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141.
Wolfgang Strasdas 《生态毒理学报》2002,(4):12-15
定义
围绕这个主题 , 虽然有很多不同的看法 , 笔者却认为 , 由于具有一整套明确目标 , “ 生态旅 游 “ 应该被认作是一个可以发展的概念 , 没必要把它当作一个市场 ( 市场指得是 “ 大自然旅 游 “ ) . 因此 , 生态旅游被认定为大自然旅游的一种具有可持续能力的形式 , 力争得到环境 、社会和文化的和谐共处 , 以及创造经济和其他的效益 , 特别是在为当地农村居民造福和自 然保护方面 .
…… 相似文献
142.
The capability of different white rot (WR, Heterobasidion annosum, Phanerochaete chrysosporium, Trametes versicolor) and ectomycorrhizal (ECM, Paxillus involutus, Suillus bovinus) fungal species to degrade different aromatic compounds and the absorption of 3-chlorobenzoic acid (3-CBA) by ECM pine seedlings was examined. The effect of aromatic compounds on the fungal biomass development varied considerably and depended on (a) the compound, (b) the external concentration, and (c) the fungal species. The highest effect on the fungal biomass development was observed for 3-CBA. Generally the tolerance of WR fungi against aromatic compounds was higher than that of the biotrophic fungal species. The capability of different fungi to degrade aromatic substances varied between the species but not generally between biotrophic and saprotrophic fungi. The highest degradation capability for aromatic compounds was detected for T. versicolor and H. annosum, whereas for Phanerochaete chrysosporium and the ECM fungi lower degradation rates were found. However, Paxillus involutus and S. bovinus showed comparable degradation rates at low concentrations of benzoic acid and 4-hydroxybenzoic acid. In contrast to liquid cultures, where no biodegradation of 3-CBA by S. bovinus was observed, mycorrhizal pines inoculated with S. bovinus showed a low capability to remove 3-CBA from soil substrates. Additional X-ray microanalytical investigations showed, that 3-CBA supplied to mycorrhizal plants was accumulated in the root cell cytoplasm and is translocated across the endodermis to the shoot of mycorrhizal pine seedlings. 相似文献
143.
Schwitzguébel JP Aubert S Grosse W Laturnus F 《Environmental science and pollution research international》2002,9(1):62-72
Many synthetic sulphonated aromatic compounds are used as starting material to produce dyes and pigments, or are released as by-products in the effluents of the textile and dye industry. A large number of these chemicals are poorly biodegradable and cannot be eliminated by classical wastewater treatment plants. To limit the impact of these pollutants on the environment, new processes, based on the use of higher plants (constructed wetlands or hydroponic systems), are under development. Detergents and surfactants are essential for both industrial and domestic applications, the most important family being the alkylbenzene sulphonates. Originally, the alkyl side chains were branched and thus recalcitrant to biodegradation. Therefore, they have been replaced by linear alkylbenzene sulphonates. Although more acceptable, present formulations still have adverse environmental and toxic effects. In this context, phytoremediation appears to be a promising approach to remove these compounds from contaminated soils and waters. 相似文献
144.
Roswitha Wiltschko Richard Kumpfmüller Renate Muth Wolfgang Wiltschko 《Behavioral ecology and sociobiology》1994,35(1):63-73
This analysis is based on 103 releases with 6-h clock-shifted pigeons of various ages and experiences. Resetting the internal clock normally leads to a significant change in initial orientation; however, in half of the cases, the induced deflections are significantly smaller than predicted by the sun compass hypothesis. The relative size of the deflections decreases with increasing age and experience (Fig. 3). Only young pigeons with limited experience respond as expected, while old birds show deflections which are, on the average, only slightly more than half of the predicted size, except at extremely familiar sites (Table 2). There is no difference between fast and slow shifts (Fig. 4). It is not possible to clearly specify under what circumstances smaller deflections occur; previous clock-shifts (Fig. 5), familiarity with the release site (Table 4) and duration of the shifting procedure (Table 5) do not seem to be the reasons. Clock-shifting also tends to decrease the vector lengths and has a marked effect on homing performance (Table 7). Nevertheless, considerable numbers of clock-shifted birds return on the day of release before their internal clock has begun to be reset back to normal. The general role of the sun compass in bird orientation is considered and theoretical implications of our findings are discussed in view of the map and compass-model and the possibility that an alternative, non-time-compensating compass is used in parallel with the sun compass. 相似文献
145.
Wolfgang Wiltschko Roswitha Wiltschko William T. Keeton 《Behavioral ecology and sociobiology》1984,15(4):263-272
Summary A group of experienced homing pigeons vas subjected to a 6 h slow shift of their internal clock and kept under these conditions for more than 2 months. During the overlap time between the natural and artificial photoperiods they were released for training flights to familiarize them with an area while living in a permanent shift.Tested outside the permanent shift training range, the experimentals always deviated about 30° clockwise from the mean of their controls, markedly less than in a regular 6 h slow shift. Inside the permanent shift training range, however, they oriented like the controls (Fig. 2). When their internal clock was returned to normal, the birds showed a larger counterclockwise deflection on their first flight, which was roughly comparable to the effect of a regular 6 h fast shift (Fig. 3). On later flights after normalization, this large shift was no longer found; instead we observed a roughly 30° counterclockwise deflection when they were released inside the permanent shift training range in the morning. This deflection did not seem to occur in the afternoon or outside the permanent shift training range (Figs. 4, 5), and it disappeared when the birds were repeatedly released from the same site (Fig. 6).The occurrence or non-occurrence of the deflection was independent of the duration of the shift or the time passed after normalization; it seemed to depend solely on whether the birds had become familiar with a given site in the situation of the permanent shift. This argues against an effect based on the sun compass. We tend to assume that the still unknown navigational map is involved. In this case, however, as the deflection is independent of the home direction and the type of release site bias, the factors in question would act very differently from the gradients on which the traditional concepts of the navigational map are based. The processes establishing and updating the map and their possible differences are discussed.Died on August 17, 1980 相似文献
146.
Anne Theenhaus Reinhard Zeitler Wolfgang von Brackel Helmut -Julius Botsch Wolfgang Baumeister Ludwig Peichl 《Environmental Sciences Europe》2002,14(4):229-236
Ecological monitoring of genetically engineered plants (GEPs) is being developed in the Bavarian Environmental Protection Agency. Focusing on oilseed rape (Brassica napus, Cruciferae), a method is being established to measure the impact of the commercial release of GEPs on plant communities. Oilseed rape is known to escape from cultures and to establish outside the fields. It also produces hybrid offspring with wild relatives of the European flora. The study site is located in Bavaria (Germany) and comprises an area of 5700 ha. It is characterized by a mosaic of protected natural habitats in close vicinity to intensively cultivated farmland. In this region species composition and population density of Cruciferae is documented prior to a possible commercial release of GEPs. Furthermore Cruciferae of the study site are tested for the presence of transgenes. Therefore, plant material of selected Cruciferae is randomly sampled. We also test oilseed rape honey from the study site and pollen from pollen traps for the presence of hybrid pollen. The molecular method used is the ‘real-time PCR’. In addition, an intensive monitoring program is established in two types of biotopes, which are located in the study site. Multivariate statistics are being used to correlate plant community data with soil parameters. 相似文献
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