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71.
Fragrances are used in a wide array of everyday products and enter the aquatic environment via wastewater. While several musk compounds have been studied in detail, little is known about the occurrence and fate of other fragrances. We selected 16 fragrance compounds and scrutinized their presence in Bavarian sewage treatment plants (STP) influents and effluents and discussed their ecological risks for the receiving surface waters. Moreover, we followed their concentrations along the path in one STP by corresponding time-related water sampling and derived the respective elimination rates in the purification process. Six fragrance substances (OTNE, HHCB, lilial, acetyl cedrene, menthol, and, in some grab samples, also methyl-dihydrojasmonate) could be detected in the effluents of the investigated sewage treatment plants. The other fragrances under scrutiny were only found in the inflow and were eliminated in the purification process. Only OTNE and HHCB were found in the receiving surface waters of the STP in congruent concentrations, which exceeded the preliminary derived environmental thresholds by a factor of 1.15 and 1.12, respectively, indicating potential risks. OTNE was also detected in similar concentration ranges as HHCB in muscles and livers of fish from surface waters and from ponds that are supplied with purified wastewater. The findings show that some fragrance compounds undergo high elimination rates, whereas others—not only musks—are present in receiving surface water and biota and may present a risk to local aquatic biota. Hence, our results suggest that the fate and potential effects of fragrance compounds in the aquatic environment deserve more attention.  相似文献   
72.
This paper estimates rural household-level forest reliance in the western highlands of Guatemala using quantitative methods. Data were generated by the way of an in-depth household income survey, repeated quarterly between November 2005 and November 2006, in 11 villages (n = 149 randomly selected households). The main sources of income proved to be small-scale agriculture (53 % of total household income), wages (19 %) and environmental resources (14 %). The latter came primarily from forests (11 % on average). In the poorest quintile the forest income share was as high as 28 %. All households harvest and consume environmental products. In absolute terms, environmental income in the top quintile was 24 times higher than in the lowest. Timber and poles, seeds, firewood and leaf litter were the most important forest products. Households can be described as ‘regular subsistence users’: the share of subsistence income is high, with correspondingly weak integration into regional markets. Agricultural systems furthermore use important inputs from surrounding forests, although forests and agricultural uses compete in household specialization strategies. We find the main household determinants of forest income to be household size, education and asset values, as well as closeness to markets and agricultural productivity. Understanding these common but spatially differentiated patterns of environmental reliance may inform policies aimed at improving livelihoods and conserving forests.  相似文献   
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75.
Valuation of commercial central Himalayan medicinal plants   总被引:1,自引:0,他引:1  
Olsen CS 《Ambio》2005,34(8):607-610
This study estimates the national-level annual volume and value of commercial medicinal plant harvest in Nepal. Data were collected using open-ended questionnaires administered to local medicinal plant traders (n=149) in 15 districts in Nepal and regional wholesalers (n=53) in India. The annual trade volume is estimated to range from 7000 to 27 000 tons, with 14 500 tons harvested in the case year 1997-1998. The corresponding annual export value, calculated using regional wholesaler purchasing prices in the main markets in India, is estimated at US dollars 7-30 million, with a value of US$16 million in 1997-1998. Around 10% of rural households are involved in commercial harvesting. Lower ecological zones dominate supplies in both volume and value terms; herbs constitute the most important life form in value terms. Around 36% of volume and 51% of value derive from destructive harvesting. It is argued that annual volume and value figures are likely to be conservative estimates. The implications of findings for Himalayan medicinal plant conservation and trade are briefly discussed.  相似文献   
76.
Transformation products of 2-benzoxazolinone (BOA) in soil   总被引:1,自引:0,他引:1  
Three degradation experiments were performed to examine the formation of transformation products from 2-benzoxazolinone (BOA) in different soil types and concentrations. In two experiments using BOA in low concentration (400 microgkg(-1)) only one unidentified transformation product was found, whereas in the degradation experiment in high concentration (400 mgkg(-1)) several metabolites occurred. Two of these metabolites, 2-amino-(3H)-phenoxazin-3-one (APO); and 2-acetylamino-(3H)-phenoxazin-3-one (AAPO) were synthesized to prove their identity. This is the first time that the successive formation of these types of compounds from BOA is shown in soil. A number of other APO related transformation products were detected and provisionally characterized. The formation of APO, which is a much more biologically active compound than BOA, and the concurrent formation of a number of other APO-related metabolites in soil underline the importance of performing transformation studies as part of the evaluation of the effect of allelochemicals on weeds and soil-borne diseases.  相似文献   
77.
The SAFIRA in situ pilot plant in Bitterfeld, Saxonia-Anhalt, Germany, currently serves as the test site for eight different in situ approaches to remediate anoxic chlorobenzene (CB)-contaminated ground water. Two reactors, both filled with originallignite-containing aquifer material, are designed for themicrobiological in situ remediation of the ground water bythe indigenous microbial consortia. In this study, thehydrogeological, chemical and microbiological conditions of theinflowing ground water and reactor filling material are presented,in order to establish the scientific basis for the start of thebioremediation process itself. The reactors were put intooperation in June 1999. In the following, inflow CB concentrationsin the ground water varied between 22 and 33 mg L-1; achemical steady state for CB in both reactors was reachedafter 210 till 260 days operation time. The sediments werecolonized by high numbers of aerobic, iron-reducing anddenitrifying bacteria, as determined after 244 and 285 days ofoperation time. Furthermore, aerobic CB-degrading bacteria weredetected in all reactor zones. Comparative sequence analysis of16S rDNA gene clone libraries suggest the dominance of Proteobacteria (Comamonadaceae, Alcaligenaceae, Gallionella group, Acidithiobacillus) and members of theclass of low G+C gram-positive bacteria in the reactorsediments. In the inflowing ground water, sequences withphylogenetic affiliation to sulfate-reducing bacteria andsequences not affiliated with the known phyla of Bacteria, were found.  相似文献   
78.
Biodiversity studies that guide agricultural subsidy policy have generally compared farming systems at a single spatial scale: the field. However, diversity patterns vary across spatial scales. Here, we examined the effects of farming system (organic vs. conventional) and position in the field (edge vs. center) on plant species richness in wheat fields at three spatial scales. We quantified alpha-, beta-, and gamma-diversity at the microscale in 800 plots, at the mesoscale in 40 fields, and at the macroscale in three regions using the additive partitioning approach, and evaluated the relative contribution of beta-diversity at each spatial scale to total observed species richness. We found that alpha-, beta-, and gamma-diversity were higher in organic than conventional fields and higher at the field edge than in the field center at all spatial scales. In both farming systems, beta-diversity at the meso- and macroscale explained most of the overall species richness (up to 37% and 25%, respectively), indicating considerable differences in community composition among fields and regions due to environmental heterogeneity. The spatial scale at which beta-diversity contributed the most to overall species richness differed between rare and common species. Total richness of rare species (present in < or = 5% of total samples) was mainly explained by differences in community composition at the meso- and macroscale (up to 27% and 48%, respectively), but only in organic fields. Total richness of common species (present in > or = 25% of total samples) was explained by differences in community composition at the micro- and mesoscale (up to 29% and 47%, respectively), i.e., among plots and fields, independent of farming system. Our results show that organic farming made the greatest contribution to total species richness at the meso (among fields) and macro (among regions) scale due to environmental heterogeneity. Hence, agri-environment schemes should exploit this large-scale contribution of beta-diversity by tailoring schemes at regional scales to maximize dissimilarity between conservation areas using geographic information systems rather than focusing entirely at the classical local-field scale, which is the current practice.  相似文献   
79.
The subterrestrial groundwater treatment (in situ treatment) is a multifunctional technology which is effective for the removal of such water constituents as iron, manganese, arsenic and ammonia. The in situ treatment can be applied efficiently for decentralised water supply. Within the framework of a research project, biofilms which play an important role in the in situ treatment will be localised, isolated and examined. Microorganisms will be identified and characterised in order to make the in situ treatment controllable regarding both planning and design of facilities, and to increase the efficiency of the technology.  相似文献   
80.
One of the basic principles of sexual selection is that male reproductive success should be skewed towards strong males in species with anisogamous sex. Studies on primate multi-male groups, however, suggest that other factors than male fighting ability might also affect male reproductive success. The proximate mechanisms leading to paternity in multi-male primate groups still remain largely unknown since in most primate studies mating rather than reproductive success is measured. Furthermore, little research focuses on a female’s fertile phase. The aim of this study was to investigate the relative importance of male monopolisation and female direct mate choice for paternity determination. We also investigated the extent to which paternity was decided post-copulatory, i.e. within the female reproductive tract. We used a combined approach of behavioural observations with faecal hormone and genetic analysis for assessment of female cycle stage and paternity, respectively. The study was carried out on a group of wild long-tailed macaques living around the Ketambe Research Station, Gunung Leuser National Park, Indonesia. Our results suggest that both male monopolisation and post-copulatory mechanisms are the main determinants of male reproductive success, whereas female direct mate choice and alternative male reproductive strategies appear to be of little importance in this respect. Female cooperation may, however, have facilitated male monopolisation. Since paternity was restricted to alpha and beta males even when females mated with several males during the fertile phase, it seems that not only male monopolisation but also post-copulatory mechanisms may operate in favour of high-ranking males in long-tailed macaques, thus reinforcing the reproductive skew in this species.  相似文献   
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