the population. These consequences may be particularly significant since individual network position has been shown to be important for the transmission of diseases, socially learnt information and genetic material between individuals and populations. 相似文献
228.
Correlation between the seasonal distribution of harbour porpoises and their prey in the Sound,Baltic Sea 总被引:1,自引:1,他引:0
Signe?SveegaardEmail author Heidi?Andreasen Kim?N.?Mouritsen Jens?Peder?Jeppesen Jonas?Teilmann Carl?C.?Kinze 《Marine Biology》2012,159(5):1029-1037
Low densities of harbour porpoises in winter (November–March) and high densities in summer (April–October) were found in the
Sound, connecting the Baltic Sea and Kattegat. Due to their high energy requirements, it is hypothesized that the density
of harbour porpoises is related to local prey abundance. This was tested by examining the stomach content of 53 harbour porpoises
collected between 1987 and 2010 in the Sound (high season, 34 porpoises; low season, 19 porpoises). A total of 1,442 individual
fish specimens from thirteen species were identified. Twelve of these were present in the high–porpoise density season and
seven in the low-density season. The distribution of occurrence and the distribution of number of fish species were different
between seasons, indicating a shift in prey intake between seasons. Furthermore, during the high-density season, the mean
and total prey weight per stomach as well as the prey species diversity was higher. However, no difference was found in the
number of prey species between the two seasons, indicating a higher quality of prey in the high-density season. Atlantic cod
was found to be the main prey species in terms of weight in the high-density season while Atlantic herring and Atlantic cod
were equally important during the low-density season. Prey availability and predictability are suggested as the main drivers
for harbour porpoise distribution, and this could be caused by the formation of frontal zones in spring in the northern part
of the Sound, leading to prey concentrations in predictable areas. 相似文献
229.
Potential banana skins in animal social network analysis 总被引:2,自引:2,他引:0
Social network analysis is an increasingly popular tool for the study of the fine-scale and global social structure of animals.
It has attracted particular attention by those attempting to unravel social structure in fission–fusion populations. It is
clear that the social network approach offers some exciting opportunities for gaining new insights into social systems. However,
some of the practices which are currently being used in the animal social networks literature are at worst questionable and
at best over-enthusiastic. We highlight some of the areas of method, analysis and interpretation in which greater care may
be needed in order to ensure that the biology we extract from our networks is robust. In particular, we suggest that more
attention should be given to whether relational data are representative, the potential effect of observational errors and
the choice and use of statistical tests. The importance of replication and manipulation must not be forgotten, and the interpretation
of results requires care.
This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and
R. James). 相似文献
230.
Jolyon J. Faria John R. G. Dyer Romain O. Clément Iain D. Couzin Natalie Holt Ashley J. W. Ward Dean Waters Jens Krause 《Behavioral ecology and sociobiology》2010,64(8):1211-1218
Collective animal behaviour has attracted much attention recently, but cause-and-effect within interaction sequences has often
been difficult to establish. To tackle this problem, we constructed a robotic fish (‘Robofish’) with which three-spined sticklebacks
(Gasterosteus aculeatus L.) interact. Robofish is a computer-controlled replica stickleback that can be programmed to move around a tank. First,
we demonstrated the functioning of the method: that the sticklebacks interacted with Robofish. We examined two types of interaction:
recruitment and leadership. We found that Robofish could recruit a single fish from a refuge and could initiate a turn in
singletons and in groups of ten, i.e. act as a leader. We also showed that the influence of Robofish diminished after the
first 30 min that fish spent in a new environment. Second, using this method, we investigated the effects of metric and topological
inter-individual distance on the influence that Robofish had on the orientation of fish in a shoal of ten. We found that inter-individual
interactions during this turn were predominantly mediated by topological, rather than metric, distance. Finally, we discussed
the potential of this novel method and the importance of our findings for the study of collective animal behaviour. 相似文献