基于景观指数和空间自相关的吉林大安市景观格局动态研究

以松嫩平原西部盐碱化严重的典型区域大安市为研究对象,基于2000和2010年两个时期的土地利用和增强植被指数（EVI）数据,利用移动窗口法和局部空间自相关分析,研究大安市景观格局的变化。结果表明,大安市优势景观类型是农田、草地和盐碱地,2000年农田、草地和盐碱地分别占景观类型总面积的40.20%、19.09%和19.26%,2010年分别占景观类型总面积的41.69%、18.16%和19.94%。2000-2010年,农田和盐碱地面积增加,最大斑块指数增加,景观形状变得复杂,并且盐碱地的景观连通性增强,而草地的面积减少,最大斑块指数降低,景观形状变得复杂。大安市景观格局空间分布特征明显,优势度较高的景观类型分布的区域包括草地、农田和盐碱地,景观连通性强,景观破碎化程度和异质化程度低。而各种景观类型交错分布的区域景观破碎化程度较高,景观异质性较强。大安市2000和2010年EVI的局部Moran’s I分别为0.73和0.75,在空间分布上呈现出明显的空间自相关性。2000和2010年EVI呈高-高自相关的地区大多为农田,这些区域的植被覆盖较好,EVI呈低-低自相关的地区大多为盐碱地,植被覆盖较差。大安市不同景观类型的Moran’s I和斑块密度（PD）以及斑块形状指数（LSI）呈负相关关系,和最大斑块指数（LPI）以及蔓延度指数（CONTAG）呈正相关关系。移动窗口法和空间自相关法的结合分析,有助于了解大安市景观格局的空间变化特征及植被覆盖的空间聚集规律,从而为该地区生态环境保护提供依据。     

对几种环境质量综合指数评价方法的探讨

从《全国环境质量报告书》的编写出发,探讨了多种环境质量综合指数的应用。利用具体数据对各种方法进行了比较,进而提出在目前报告书中宜采用最大值法和算术平均法相结合的方法来对全国环境质量进行评价,并结合国外环境评价方法的发展趋势对未来报告书的评价模式提出了建议。     

温榆河水环境质量与浮游植物群落结构的时空变化及其相互关系

温榆河是北京市重要的生态廊道.本研究基于历史文献资料和现场调查,比较分析了2006、2011和2018年温榆河水环境质量与浮游植物群落结构的时空变化,探讨了浮游植物群落变化与水温T、溶解氧DO、pH和营养盐之间的相互关系.结果表明,温榆河水环境质量总体好转,经历了重度污染→污染遏制→水质改善过程,水污染物已从NH₄⁺-N为主转向TN为主.NH₄⁺-N、TN的平均浓度和平均超标倍数从2011年的15. 52～19. 16 mg·L^-1、9. 34～8. 58倍和20. 21～19. 58 mg·L^-1、12. 47～8. 79倍降低到2018年的1. 93～2. 66 mg·L^-1、0. 29～0. 33倍和5. 66～6. 79 mg·L^-1、2. 77～2. 39倍,并且温榆河和支流清河的DO和NH₄⁺-N浓度已基本达到水功能区划目标.与水质改善过程相对应,浮游植...     

包头市生态监测指标体系研究初探

随着全球生态问题的不断涌现，生态保护的呼声日益高涨，要想顺应这一形势的要求，实现切实有效的生态保护，首先必须对生态破坏状况要有一个准确的把握，而生态监测是全面掌握生态状况的有效手段和唯一 途径。目前国内的生态监测工作缺乏统一的标准，国家尚未制定技术规范。本研究针对包头市的特点，以景观生态学理论为依据，将包头市划分为五大景观生态系统，根据其各自特点，突出主要生态问题，制定了相应的生态监测指标体系，从而为生态监测工作的开展打下了坚实的基础。     

酚类化合物的QSAR研究

直接应用化合物的分子结构式产生的结构描述参量研究了４５个酚类化合物的麻醉毒性和分子结构之间的相关性。用多元回归分析和神经网络法建立了相应的数学模型，并用其预测了５个酚类化合物的麻醉毒性。结果表明，所提取的结构参量较好地反映这类化合物的结构特性，而用神经网络法所得结果优于多元回归分析结果。     

Comparing urban air quality in Europe in real time a review of existing air quality indices and the proposal of a common alternative

The EU directives on air quality force member states to inform the public on the status of the ambient air quality. The Internet is commonly used for this purpose and often air quality is being presented as an index ranging from good to bad. A review of existing websites and air quality indices shows that the way air quality is interpreted differs considerably. The paper presents a new air quality index. The index is part of a project to develop a website dedicated to comparing air quality in European cities. The common air quality index (CAQI) is not aimed at replacing existing local indices. The CAQI is a set of two indices: one for roadside monitoring sites and one for average city background conditions. Differentiating between roadside and general city conditions is a first step in assuring consistence in the parameters that are being compared.     

生物多样性研究进展

生物多样性是自然资源中的一个重要组成部分。在最近的40年内,生物多样性的研究发展很迅速,有关多样性的测定方法已形成了数十个数学模型和多样性指数。生物多样性的功能也研究得比较多,生物多样性的保护技术也已逐渐系统化,并开始了持续利用和合理开发的研究。     

Analysis of the effects of zinc pollution on the macro-invertebrate populations of the Afon Crafnant,North Wales

The study of the input draining from mine-waste into the Afon Crafnant, N. Wales, revealed that the most significant pollutant was zinc. The concentrations of zinc were monitored during 1978 and 1979, and spot samples were concentrated and analysed for lead, copper, cadmium, iron, cobalt, manganese and nickel. Analysis was by flame atomic absorption specto-scopy. The total zinc concentration of the input was about 4 mg Zn/l which was diluted by the Afon Crafnant to give mean annual concentrations of 213 g Zn/l and 146 g Zn/l for 1978 and 1979 respectively at a site 60 metres downstream of the input. The numbers of individuals and number of taxa in the macro-invertebrate community were reduced at these concentrations. The taxa affected werePhagocata vitta,Erpobdella octoculata, Oligochaeta,Ithytrichia lamellaris, Simuliidae,Ancylus fluviatilis andRithrogena semicolorata. Several commonly used diversity indices failed to show differences between the macro- invertebrate communities at the affected and control sites whereas a modified version of Chandler's Biotic Score (detailed in this paper) revealed both the acute effects at higher concentrations and the chronic effects at lower concentrations.     

基于概率神经网络的污泥堆肥腐熟度的综合判别

由于污泥堆肥过程中各组分间相互影响和制约,污泥腐熟程度的判别系统呈现模糊性,使得传统评价方法对该判别系统很难正确认识。文章根据污泥堆肥的具体情况,提出了以含水率、挥发固体、粪大肠菌值、发芽指数作为腐熟程度的判别指标体系,并基于概率神经网络建立污泥堆肥腐熟程度的综合判别模型,然后用该模型判别上海市某污水厂污泥快速好氧堆肥工艺污泥堆肥样品的腐熟程度。结果表明:①将污泥堆肥的含水率、有机质、粪大肠菌值和种子发芽指数作为判别指标,可以判别污泥堆肥腐熟程度;②概率神经网络可以建立判别指标与稳定化程度等级之间复杂的非线性关系,为腐熟度的判别提供一种通用的模式,且判别结果比较合理。     

Assessment of the Sustainability of Bushmeat Hunting Based on Dynamic Bioeconomic Models

Abstract:  Open-access hunting is a dynamic system in which individual hunters respond to changes in system variables such as costs of hunting and prices obtained for their catch. Sustainability indices used by conservationists ignore these human processes and focus only on the biological sustainability of current offtake levels. This focus implicitly assumes that offtake is constant, says little about the actual sustainability of the system, and fails to provide any basis for predicting the impact of most feasible management interventions. A bioeconomic approach overcomes these limitations by explicitly integrating both the biological and human components of the system. We present a graphical representation of a simple bioeconomic model of bushmeat hunting and use it to demonstrate the importance of considering system dynamics when assessing sustainability. Our results show that commonly used static sustainability indices are often misleading. The best method to assess hunting sustainability is situation dependent, but characterizing supply and demand curves, even crudely, has greater potential than current approaches to provide robust predictions in the medium term.