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991.
污水处理厂出水中雌激素活性物质浓度与生态风险水平 总被引:6,自引:1,他引:5
再生水在环境和景观水体利用中,由微量有毒有害污染物,特别是内分泌干扰物引起的长期生态风险备受关注. 以再生水生态风险控制为目的,对城市污水处理厂出水(再生水)中雌激素活性物质浓度分布情况进行了研究,归纳了8种雌激素活性物质的出水浓度水平,比较分析了各物质的雌激素活性和生态风险. 结果表明:8种物质的质量浓度分布在ng/L~μg/L,其中ρ(类固醇)最低,为nd~50 ng/L;ρ(酚类)及ρ(酞酸酯类)主要在μg/L水平,个别高达40 μg/L. 雌激素活性分析和生态风险评价结果表明,污水处理厂出水(再生水)中3类雌激素活性物质的雌激素活性和生态风险顺序均为类固醇物质>酚类物质>酞酸酯类物质. 城市污水再生处理厂应优先控制乙炔基雌二醇(EE2)、雌酮(E1)和雌三醇(E3)等3种雌激素活性物质. 相似文献
992.
993.
Hong Li Mijail Arias Anouk Blauw Arthur E. Mynett Steef Peters 《Ecological modelling》2010,221(20):2435-2446
Physically based numerical modelling follows from the basic understanding of the underlying mechanisms and is often represented by a set of (partial differential) equations. It is one of the main approaches in population dynamics modelling. The emphasis of the model introduced in this paper is on the simulation of short-term spatial and temporal dynamics of harmful algal bloom (HAB) events. Total suspended matter (TSM) concentration is one of the dominant factors for harmful algal bloom (HAB) prediction in North Sea. However, the modelling of suspended matter contains a high degree of uncertainty in this area. Therefore, this research aims to achieve a better estimation for the short-term prediction of harmful algal bloom development in both space and time by using spatially distributed TSM retrieved from remotely sensed images as physically based model inputs. In order to supply complete spatially covered datasets for the physically based model instrument: generic ecological model (GEM), this research retrieves TSM information from MERIS images by means of proper estimation techniques including biharmonic splines and self-learning cellular automata. A better estimation of HAB spatial pattern development is achieved by adding spatially distributed TSM data as inputs to original GEM model, and it proved that chlorophyll-a concentration in this area is very sensitive to TSM concentration. 相似文献
994.
Structural modifications to landscapes affect the ability of organisms to access different habitat patches. There exist, however, very few general methods by which to relate modifications to expectations of effects, and even fewer that enable understanding of how multiple modifications may interact. In the absence of any guiding principles, ecologists have assumed that interactions will result in complex landscape-scale effects. One way of understanding such effects is through rendering a landscape as a graph or network, among the simplest of which are dendritic networks typified by stream systems. Yet even for stream networks, there are no known general principles concerning the nature of interactions between multiple modifications. We developed a model to describe the ability of fish to access and use different habitat patches within dendritic networks. We used mathematical and numerical analyses of the model to investigate how the habitat value of a network is affected by changes in connectivity and habitat quality, and then to examine interactions between multiple modifications. Rather than showing complex interactions, our analytic and simulation-based results show that the combined effect of multiple modifications approximately equals the sum of individually predicted effects. Dendritic networks thus appear to respond far more simply to multiple modifications than has previously been assumed. These results have implications for stream management planning, and offer a firm foundation from which to better understand population processes within dendritic networks. 相似文献
995.
JOCELYN G. MUELLER ISSOUFOU HASSANE BIL ASSANOU† IRO DAN GUIMBO‡ ASTIER M. ALMEDOM§ 《Conservation biology》2010,24(1):140-150
Abstract: There is a pressing need to find both locally and globally relevant tools to measure and compare biodiversity patterns. Traditional ecological knowledge (TEK) is important to biodiversity monitoring, but has a contested role in preliminary biodiversity assessments. We examined rapid participatory rural appraisal (rPRA) (a tool commonly used for local needs assessments) as an alternative to surveys of vascular plants conducted by people with local knowledge. We used rPRA to determine the local-knowledge consensus on the average richness, diversity, and height of local grasses and trees in three habitats surrounding Boumba, Niger, bordering Park-W. We then conducted our own vascular plant surveys to collect information on plant richness, abundance, and structure. Using a qualitative ranking, we compared TEK-based assessments of diversity patterns with our survey-based assessments. The TEK-based assessments matched survey-based assessments on measures of height and density for grasses and trees and tree richness. The two assessments correlated poorly on herb richness and Simpson's D value for both trees and grasses. Plant life form and gender of the participant affected the way diversity patterns were described, which highlights the usefulness of TEK in explaining local realities and indicates limitations of using TEK as a large-scale assessment tool. Our results demonstrate that rPRA can serve to combine local-knowledge inquiry with scientific study at a cost lower than vascular plant surveys and demonstrates a useful blunt tool for preliminary biodiversity assessment. 相似文献
996.
Bayesian Networks and Adaptive Management of Wildlife Habitat 总被引:1,自引:0,他引:1
Abstract: Adaptive management is an iterative process of gathering new knowledge regarding a system's behavior and monitoring the ecological consequences of management actions to improve management decisions. Although the concept originated in the 1970s, it is rarely actively incorporated into ecological restoration. Bayesian networks (BNs) are emerging as efficient ecological decision‐support tools well suited to adaptive management, but examples of their application in this capacity are few. We developed a BN within an adaptive‐management framework that focuses on managing the effects of feral grazing and prescribed burning regimes on avian diversity within woodlands of subtropical eastern Australia. We constructed the BN with baseline data to predict bird abundance as a function of habitat structure, grazing pressure, and prescribed burning. Results of sensitivity analyses suggested that grazing pressure increased the abundance of aggressive honeyeaters, which in turn had a strong negative effect on small passerines. Management interventions to reduce pressure of feral grazing and prescribed burning were then conducted, after which we collected a second set of field data to test the response of small passerines to these measures. We used these data, which incorporated ecological changes that may have resulted from the management interventions, to validate and update the BN. The network predictions of small passerine abundance under the new habitat and management conditions were very accurate. The updated BN concluded the first iteration of adaptive management and will be used in planning the next round of management interventions. The unique belief‐updating feature of BNs provides land managers with the flexibility to predict outcomes and evaluate the effectiveness of management interventions. 相似文献
997.
西安市生态文明建设评价及预测 总被引:2,自引:0,他引:2
根据生态文明的涵义和生态市建设的总体思路,提出了生态文明建设3(系统层、子系统层、单项指标层)×3(经济发展,社会进步,环境保护)评价体系,其中包括25个单项指标。对西安市1998-2007年生态文明建设进行了定量评价研究,结果表明西安市生态文明建设处于整体上升的趋势;在此基础上,应用自回归预测模型对西安市经济、社会、环境和生态文明建设发展进行了预测,为西安市全面协调发展提供参考借鉴。 相似文献
998.
浅谈城市绿化建设 总被引:2,自引:0,他引:2
范适 《湖南环境生物职业技术学院学报》2010,16(2):5-8
城市绿化是改善城市生态环境,提升城市形象,提高城市居民生活质量的有效途径之一.笔者提出了城市绿化的概念和内涵,提出了城市绿化必须坚持的三个原则:生态原则、坚持景观效应、坚持经济原则,分析了当前我国城市绿化存在的主要问题,并提出了改进的思路和措施.参10. 相似文献
999.
间伐对生态公益林冠层结构及土壤养分的影响 总被引:1,自引:0,他引:1
为定量分析上海城郊生态公益林间伐后林分冠层结构变化及对林下环境的影响,2009年7月采用TRAC植物冠层分析仪研究了香樟(Cinnamomum camphora)、杜英(Elaeocarpus sylvestris)和栾树(Koelreuteria paniculata)3种生态公益林间伐2年后林分冠层结构参数,设置临时样方调查各林分林下植物分布及生物量,测定了土壤N、P、K和有机质的变化。结果表明:间伐后3种林分的LAI、丛生指数和平均接触次数均降低,而间隙分数增大。间伐增加了林分间隙和LAI的空间异质性,间伐后3个树种LAI变异系数增加了19%~45%。轻度间伐后香樟、杜英和栾树林下PPFD(Photosynthetic Photon Flux Density)分别是未间伐林分的1.6、7和2.1倍,重度间伐香樟林内PPFD增大了8.9倍。间伐后林下植物种类、总盖度和干生物量随林下PPFD增加呈增大趋势。除全P和全K含量没有变化外,林地土壤全N、速效K、速效P和有机质含量均比未间伐林地有不同程度降低,但轻度间伐杜英林地速效养分消耗显著高于香樟和栾树林分。因此,研究区生态公益林结构调控需根据树种特性和林下环境变化,确定适宜的发展模式,提高公益林的综合效益。 相似文献
1000.
基于水土流失的景观格局分析方法 总被引:3,自引:0,他引:3
景观格局和生态过程是景观生态学研究的重要内容,但是很多研究只重视景观格局的研究,而忽略了生态过程的研究。文章针对水土流失这一重要生态过程,提出了基于水土流失过程的景观坡度指数和景观空间负荷对比指数,并对黄土高原泾河流域15个子流域的景观格局进行了分析,认为泾河流北部各子流域主要以水土流失的"源"景观为主,景观坡度指数大,空间负荷指数小,水土流失风险大;流域南部各子流域上游以"汇"景观为主,坡度指数大,中下游以"源"景观为主,景观空间分布不均衡,存在一定的水土流失风险;流域东部局部子流域主要以水土流失的"汇"景观为主,"源"景观相对较小,"源"-"汇"景观空间分布均衡,水土流失风险小。 相似文献