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Education is an established tool to enhance human–environment relationships, despite the lack of empirical evidence to support its use. We used theories of change to unpack assumptions about the role of education in conservation. We interviewed practitioners from 15 conservation organizations in Madagascar to typify implicit pathways of change and assess whether emerging pathways echo theoretical advances. Five pathways were drivers of change: increasing knowledge, changing emotional connection and changing traditional cultural practices, fostering leaders, diversifying outcomes, and influencing community and society. These pathways reflect existing sociopsychological theories on learning and behavioral change. Most interviewees’ organizations had a predominant pathway that was often combined with elements from other pathways. Most pathways lacked culturally grounded approaches. Our research reveals assumptions about the role of education in conservation and indicates that organizations had different ideas of how change happens. The diversity of practices reflects the complexity of factors that influence behavior. Whether this diversity is driven by local sociocultural context, interaction with other conservation approaches, or contingencies remains unclear. Yet, typifying the pathways of change and reflecting on them is the first step towards comprehensive evaluation of when and which pathways and interactions to promote.  相似文献   
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Needles of 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied in an ultraviolet (UV) exclusion field experiment (from 2000 to 2002) in northern Finland (67 °N). The chambers held filters that excluded both UV-B and UV-A, excluded UV-B only, transmitted all UV (control), or lacked filters (ambient). UV-B/UV-A exclusion decreased nitrate reductase (NR) activity of 1-year-old needles of Scots pines compared to the controls. The proportion of free amino acids varied in the range 1.08-1.94% of total proteins, and was significantly higher in needles of saplings grown under UV-B/UV-A exclusion compared to the controls or UV-B exclusion. NR activity correlated with air temperature, indicating a “chamber effect”. The study showed that both UV irradiance and increasing temperature are significant modulators of nitrogen (N) metabolism in Scots pine needles.  相似文献   
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Abstract: Genetic diversity is expected to decrease in small and isolated populations as a consequence of bottlenecks, founder effects, inbreeding, and genetic drift. The genetics and ecology of the rare perennial plant Lychnis viscaria (Caryophyllaceae) were studied in both peripheral and central populations within its distribution area. We aimed to investigate the overall level of genetic diversity, its spatial distribution, and possible differences between peripheral and central populations by examining several populations with electrophoresis. Our results showed that the level of genetic diversity varied substantially among populations (  H exp = 0.000–0.116) and that the total level of genetic diversity (mean H exp = 0.056) was low compared to that of other species with similar life-history attributes. The peripheral populations of L. viscaria had less genetic variation (mean H exp = 0.034) than the central ones (0.114). Analysis of genetic structure suggested limited gene flow (mean F ST = 0.430) and high differentiation among populations, emphasizing the role of genetic drift (  N e m = 0.33). Isolation was even higher than expected based on the physical distance among populations. We also focused on the association between population size and genetic diversity and possible effects on fitness of these factors. Population size was positively correlated with genetic diversity. Population size and genetic diversity, however, were not associated with fitness components such as germination rate, seedling mass, or seed yield. There were no differences in the measured fitness components between peripheral and central populations. Even though small and peripheral populations had lower levels of genetic variation, they were as viable as larger populations, which emphasizes their potential value for conservation.  相似文献   
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The aim of this study was to evaluate the suitability of in vitro enzymatic methods for assaying the biodegradability of new starch-based biopolymers. The materials studied included commercial starch-based materials and thermoplastic starch films prepared by extrusion from glycerol and native potato starch, native barley starch, or crosslinked amylomaize starch. Enzymatic hydrolysis was performed using excessBacillus licheniformis -amylase andAspergillus niger glucoamylase at 37°C and 80°C. The degree of degradation was determined by measuring the dissolved carbohydrates and the weight loss of the samples. Biodegradation was also determined by incubating the samples in a compost environment and measuring the weight loss after composting. The results indicated that the enzymatic method is a rapid means of obtaining preliminary information about the biodegradability of starch-based materials. Other methods are needed to investigate more accurately the extent of biodegradability, especially in the case of complex materials in which starch is blended with other polymers.  相似文献   
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The pesticide atrazine,its degradation products,and 2,6-dichlorobenzamide(BAM) are persistent in groundwater environment.We studied whether their dissipation can be enhanced with a mixture of a complex carbon source and zero-valent iron(ZVI) called EHC.The application rates were 1.0% and 2.0%(by weight) in subsurface sediments slurries(atrazine 30 mg/L),and 2.0% in 1.5 m pilot-scale sediment columns with groundwater flowing through(atrazine 0.08,desethylatrazine DEA 0.03,BAM 0.02 μg/L).In the slurries under aerobic conditions,atrazine of 0.88 ± 0.14 mg/g of EHC was dissipated chemically,as concentrations did not differ significantly between the slurries and their sterilized controls.No degradation occurred in the slurries under anaerobic conditions.In the pilot-scale columns under water-saturated conditions,atrazine,DEA and BAM were not detected in effluents during 33,64 and 64 days from the beginning of the water flow through EHC columns,respectively,but thereafter traces of compounds could be detected.No atrazine or degradation products(BAM,DEA,deisopropylatrazine,desethyldeisopropylatrazine) could be extracted from the column sediments at the end of the experiment.As a result,the sum of dissipated pesticides was about7.6 μg/g of EHC in columns under water-saturated conditions,and 0.88 mg/g of EHC in slurries under aerobic conditions.EHC can be used to enhance the dissipation of studied pesticides in small quantities,preferentially under aerobic conditions.  相似文献   
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We studied the effects of elevated O3 (40-50 ppb) and CO2 (+100 ppm) alone and in combination on the growth onset, relative chlorophyll meter values, and reproductive development of meadow species grown in ground-planted mesocosms using open-top chambers. The 3-year study was conducted in the summers of 2002-2004. Elevated O3 decreased the early season coverage of plant communities and delayed the flowering of Campanula rotundifolia and Vicia cracca. The relative chlorophyll meter values of Fragaria vesca leaves were decreased by O3. Ozone also reduced the overall number of produced flowers, but as far as individual species were concerned, O3 had significant effects only on Campanula rotundifolia. In the case of Fragaria vesca, O3 decreased the fresh weight of individual berries. The effects of CO2 were less pronounced, and CO2 generally did not ameliorate the negative effects of O3. Changes in reproduction may affect the long-term fate of the whole community.  相似文献   
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了解各种环境条件下控制生物多样性的机制是当今科学领域里最大的挑战之一.与陆地和底栖生境相比,对调节浮游生物生态系统物种多样性的机制的研究比较少.这主要是因为缺乏现场研究中的实验证据,因为这些实验证据覆盖了大量的时空尺度,并有足够的分辨率.本文通过陆地/相连系统的比较,讨论了作为浮游植物生长环境的水生系统的特性,列举了波罗的海中物种多样性的调节机制.  相似文献   
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We studied the effects of relatively low levels of O(3) (40-50 ppb) and CO(2)-enrichment (+100 ppm) on a northern European lowland hay meadow during the summers 2002-2004 using open-top chambers (OTCs) and ground-planted mesocosms. Ozone reduced the aboveground biomass of the community (up to 40%), and four out of seven species (Campanula rotundifolia, Fragaria vesca, Trifolium medium, Vicia cracca) showed either significant growth reduction and/or visible injuries under elevated O(3). However, the reductions in aboveground biomass were not reflected as changes in the dominance of different functional groups or in the total community root biomass. Elevated CO(2) did not amend the detrimental effects of O(3) on aboveground biomass. Elevated CO(2) alone had only minor effects. An O(3)-induced reduction in the aboveground biomass and N pool of the community are likely to have important consequences in the nutrient cycling of the ecosystem.  相似文献   
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