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31.
Nimmermark SA Jacobson LD Schmidt DR Gay SW 《Journal of the Air & Waste Management Association (1995)》2005,55(9):1306-1314
A comparison between predicted and observed odor intensities at 20 neighborhood residences in the vicinity of seven various livestock farms in five different Minnesota counties was made to evaluate the Odor From Feedlots, Setback Estimation Tool (OFFSET) developed by the University of Minnesota. Observations by neighborhood monitors suggest that the OFFSET-predicted separation distances for annoyance-free frequencies of 99, 98, and 97% are large enough. The observations additionally indicate that predicted distances to obtain 94 and 91% annoyance-free frequencies may be large enough for some farms, but for other farms, greater distances may be needed. For two farms in the study, no significant difference between all of the observed and predicted intensities could be found. At four sites, a significant difference was found, and at three of these the difference was considerable. Odor emission rates used in the OFFSET model seem to describe the average emission fairly well for many odor sources, but improvement may be needed for some types of sources. Possible reasons for observations of annoying odor when not predicted include fluctuations in the odor emissions, wind speed fluctuations, topographic variation between sites, sensitivity differences by neighborhood monitors, and background emissions from other sources. 相似文献
32.
Callaghan TV Björn LO Chernov Y Chapin T Christensen TR Huntley B Ims RA Johansson M Jolly D Jonasson S Matveyeva N Panikov N Oechel W Shaver G Schaphoff S Sitch S Zöckler C 《Ambio》2004,33(7):469-473
An assessment of impacts on Arctic terrestrial ecosystems has emphasized geographical variability in responses of species and ecosystems to environmental change. This variability is usually associated with north-south gradients in climate, biodiversity, vegetation zones, and ecosystem structure and function. It is clear, however, that significant east-west variability in environment, ecosystem structure and function, environmental history, and recent climate variability is also important. Some areas have cooled while others have become warmer. Also, east-west differences between geographical barriers of oceans, archipelagos and mountains have contributed significantly in the past to the ability of species and vegetation zones to relocate in response to climate changes, and they have created the isolation necessary for genetic differentiation of populations and biodiversity hot-spots to occur. These barriers will also affect the ability of species to relocate during projected future warming. To include this east-west variability and also to strike a balance between overgeneralization and overspecialization, the ACIA identified four major sub regions based on large-scale differences in weather and climate-shaping factors. Drawing on information, mostly model output that can be related to the four ACIA subregions, it is evident that geographical barriers to species re-location, particularly the distribution of landmasses and separation by seas, will affect the northwards shift in vegetation zones. The geographical constraints--or facilitation--of northward movement of vegetation zones will affect the future storage and release of carbon, and the exchange of energy and water between biosphere and atmosphere. In addition, differences in the ability of vegetation zones to re-locate will affect the biodiversity associated with each zone while the number of species threatened by climate change varies greatly between subregions with a significant hot-spot in Beringia. Overall, the subregional synthesis demonstrates the difficulty of generalizing projections of responses of ecosystem structure and function, species loss, and biospheric feedbacks to the climate system for the whole Arctic region and implies a need for a far greater understanding of the spatial variability in the responses of terrestrial arctic ecosystems to climate change. 相似文献
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SUMMARY Regional business concepts are said to have huge potential to support sustainable development in industrialised countries (e.g. Stransfeld, 1999). However, whereas efforts have been made to implement regional concepts within agriculture and forestry, empirical findings show that regional concepts are only of minor importance to managers within industrial production (Rentz et al., 2000). Considering this situation, the aim of the present article is to explain why regional business concepts have rarely been implemented in the field of industrial production. Therefore, in the course of the present article, a raster for the identification of relevant barriers on a personal, enterprise, inter-firm and macroeconomic level will be developed and applied. Subsequently, suggestions for a set of measures to overcome these barriers to regionalisation will be given. The results have been identified in the framework of a questionnaire to about 30 decision makers of industrial companies within research, a project promoted by the German Ministry of Education and Research. 相似文献
36.
The display of female traits by males is widespread in the animal kingdom. In several species, this phenomenon has been shown to function adaptively as a male mating strategy to deceive sexual rivals (female mimicry). Freshly emerged males of the parasitic wasp Lariophagus distinguendus (Hymenoptera: Pteromalidae) are perceived by other males as if they were females because of a very similar composition of cuticular hydrocarbons which function as a sex pheromone in this species inducing courtship behaviour in males. Within 32 h, however, males deactivate the pheromone and are no longer courted by other males. In this paper, behavioural experiments were performed to test hypotheses on potential costs and benefits associated with the female odour in young males. We did not find any benefits, but demonstrated that young males were significantly more often outrivaled in male-male contests when competing with two older males for a female. Also, young males were significantly more often mounted in homosexual courtship events during these contests. Thus, display of female traits by males is not necessarily beneficial, and in fact, can be disadvantageous. We suggest that these costs have favoured the evolution of the pheromone deactivation mechanism in L. distinguendus males. The function of cuticular hydrocarbons as a female courtship pheromone in L. distinguendus might have evolved secondarily from a primary function relevant for both genders, and the deactivation of the signal in males might have caused a shift of specificity of the chemical signal from the species level to the sex level. 相似文献
37.
Climate-adapted conservation: how to identify robust strategies for the management of reindeer in Hardangervidda National Park (Norway) 总被引:1,自引:0,他引:1
Sven Rannow 《Regional Environmental Change》2013,13(4):813-823
This paper presents an assessment scheme that should help local conservation management in their adaptation to potential effects of climate change. It can be used for the identification of robust adaptation options at site level. The assessment scheme was applied to the management of Europe’s largest population of wild mountain reindeer (Rangifer tarandus tarandus) living in the arctic-alpine plateau of Hardangervidda in south-western Norway. At first, the last four decades (1964–2004) were analysed to identify climate- and non-climate-related driving forces affecting the population. In addition, regional projections of climate change were used to build scenarios for the potential effects on these driving forces until 2050. In the second step, the potential effects of climate change were classified according to the risk they pose to the conservation of reindeer in Hardangervidda. Based on this assessment, no-regret strategies for biodiversity management under changing climate conditions could be identified. 相似文献
38.
Michela Marchi Sven Erik JørgensenEloy Bécares Ilaria CorsiNadia Marchettini Simone Bastianoni 《Ecological modelling》2011,222(16):2992-3001
Using a dynamic model of Lake Chozas developed by Marchi et al. (2011), we tested three hypotheses about recovery of the indigenous community and water quality after radical changes caused by introduction of an invasive allochthonous crayfish, Procambarus clarkii:
- 1.
- Can the lake resist the pressure of an invasive species, like P. clarkii, by adaptation?
- 2.
- Can the ecosystem recover when all the crayfish are removed and low phosphorus concentrations persist in inflow water?
- 3.
- Does the simulated recovery of submerged vegetation occur at a total phosphorus concentration below 100 mg TP m−3, as estimated by Scheffer et al. (1993), Scheffer (1997), Jeppesen et al. (1998) and Zhang et al. (2003)?
- 1.
- Lake Chozas can at least partly resist by adaptation. A combination of possible parameter changes could lead to a significant increase in eco-exergy.
- 2.
- Removal of the phosphorus represented by crayfish (by harvesting) implies complete recovery of the lake and its eco-exergy, albeit not necessarily with the same organisms having the same properties.
- 3.
- The expected hysteresis created by introduction and harvesting of crayfish is observed under the following conditions: phytoplankton dominance at total phosphorus ≥ about 200-250 mg TP m−3 and submerged vegetation returns at total phosphorus < 100 mg TP m−3.
39.
Ecosystem constraints are both ontic and epistemic. They limit activity, and as problems to be solved they drive organization, which is our hypothesis:
The driver of organization is constraint.Solutions proliferate further constraints in an unending spiral of problem (constraint) generation and solution. As constraints proliferate, behavior narrows, and species diversify to compensate (paradox of constraint). Resource enrichment reduces constraints, releases behavior, and reduction of challenges decreases diversity (paradox of enrichment)—high diversity is expressed in low-resource environments and low diversity in high-resource environments. A three-part model of constraints is formulated for non-living systems, and also for goal-directed, problem-solving biota. Mode 1: dynamical means behavior is co-determined by internal states and external inputs. Mode 2: cybernetic employs negative feedback to keep dynamics within goal-oriented operating limits. Mode 3: model-making entails ability to represent (model) physical reality and respond to both phenomenal (modeled) and physical inputs; this property distinguishes living from nonliving systems. Principal sections of the paper elaborate dynamical constraints (three classes), boundary constraints (expressed in edge effects and trophic dynamics), physical constraints (space, time, temperature), chemical constraints (environment fitness, ecological stoichiometry, chemical evolution, limiting factors), coding constraints (environmental vs. genetic coding), network and pathway constraints (connectivity), and natural selection constraints (fitting to the biosphere). Consideration of how the world would look without constraints suggests how fundamental these are in ecosystem emergence, and how the next property in this series, differentiation, would be unmotivated without them. We conclude that constraints as a category are under-studied in ecology, poorly understood in ecological phenomenology, and (our hypothesis) comprise a ubiquitous organizing force in nature. 相似文献
40.
Danika Hill Matthew J. Morr Thibault Stalder Sven Jechalke Eva Top Anne T. Pollar Inna Popova 《环境科学学报(英文版)》2021,33(2):117-130
Although animal manure is applied to agricultural fields for its nutrient value, it may also contain potential contaminants. To determine the variability in such contaminants as well as in valuable nutrients, nine uncomposted manure samples from Idaho dairies collected during 2.5 years were analyzed for macro- and micro-nutrients, hormones, phytoestrogens, antibiotics, veterinary drugs, antibiotic resistance genes, and genetic elements involved in the spread of antibiotic resistance. Total N ranged from 6.8 to 30.7 (C:N of 10 to 21), P from 2.4 to 9.0, and K from 10.2 to 47.7 g/kg manure. Zn (103 – 348 mg/kg) was more abundant than Cu (56 – 127 mg/kg) in all samples. Phytoestrogens were the most prevalent contaminants detected, with concentrations fluctuating over time, reflecting animal diets. This is the first study to document the presence of flunixin, a non-steroidal anti-inflammatory drug, in solid stacked manure from regular dairy operations. Monensin was the most frequently detected antibiotic. Progesterones and sulfonamides were regularly detected. We also investigated the relative abundance of several types of plasmids involved in the spread of antibiotic resistance in clinical settings. Plasmids belonging to the IncI, IncP, and IncQ1 incompatibility groups were found in almost all manure samples. IncQ1 plasmids, class 1 integrons, and sulfonamide resistance genes were the most widespread and abundant genetic element surveyed, emphasizing their potential role in the spread of antibiotic resistance. The benefits associated with amending agricultural soils with dairy manure must be carefully weighed against the potential negative consequences of any manure contaminants. 相似文献