南非两个自然旅游经营项目中的当地社区受益体系

南非的两个自然旅游经营项目 - - 尼加拉私人狩猎保护区和洛克泰尔湾已经建立了完全不同 的当地社区受益体系 .一个是靠独立的外部捐款资助 , 另一个是通过分红利 .本文阐述了利益 管理机制以及每个体系对附近居民的影响 .居民的一些受益 ( 如就业、企业家机遇、资源利用 、对传统仪式的支持 ) 与正式的社区受益体系没有直接关系 .     

Encounters between Antarctic limpets, <Emphasis Type="Italic">Nacella concinna</Emphasis>, and predatory sea stars, <Emphasis Type="Italic">Lysasterias</Emphasis> sp., in laboratory and field experiments

Antarctic limpets, Nacella concinna, from the Admiralty Bay (King George Island, South Shetlands) for at least part of the year (austral winter) co-exist with predatory sea stars Lysasterias sp. Our laboratory and field experiments established that the presence of Lysasterias sp. or its odour had considerable influence upon their behaviour. Limpets’ responses, consisting of shell mushrooming, shell rotation and flight, were distinctly different from their reaction to other stimuli, such as food and conspecific odours, or mechanical stimulation. Moreover, a significant impact of sea star presence on limpets’ activity was observed, with limpets fleeing to a distance of 60 cm from the predator. Such reactions allow limpets to lower the incidence of sea star predation, but at the cost of presumptive disrupting of foraging and an additional energy expended for locomotion. A visible difference was noted between two limpet populations, with the rockpool limpets responding only after physical contact with being touched by a sea star, and the subtidal ones responding at a distance of up to 20 cm.     

Phaeocystis blooms and eutrophication of the continental coastal zones of the North Sea

It is suggested that novel nuisance algal blooms can result from major shifts in N/P or NH₄ ⁺/NO₃ ^- ratios. Inland hydraulic engineering caused a shift from P-limitation (before 1977) towards N-limitation (after 1977) in the Marsdiep area (Dutch coastal waters). Following this shift the colonial flagellate Phaeocystis sp. became more abundant and started to bloom during the nutrient-controlled period (later spring to autumn). Competition experiments showed that the N/P ratio can influence the species composition of marine phytoplankton. In addition, the natural distribution of some species like Rhodomonas sp. and Emiliania huxleyi may be affected by the frequency of nutrient pulses in the system. Phaeocystis was a poor competitor under P-limitation and a good competitor under N-limitation. Colony formation was absent under P- and NH₄ ⁺-limitation. Colonies were formed under NO₃ ^--limitation. These preliminary results suggest that colony-forming Phaeocystic blooms may be restricted (besides light-controlled environments) to those N-controlled environments where nitrate is consumed by Phaeocystis. The distribution of Phaeocystis along the European continental coast is evaluated on the basis of its ability to compete for nutrients and to form colonies when nitrate is the major N-source.     

Moon orientation in sandhoppers: effects of lighting treatments on the persistence of orientation ability

The moon orientation rhythm persists in sandhoppers removed from environmental entrainments relative to moon periodicity. In order to investigate the underlying mechanism, the crustacean amphipods Talorchestia capensis and Talitrus saltator were collected at new moon and exposed in the laboratory to an artificial light during the day, but to a variety of lighting treatments during the night: (1) continuous dark, (2) dim light in phase with the natural moon, (3) continuous dim light. The animals were tested under the moon 9–21 days later by using a new type of arena. The ability to orientate in a direction perpendicular to the shore persisted in sandhoppers under treatments 1 and 2, but not under treatment 3. A disturbance due to a phototactic tendency in Talorchestia was also observed in animals captured on the day of the test when exposed to unnatural lighting, but not when they were kept under natural light. The present findings show that the timing mechanism allowing compensation for changes in the moon’s position also persists in animals that have been long removed from entraining factors. The dependence of this orientation ability on nocturnal lighting and the disturbing effect of sudden changes in light intensity support the idea that the phasal lighting of the moon, and perhaps sunrise and sunset act as resetting factors for the moon’s orientation rhythm.     

The influence of sorption material preparation on the removal of metal ions from the aqueous solution

ABSTRACT

Very important in adsorption processes is the preparation of material sorbents and from this reason, the impact of washing agent of raw sorbent was analysed. The adsorption capacity was studied in relation to the function of the equilibrium time, the amount of biosorbent and the initial metal(II) ions concentration. In this research for the sake of comparison, the sorptive properties of out-of-date coffee were compared to coffee washed with different agents (mineral acids and water). The scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterise the biosorbents and to identify the functional groups that participated in metal(II) ions bonding. The obtained results clearly indicate that the out-of-date coffee are effective biosorbent for cadmium(II) and nickel(II) ions from aqueous solution. However, for metal(II) ions removal efficiency could influence sorbent preparation and nickel(II) ions were best adsorbed on coffee washed with water, but cadmium(II) ions on raw biosorbent (out-of-date coffee). The best results of sorption were achieved after the contact time of 30 and 60?min, respectively for cadmium(II) and nickel(II) ions.     

An actor game on implementation of environmental quality standards for nitrogen in a Swedish agricultural catchment

Despite political efforts, diffuse pollution from agriculture continues to be the single largest source of nitrogen (N) emissions into the aquatic environment in many countries and regions. This fact, and the recent enactment of a new Swedish environmental code, led to the design of a study targeted at the evaluation of new N pollution abatement strategies. An actor game was chosen as the key component of the study, with a focus on four major goals: to test the implementability of legally binding environmental quality standards for nitrate concentration in groundwater and N transport to the sea, to find sets of agriculturally feasible and cost-effective measures to decrease N loads, to investigate the possibilities for collective action through negotiated and institutionalized actor cooperation, and to investigate the role of mathematical modeling in environmental N management. Characteristics from the agriculturally dominated catchment of Genevads?n (224 km2) on the southwest coast of Sweden served as the playing field for the actor game. The most noteworthy result from the study was that it appeared to be possible to meet ambitious environmental N standards with less economically drastic measures than anticipated by most of the participants. The actor game was shown to be a good method for learning about the new Swedish environmental code and its application and for gaining deeper insight into the issues of N management. In addition, the actor game functioned as an arena for gaining a more thorough understanding of the views of different stakeholders.     

The tail feathers of osprey nestlings (Pandion haliaetus L.) as indicators of change in mercury load in the environment of southern Sweden (1969-1998): a case study with a note on the simultaneous intake of selenium

The tail feathers of 104 osprey nestlings (Pandion haliaetus) from Lake Asnen, southern Sweden, were analyzed for total mercury and selenium content. Concentrations of mercury in feathers from the western part of the lake fell during the period 1969-1998, when pollution from industrial mercury had decreased and a paper mill upstream of the lake was closed down in 1979. Nestlings from the eastern part of the lake had initially lower levels of mercury, predominantly from atmospheric fallout. The levels did not decrease during the period. The reason for the differences seems to be the limited water flow between the western and the eastern part of the lake. The selenium concentrations were constant over time and approximately the same in both parts of the lake. The total-Hg/Se ratio in the western part of the lake was 2.94, which is somewhat higher than the 1:1 molar ratio constant (2.54). This indicates that the bioaccumulated quantity of selenium which is thought to be protective for the organisms against the toxic effects of mercury, is somewhat insufficient to bind all body mercury.     

Monitoring of toxicity during degradation of selected pesticides using ionizing radiation

The optimization of experimental conditions for radiolytic removal of organic pollutants from water and waste with the use of ionizing radiation via controlling the concentration of target compound(s) requires also monitoring the toxicity changes during the process. Commonly used herbicides 2,4-D and dicamba were shown to increase toxicity measured with the Microtox test at low irradiation doses resulting from formation of more toxic transient products, which can be decomposed at larger doses. The changes of toxicity were examined with respect to dose magnitude and the presence of commonly occurring scavengers of radiation.     

Occurrence and abatement of volatile sulfur compounds during biogas production

Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, which were subsequently analyzed using gas chromatography in combination with mass spectrometry. Other volatile organic compounds present also were identified. The most commonly occurring VSCs in the biogas were hydrogen sulfide, carbonyl sulfide, methanethiol, dimethyl sulfide, and dimethyl disulfide, and hydrogen sulfide was not always the most abundant sulfur (S) compound. Besides VSCs, oxygenated organic compounds were commonly present (e.g., ketones, alcohols, and esters). The effect of adding iron chloride to the biogas reactor on the occurrence of VSCs also was investigated. It was found that additions of 500-g/m3 substrate gave an optimal removal of VSCs. Also, the use of a prefermentation step could reduce the amount of VSCs formed in the biogas process. Moreover, in the carbon dioxide scrubber used for upgrading the gas, VSCs were removed efficiently, leaving traces (ppbv levels). The scrubber also removed other organic compounds.