Active Adaptive Management for Conservation

Abstract:  Active adaptive management balances the requirements of management with the need to learn about the system being managed, which leads to better decisions. It is difficult to judge the benefit of management actions that accelerate information gain, relative to the benefit of making the best management decision given what is known at the time. We present a first step in developing methods to optimize management decisions that incorporate both uncertainty and learning via adaptive management. We assumed a manager can allocate effort to discrete units (e.g., areas for revegetation or animals for reintroduction), the outcome can be measured as success or failure (e.g., the revegetation in an area is successful or the animal survives and breeds), and the manager has two possible management options from which to choose. We further assumed that there is an annual budget that may be allocated to one or both of the two options and that the manager must decide on the allocation. We used Bayesian updating of the probability of success of the two options and stochastic dynamic programming to determine the optimal strategy over a specified number of years. The costs, level of certainty about the success of the two options, and the timeframe of management all influenced the optimal allocation of the annual budget. In addition, the choice of management objective had a large influence on the optimal decision. In a case study of Merri Creek, Melbourne, Australia, we applied the approach to determining revegetation strategies. Our approach can be used to determine how best to manage ecological systems in the face of uncertainty.     

南京住宅小区雨水回用方案技术经济分析

分析了南京城区雨水资源量和杂用水需求量的关系，通过示例，提出了住宅小区4种雨水回用方案，进行工程造价、雨水处理成本等方面的技术经济比较，结果方案3最优。     

Reconnaissance soil geochemical survey of Gibraltar

The extreme density of population of Gibraltar, situated at the southern tip of Spain, exerts considerable pressure on land use and thus future planning is of utmost importance. An initial reconnaissance soil geochemical survey of Gibraltar was based on 120 surface samples (0–15 cm) taken from a wide range of exposed, either bare soil or vegetated sites, to provide the optimum geographical distribution. The total elemental concentrations of 26 elements (Li, Na, K, Be, Mg, Ca, Sr, Ba, Al, La, Ti, V, Cr, Mo, Mn, Fe, Co, Ni, Cu, Ag, Zn, Cd, Pb, P, S, As) were determined by nitric/percholric acid digestion followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The reconnaissance data shows that the spatial distribution of various elements depended on previous and present land use. Most elements (Ca, Cr, Mg and Mn excluded) exhibited relatively high concentrations in civilian and natural soils. Trends have been established for many elements, and concentrations exceeding guideline values have been found in certain areas of Gibraltar. This reconnaissance of Gibraltar is at present being followed by a more detailed baseline geochemical survey, which will establish the extent and magnitude of the variations in major and trace elements in soils and dusts, assess the impact of industrial, commercial and urban development on the geochemical landscape and to make recommendations concerning sustainable development.     

岳阳市城市绿化树种的选择及配置模式研究

选择观赏价值高、抗逆性强、保健功能强、经济效益高同时具有丰富历史文化底蕴和地方特色的植物材料用于城市林业建设中,可显著提高城市园林绿化的科技含量和综合效益;在园林植物配置上,根据园林美学原则和功能性要求,进行混植、群植、丛植、对植和孤植等,在充分发挥树木的群体美和个体美的同时可显著提高配置模式的整体功能性．     

城市绿地系统景观生态规划探讨

从景观生态的角度对城市绿地系统进行规划探讨,能够为绿地系统规划布局提供科学的理论指导。在介绍了对绿地系统规划有重要指导意义的景观生态理论的基础上,以常州市新北区为例,进行实证研究,概括了其绿地现状并指出了其存在一系列问题,进而利用景观生态的基本原理,对本区域的绿地系统进行规划研究。将整个研究地区分成“区域层面、分区层面以及具体规划设计层面”3个尺度层面,并且在每个层面利用景观生态中相关原理分别进行研究,最终形成层次分明、在功能上相互补充、有机联系的绿地系统结构。     

城市热岛效应研究进展

作为现代城市气候主要特征之一的城市热岛效应有日渐严重的趋势。文章综述了城市热岛的生态环境效应、热岛的主要形成机制、时空分布特征等研究状况和发展趋势；基于当前城市热岛研究的现状，提出了未来城市热岛效应研究的方向及缓解城市热岛效应的有关对策。     

A Geochemical Survey of Topsoil in the City of Oslo, Norway

The city of Oslo is situated centrally in the Oslo-graben, which is a Permian rift basin consisting of different kinds of volcanic and sedimentary rocks. In the summer of 1998, approximately 300 samples of surface soil (2–3cm) were taken systematically, 1km^–2. The investigated area covers about 500km². Samples were dissolved in 7M HNO₃ and analysed for 29 elements with ICP-AES, mercury with cold-vapour technique (CV-AAS) and arsenic and cadmium with a graphite furnace (GF-AAS). A factor analysis is frequently used to identify relationships among sets of interrelated variables. To describe the covariant relationships among the elements, a factor analysis has been completed. The first factor contains the elements Sc, Fe, Li, Co, Al, Cr, Be, K, Ni, V, Mg, Y, Ba, Zr, Mn and As (listed with decreasing communality). These elements are typical for the minerals in the area and most of these elements have a near normal distribution. Sources for this factor are probably geological. The second factor contains Cd, Hg, P, Zn, Cu, Ba and Pb. They have a log-normal distribution. Road traffic is probably one of the sources contributing to this factor. In Norway studded tyres are used frequently in the winter season which results in large amounts of road dust. Leaded petrol has been a major source for Pb but is not in use any more. Wear and tear of tyres and brakes contribute also to this factor. Other sources contributing to this factor are probably industry, rubbish incineration, crematoria and release of some of these elements from structural material by fire. Factors 3, 4 and 6 with elements such as Ca, Na, La, Ti and Sr probably have geological sources. They are associated with minerals like amphiboles, pyroxenes and feldspars and some of the elements are from sea aerosols. Factor 5 contains Mn, Cd, Zn, As and Pb. Manganese may be derived from many different sources such as rock weathering, windblown dust, agriculture and traffic. Since As and Mn are placed in both factor 1 and 5 they probably have both geological and anthropogenic sources. Concentrations of the elements in the second factor are much higher in the central parts of Oslo, than in the rest of Oslo. The median value of Hg in the centre is 0.48mgkg^–1, which is 8 times higher than that in the rest of the city. Also, the other elements have much higher levels in the centre. The industrial district north-east of the centre also has high values. The distribution of arsenic is regular throughout the whole city, but has a slightly higher level in the centre. Norm values for contaminated land used by the Norwegian authorities are 2mg As kg^–1 and 25mg Cr kg^–1. Of 297 samples, 61% contain more than 25mg Cr kg^–1 and 79% more than 3mg As kg^–1, which is the detection limit of the analysis. These samples will therefore be regarded as contaminated. Factor analysis places these elements in the geological factor. The Norm value of zinc is 150mgkg^–1, and 40% of the samples contain more than this. The Norm value of lead is 150mgkg^–1, and 35% of the samples contain. Road traffic is probably the major source for these elements.     

湖南怀化地区96.7城市特大洪涝灾害成因分析

湖南省怀化地区地形以山地为主,该地区１９９６年７月发生了城市特大洪涝灾害,本文概述了该地区９６．７城市洪涝灾情,并以区域灾害系统论为指导,从孕灾环境、致害因子、承灾能力和人类活动的不利影响等方面,对这次灾害的成因进行了分析,认为其主要成因是：（１）易洪涝的山丘区环境;（２）９６．７降雨强度大、覆盖面广、持续时间长的异常雨情和高洪峰水位、流量的异常水情;（３）城市防洪标准低、水利水电工程防洪效益差和抗洪害意识不强等原因造成的城市防洪能力低;（４）砍伐森林、人为侵占河道和大型水库超常规蓄水等人类活动造成的不利影响。     

三峡工程淹没区文物古迹的价值评估(一)

文物价值是客观的,是文物本身固有的……依据三峡工程淹没区内文物古迹的特定地位,阐明了其文物价值,不应仅从现定文物级别下定论,还应立足于三峡地区本身的历史、文化及地理背景,从历史、艺术、科学等各方面去识别、评价。由于三峡工程淹没区内文物包罗万象,在对不同类型的文物进行价值评估时,其出发点、侧重点乃至整个价值评估体系,存在着一定的差异性,本文根据淹没区内建筑、石刻、古遗址以及古墓葬四大类分别进行了论述评价。     

我国城市地价评估模型及其空间分布规律研究

本文以城市地价产生地区差异的理论分析为依据,提出了城市地价的主要影响因素、因子,并以城市土地批租资料为基础运用逐步回归分析方法建立城市地价评估模型。根据模型估测了我国５１７个城市１９９２年的地价水平,最后分析了我国城市地价空间分布的规律及其未来走势展望。