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101.
102.
Ben Drake James C. R. Smart Mette Termansen Klaus Hubacek 《Regional Environmental Change》2013,13(3):649-659
Many regulating ecosystem services exhibit non-excludability and non-rivalry characteristics akin to public goods. This makes it unlikely that such regulating ecosystem services will attract a price in the marketplace. Policymakers, therefore, find difficulties in determining a correct economic valuation for regulating ecosystem services, with potentially severe consequences for aligning policy for ecosystem service provision with public preferences for service delivery. This research used a choice modelling approach to estimate public preferences for delivery of two regulating ecosystem services; reductions in the flood risk to the British city of York (implemented by filling in drainage ditches in peat moorland further up the catchment), and a reduction in CO2 emissions (implemented by planting Poplar trees for biomass either locally in the study area or elsewhere in the UK). The choice experiment presented respondents with options providing different levels of CO2 reduction, implemented locally or nationally, and different levels of flood risk reduction, at a range of different prices, with a tax as the payment vehicle. Subsequent analysis with latent class (LC) models showed considerable heterogeneity of preference among respondents, particularly with regard to the location of tree planting for CO2 reduction. One LC segment showed a significant preference for achieving a high level CO2 reduction through national, as opposed to local tree planting, potentially indicating the existence of NIMBYism. The same LC segment displayed a preference for moderate reductions in the flood risk to York, even though this would deliver no personal benefit for a substantial proportion of the segment. This could, therefore, indicate altruistic behaviour towards geographically proximate beneficiaries. 相似文献
103.
Ben Vanpeperstraete Sébastien Duyck Medani P. Bhandari Janis Brizga Leida Rijnhout Sylvia Lorek A. Peter Castro Chiung Ting Chang Herman Daly Robert J. Didham Gianluca Ferraro Oliver Greenfield Ashok Khosla Ernst Ulrich von Weizsäcker Birgit Lode Simon Miles Henrique Pacini Semida Silveira Leisa Perch Jaap Rijnsburger Mukul Sanwal Sameera Savarala S. Jacob Scherr Kallidaikurichi E. Seetharam A.M.M. Adeeb Donna Shepherd Adrian Smith Lisinka Ulatowska Alice Vincent Werner John 《Natural resources forum》2011,35(4):334-342
104.
测定了采自香港2株球形棕囊藻和湛江1株等鞭金藻质体16SrDNA基因序列,结合GenBank中下载的32条同源序列,分析序列特征并构建分子系统树。发现600bp序列中有可变位点42个,简约信息位点33个,可变位点和简约信息位点分别为全序列的7.0%和5.5%。A+T的含量(52.5%)略大于C+G含量(47.5%),与已报道的棕囊藻属叶绿体和线粒体基因相似;在分子系统树上,同属藻种聚类在一起,属间遗传距离分别为0.0255-0.0503。棕囊藻属属内遗传距离0-0.0050,不同藻种相混杂,并未独立成支;质体16srDNA部分序列虽不能区分棕囊藻属内不同藻种,但能鉴定出GenBank中27个环境样品为棕囊藻属藻株,从而能确定其地理分布和相对丰度,对棕囊藻赤潮的预测预报具有重要意义。质体16srDNA在其他赤潮藻类物种鉴定方面的应用需要进一步研究。 相似文献
105.
I. Ben TaloubaL. Balland N. Mouhab M.A. Abdelghani-Idrissi 《Journal of Loss Prevention in the Process Industries》2011,24(4):391-396
The thermal stability of organic peroxides (cumene hydroperoxide 80 wt% and dicumyl peroxide) was studied by means of calorimetric measurement (DSC, TA Q1000) in an isotherm mode and a dynamic mode. Analysis of power profiles released in the isothermal mode was combined with the analysis of the decomposed compounds by a gas chromatograph/mass spectrometer (GC/MS) to determine the reaction mechanisms corresponding to each of the two reactions. In this work, a methodology for estimating kinetic parameters was based on the comparison of the power profile (dynamic mode) given by the model to that obtained experimentally by changing the parameters values. Parameter estimation is achieved using the mixed estimation method where a genetic algorithm is combined with a locally convergent method. 相似文献
106.
Ben B. Chapman Lesley J. Morrell Jens Krause 《Behavioral ecology and sociobiology》2009,63(12):1757-1763
The environment is profoundly important in shaping many aspects of animal phenotype, including courtship and mating behaviours.
Courtship displays rely upon the transmission of visual information from the signaller to the receiver, which means they are
likely to be less effective in visually poor conditions such as at low light or in turbid ecosystems. One might therefore
predict that in visually poor environments it would be beneficial for individuals to plastically adjust their mating behaviour
to maximise mating success. Here, we investigate the impact of the developmental and current visual environment (light intensity)
upon male mating behaviour in the Trinidadian guppy Poecilia reticulata. Male guppies have two different mating tactics: They can court females with a visual sigmoid display or attempt to circumvent
female choice by attempting a non-consensual copulation (gonapodium thrust). We reared juvenile guppies in low light and relatively
high light intensities for 5 months before observing individual males for mating behaviour in both light conditions. We found
that the current light environment is important in determining the frequency of both sigmoidal courtship displays and non-consensual
copulation attempts. Males increase the frequency of sigmoidal displays at relatively high light and increase non-consensual
mating attempts at low light, suggesting that males compensate for poor visual conditions via an adjustment in tactics. We
also find a significant correlation in courtship effort between the different light environments, suggesting that there is
individual consistency across time and context for this trait. Developmental environment was less important. However, we found
that fish reared at lower light intensities continued to employ sigmoidal displays despite the poor current visual environment.
Our data show that male mating behaviour is phenotypically plastic in response to recent light environment. This may have
implications for understanding how animals cope with anthropogenic environmental change. 相似文献
107.
Erin H. Gillam Gary F. McCracken John K. Westbrook Ya-Fu Lee Michael L. Jensen Ben B. Balsley 《Behavioral ecology and sociobiology》2009,64(1):69-79
Bats alter their echolocation in response to changes in ecological and behavioral conditions, but little is known about how
they adjust call structure in response to changes in altitude. We examined altitudinal variation in the echolocation of Brazilian
free-tailed bats, Tadarida brasiliensis, a species known to fly to altitudes of 3,000 m above the ground. From 50.2 h of recordings, we analyzed 113 high-quality
echolocation call sequences recorded from 0 to 862 m above ground level. Bats flying near the ground used shorter, higher-frequency,
broader-bandwidth calls compared to bats at higher altitudes, an effect likely due to the greater levels of echo-producing
clutter (i.e., vegetation, buildings) found near the ground. When ground-level recordings are excluded, bats continue to shift
towards the use of longer-duration, lower-frequency, narrower-bandwidth calls with increasing altitude. We propose that the
observed high-altitude changes in call structure are a response to changing acoustic attenuation rates and/or decreasing insect
densities at higher altitudes. 相似文献
108.
Due to the lack of data on hydraulic-jump dynamics in very large channels, the present paper describes the main characteristics
of the velocity field and turbulence in a large rectangular channel with a width of 4 m. Although a hydraulic jump is always
treated as a wave that is transversal to the channel wall, in the case of this study it has a trapezoidal front shape, first
starting from a point at the sidewalls and then developing downstream in an oblique manner, finally giving rise to a trapezoidal
shape. The oblique wave front may be regarded as a lateral shockwave that arises from a perturbation at a certain point of
the lateral wall and travels obliquely toward the centreline of the channel. The experimental work was carried out at the
Coastal Engineering Laboratory of the Water Engineering and Chemistry Department of the Technical University of Bari (Italy).
In addition to the hydraulic jump formation, a large recirculating flow zone starts to develop from the separating point of
the lateral shock wave and a separate boundary layer occurs. Intensive measurements of the streamwise and spanwise flow velocity
components along one-half width of the channel were taken using a bidimensional Acoustic Doppler Velocimeter (ADV). The water
surface elevation was obtained by means of an ultrasonic profiler. Velocity vectors, transversal velocity profiles, turbulence
intensities and Reynolds shear stresses were all investigated. The experimental results of the separated boundary layer were
compared with numerical predictions and related work presented in literature and showed good agreement. The transversal velocity
profiles indicated the presence of adverse pressure gradient zones and the law of the wall appears to govern the region around
the separated boundary layer. 相似文献
109.
基于三维荧光光谱技术解析不同微生物法净化黑臭水体的效果 总被引:2,自引:0,他引:2
应用曝气、菌剂+曝气、生物促生剂+曝气、菌剂+生物促生剂+曝气4种微生物技术净化黑臭水体,分别考察了进水中溶解性有机物(DOM)的特征和来源及出水中DOM的特征和效果,采用三维荧光(EEM)光谱技术与平行因子(PARAFAC)模型相结合的方式对进出水DOM进行了分析。结果表明,不同处理方式下进出水DOM的不同组分荧光峰强度变化存在较明显的差异,经过菌剂和生物促生剂联合处理之后,对类腐殖质等难降解物质削减效果最好。FI、HIX和BIX指数分析表明各处理水样中的DOM整体处于较强的自生源特征。利用主成分分析法(PCA)对影响黑臭水体DOM的主要因素及其贡献量研究发现:第1主成分表现为陆源类腐殖质和生物源类腐殖质共存的现象,对水体中DOM的贡献率为54.98%;第2主成分反映了以微生物代谢过程为代表的内源污染,对水体中DOM的贡献率为26.56%。因此,利用三维荧光分析能够较好的反映水中DOM的去除情况,易于实时在线监测,对黑臭水治理具有重要意义。 相似文献
110.
Manuel Benítez 《Ambio-人类环境杂志》2002,31(4):285-294
本文概述了引起萨尔瓦多红树林退化的各种因素,并分析了拟议中的红树林产权变化对贫困的海岸带社区红树林的意义.目前萨尔瓦多红树林生态系统的采伐和转化模式可通过补贴权利的透镜来观察,这种补助就是为特定用途向一些参与者授予财产权(而不授权给别人).遗憾的是,对红树林资源的使用进行管理的现有法律法规体系是相互矛盾和含混不清的.一些现行的法律对生态系统的使用和转变问题做出了完全相反的规定.如果不对各项补贴权利重新定义,就不能确保对红树林进行合理、持续的管理.但这种权利的重新定义应考虑其生活与生态系统的健康状况密切相关的那些群体的需要. 相似文献