Rodent outbreaks affect many farmland areas worldwide and the negative environmental impacts of control campaigns cause intense social tensions. In such conservation conflicts, understanding stakeholders’ viewpoints is critical to promote ecologically sustainable management. We used Q-methodology, a framework standing between qualitative and quantitative social research, to investigate human subjectivity and understand conflicts caused by rodent outbreaks in Spain. We interviewed farmers, conservationists, hunters, and governmental agencies, and identified five main discourses about the origins and consequences of the conflictive situation. Finding sustainable management is impaired by opposing views about causes and consequences of vole outbreaks and their management, which are at the root of the conflict. Social tensions will likely remain until the underlying conflicts between people holding different views are also managed. Decision-making should therefore focus on mitigating underlying conflicts. Using trained independent mediators would help the effective resolution of conservation conflicts caused by rodent outbreaks and their management.
Cathodic adsorptive stripping voltammetry is one of the most sensitive analytical methods for ultratrace analysis. The detection
limit is usually lower than 10−9 mol/L. Most adsorptive stripping procedures have been focused on the one ligand/one analyte approach. In order to reduce
analysis time and sample volume, the possibility of simultaneously determining several metals by cathodic stripping voltammetry
using a mixture of ligands was explored, e.g., by Colombo and van den Berg (1997). Here, we describe a new procedure for quantifying
chromium and copper using 2,2′-bipyridine and 8-hydroxyquinoline (oxine). The effect of various operational parameters such
as buffer type, ligand concentration, potential and time collection were assessed and optimized. Possible interferences by
trace metals and organic matter were also investigated. Applicability for fresh water is illustrated.
Electronic Publication 相似文献
In the summer of 2004, a video survey was carried out in the northern part of the central mud bank (Grande Vasière) of the
Bay of Biscay to study the small scale relationship between the dominant crustacean megafauna Nephrops norvegicus, Munida rugosa and Goneplax rhomboides and juvenile hake (Merluccius merluccius). Using a towed body, high-resolution videos were recorded in six sampling sites. Statistical modelling using generalised
additive models (GAM) revealed variations in activity patterns for two species. More N. norvegicus were observed outside their burrows at dawn and somewhat at dusk (no observations during night) while G. rhomboides was less observed in the morning. In addition, reduced spatial overlap between G. rhomboides and N. norvegicus suggested reduced competition for food but also space as both are burrowing species. The observed temporal and spatial activity
patterns may contribute to regulating assemblage structure as competing species may be actively foraging at different times
and locations thus reducing direct competition. 相似文献
Estimating the amounts of resources consumed by individuals is important in many studies. For predators, allometric relationships
can be used to extrapolate the size of preys from undigested remains found in the stomach and in the faeces. However, such
equations are available for a limited number of species. Based on a large sample size gathered in New Caledonia on both predators
(sea kraits) and their preys (anguilliform fishes), we provide the first allometric relationships that allow estimating accurately
the mass and the size of various anguilliform fish species. 相似文献
We analyzed the movement of fishing vessels during fishing trips in order to understand how fishermen behave in space while searching for fish. For that purpose we used hourly geo-referenced positions of vessels, provided by a satellite vessel monitoring system, for the entire industrial fleet (809 vessels) of the world's largest single species fishery (Peruvian anchovy, Engraulis ringens) from December 1999 to March 2003. Observed trajectories of fishing vessels are well modeled by Lévy random walks, suggesting that fishermen use a stochastic search strategy which conforms to the same search statistics as non-human predators. We show that human skills (technology, communication, or others) do not result in the fishermen's spatial behavior being fundamentally different from that of animal predators. With respect to probability of prey encounter, our results suggest that fishermen, on average, evolved an optimal movement pattern (mu = 2.00) among the family of Lévy random walks. This Lagrangian approach opens several perspectives in terms of operational management of the pelagic fish stock. 相似文献
Reliable measurements of pollutant levels in the vicinity of a toll plaza appear to be rare. In order to assess the exposure
of toll booth operators to carbon monoxide, a continuous carbon monoxide monitor was installed at head height in the booth
of a medium density traffic lane at the Mariannhill toll plaza, situated on a busy highway near Durban, South Africa. Measurements
in excess of 500 ppmv were recorded and the high daily mean carbon monoxide concentrations may account for some of the symptoms
such as headaches and general malaise that have been reported by workers in the booths. Generally, carbon monoxide levels
recorded far exceed the recommended limit set by the South African authorities. These results have led to recommendations
regarding the structure of new and existing toll booths to minimize the exposure of toll booth workers to adverse effects
of vehicle-emitted pollutants. 相似文献
Static bioassays were made to determine acute toxicity of chlorpyrifos-methyl, a wide spectrum organophosphorus insecticide and potential toxic pollutant of aquatic ecosystem, Guppy fish (Poecilia reticulata). Bioassays were made at a regulated temperature of 22+/-1 degrees C and were repeated three times. Lethal doses of the insecticides were determined using LC50 software programme of U.S. EPA based on Finney's Probit Analysis statistical method. The 96 h LC50 value and 95% confidence limit of chlorpyrifos-methyl for Guppy was estimated as 1.79 (1.47-2.10) mg/l. The fish exposed to chlorpyrifos-methyl exhibited behavioral changes in the form of neurotoxin toxicity: less general activity than control group, loss of equilibrium, erratic swimming and staying motionless at a certain location generally at mid-water level for prolonged periods. The 1 mg/l (lowest) concentration had similar behavior (NOEC) with the control group. 相似文献
The effects on Chlorella sp. and Phaeodactylum tricornutum of two industrial wastewaters known to contain the herbicide residues of Trifluralin and Propanil have been determined by monitoring the number of cells, the chlorophyll fluorescence and the carbon dioxide assimilation simultaneously for a period of 14 days. The growth of the diatom, Phaeodactylum tricornutum, was inhibited by concentrations of herbicidal waste of the order of 0.1-0.5%, apparently because the rate of reproduction was reduced. Chlorella sp. cells, on the other hand, whilst dramatically inhibited by 1% concentrations of herbicidal waste, were able to recover over a period of 14 days. If discharged at concentrations below 0.01%, the industrial wastes appeared not to affect phytoplankton. 相似文献
Sediment cores from oxygen depleted zones of lake Léman (lake of Geneva) and from anoxic surface sediment from Voua de la Motte (France) were analyzed for their sterol compositions. 4-methylstanols were found to be major sterols in Motte lake sediment, which is rich in organic matter. In lake Léman, the relative abundances of the same 4-methylstanols increase with the depth in the core, but they remain always minor compounds. An extensive search for a possible external source for these compounds included the analysis of water, of the plankton and of the surrounding soil material. All these results, along with those of an in situ incubation experiment, give strong evidence in favor of their in situ bacterial biosynthesis. 相似文献