基于高分辨率遥感影像的城市土地利用景观格局分析

以IKONOS卫星遥感影像为基础数据源,在GIS技术的支持下,获取了泸州市区的土地利用类型。借鉴景观生态学的基本原理和方法,基于Fragstats 3.3软件,用景观格局指数定量分析了泸州市区土地利用景观格局的特征。分析结果表明,泸州市区土地利用景观类型丰富,景观多样性程渡高,景观类型均匀程度也较高,但优势景观类型不明显;由于人类干扰程度较大,土地利用景观破碎,稳定性较差。     

Experimental exposure to cadmium affects metallothionein-like protein levels but not survival and growth in wolf spiders from polluted and reference populations

Both local adaptation and acclimation in tolerance mechanisms may allow populations to persist under metal pollution. However, both mechanisms are presumed to incur (energetic) costs and to trade-off with other life-history traits. To test this hypothesis, we exposed Pardosa saltans (Lycosidae) spiderlings originating from metal-polluted and unpolluted sites to a controlled cadmium (Cd) treatment, and compared contents of metal-binding metallothionein-like proteins (MTLPs), internal metal concentrations, and individual survival and growth rates with a reference treatment. While increased MTLP concentrations in offspring originating from both polluted and unpolluted populations upon exposure indicates a plastic tolerance mechanism, survival and growth rates remain largely unaffected, independent of the population of origin. However, MTLP and Cd concentrations were not significantly correlated. We suggest that MTLP production may be an important mechanism enabling P. saltans populations to persist in ecosystems polluted with heavy metals above a certain level.     

Sustainable land-use planning: revitalising a flood prone office park

This paper describes an applied research project that used a sustainable land-use planning approach to examine flood hazard mitigation alternatives in a 536-acre developed office park complex. A watershed-wide assessment including floodplain remapping and modelling of low-impact and large stormwater improvements throughout the upper watershed revealed limited impact on reducing flooding downstream in the environs of the office park during large storms. Thus emphasis had to be given to recommending retroactive sustainable land-use development actions such as relocating buildings and roadways out of the 100-year floodplain, which involves creating a mixed-use overlay district on high elevations, and restoring the floodplain.     

基于集对分析的江苏省土地利用协调性研究

从协调性的研究现状来看,现有研究的基础性工作缺失,且受到“均衡发展”思想束缚、不能很好地描述不确定性问题,而基于集对分析方法的协调性研究可以很好地解决以上问题.以江苏省土地利用系统为研究对象,首先运用典型相关分析对子系统之间的相关性进行验证;其次,引入集对分析思想,对土地利用的效益协调性和消耗协调性进行了评价.结果显示:土地利用变化子系统同土地利用各效益子系统之间表现出较为显著的相关性;土地利用的效益协调度大多处于较为协调状态.其内部结构表明,虽然当前政府在促进经济社会发展的同时更加注重对生态环境的保护,但并没有从根本上解决经济发展和生态环境恶化之间的矛盾;消耗协调度变动幅度相对较小,土地利用变化同土地利用效益之间基本呈现“均衡”发展态势.政府逐渐认识到用地规模的过度扩张所带来的各种负面影响,追逐用地效益的提升成为发展的主线.与以往研究结论不同的是,效益协调度和消耗协调度均没有表现出显著的持续增长态势.     

三江平原不同土地利用方式下土壤磷形态的变化

利用Hedley磷(P)分级方法,比较研究三江平原不同土地利用方式（天然湿地、旱田、水田、弃耕地、人工林地）下土壤P形态变化.结果表明,不同土地利用方式下土壤总磷（TP）含量表现为：湿地>林地>旱田>弃耕地>水田.农田土壤的无机磷（TP_i）占TP比重显著高于湿地,有机磷比重则为湿地高于农田,且水田土壤有机磷（TP_o）比重最小,弃耕地和林地之间差别很小.不同土地利用方式土壤活性无机磷含量差异较小,Resin-P含量约为32～36.3 mg·kg^-1,NaHCO₃-P_i含量为33.77～50.42 mg·kg^-1;农田土壤NaOH-P_i和C.HCl-P_i含量高于湿地土壤,特别是水田中NaOH-P_i达152.4 mg·kg^-1,湿地土壤中D.HCl-P_i含量高于农田达84.3 mg·kg^-1,弃耕地和林地介于二者之间,表明弃耕后土壤P的恢复有向天然湿地的状况发展的趋势.开垦使湿地所有形态有机磷含量和比重都大幅下降,其稳定态有机磷C.HCl-P_o下降幅度最大,其在旱田和水田土壤中含量分别仅为湿地中的25.96%和19.26%;弃耕地有机磷含量比重均有增加,但是速度十分缓慢,湿地开垦后土壤P的恢复需要很长时间.不同土地利用方式下土壤P形态存在显著的差异.     

泉州湾沉积物柱状样中有机氯农药的垂直分布特征

用GC-ECD内标法测定了泉州湾沉积物柱样中有机氯农药的含量.通过研究有机氯农药在沉积物柱样中的垂直分布特征,探讨了有机氯农药在泉州湾的污染历史.该柱样中HCHs和DDTs的含量分别为(0.00～5.61)×10-9、(1.18～50.65)×10-9.研究表明该区沉积物未受到HCHs的明显污染,但已受到DDTs的轻微污染.有机氯农药的垂直变化基本反映了它在我国及福建的生产使用历史.在近年泉州湾仍有新的DDT输入.     

我国自然保护区的土地权属问题研究

建立自然保护区是开展自然保护工作的重要基础。自然保护区的建立首先面临的就是自然保护区的土地权属问题,即自然保护区的土地归谁所有,归谁使用等。本文首先介绍了我国自然保护区土地权属的现状,分析存在的问题,结合我国土地管理的历史背景,指出导致我国自然保护区土地权属不清的原因所在,并分析了土地权属不清所带来不良后果,如自然保护区内资源的过度开发利用、与周边社区纠纷不断等。最后,本文通过借鉴国外自然保护区土地权属管理的经验,结合我国土地权属管理的具体情况,提出解决我国自然保护区土地权属问题的途径。     

Gene flow and local adaptation in a sunfish-salamander system

There is increasing evidence that populations may not be well adapted to their local environments, and as a result, recent interest has focused on understanding factors that constrain adaptive evolution. This study presents data suggesting gene flow may constrain the ability of larvae of the streamside salamander Ambystoma barbouri to avoid predation by fish via escape behavior and life history tactics. Streamside salamander larvae face conflicting selection pressures in different streams. Some streams are ephemeral, where larvae should be active to feed, grow, and reach metamorphosis before stream drying. Other streams contain predatory fish, where larvae should be generally inactive to avoid predation. Previous work has shown that streamside salamander larvae exhibit ineffective antipredator behavior by having inappropriately high activity levels with fish, resulting in high predation in laboratory and field experiments. This study investigated the possibility that gene flow from larvae in ephemeral habitats may reduce the escape performance of larvae from populations with fish and alter their life history characteristics to increase their susceptibility to fish predation. I assayed escape behavior (speed, acceleration, and duration of escape) and life history characteristics (hatching date, size, stage) associated with predator avoidance among laboratory-reared larvae from four populations. As predicted, two populations (one with fish and the other fishless and ephemeral) connected by gene flow were not significantly different in almost all assays. In contrast, larvae from an isolated population with fish had significantly stronger escape behaviors and delayed hatching than both an isolated population that lacked a history of fish co-occurrence and the population with fish but gene flow from a fishless population. These results support theory suggesting that gene flow can constrain adaptive evolution. Received: 22 February 1999 / Received in revised form: 4 April 1999 / Accepted: 26 April 1999     

纵向岭谷区公路沿线土地利用变化与扩展效应

运用A RC I/NFO软件,对纵向岭谷区内典型公路沿线1km、2km、5km和20km缓冲带土地利用数据进行分析。通过土地利用转移矩阵、土地利用程度综合指数和扩展强度指数,研究了公路沿线土地变化及公路的扩展效应。研究表明:①各缓冲带内均存在林地向耕地和草地退化的现象;②研究区自然状况完好,林地与草地所占比例之和均超过土地总面积的80%,但存在一定的内部差异性;③景洪各缓冲带土地利用程度排序为La2k0m>La5km>La2km>La全区>La1km,保山土地开发利用程度高于景洪,排序情况La1km>La2km>La5km>La全区≈La2k0m;④公路的扩展效应与土地利用程度综合指数基本上是一致的,但扩展效应不显著。受地形地貌条件的限制,公路扩展效应的影响阈为公路周边1～5km。     

A Hierarchy of Groundwater Management, Land-Use, and Social Needs Integrated for Sustainable Resource Development

The pyramid of human needs developed by Abraham Maslow is based upon the presumption that until a person's lower level needs are fulfilled, higher level needs remain irrelevant. Groundwater and land-use management can likewise utilize such a hierarchy in integrating plans and operations with the needs of the society. Only once a region's population has fulfilled more basic concerns can higher-level groundwater and land-use management needs be effectively achieved. Attaining the ultimate goal of resource sustainability would certainly require considerable public backing, both for financial support and minimizing ambient pollution. For efficient water management to supply a society's water needs for future generations, sustainable groundwater management will require the full support of an educated society. The objective of the authors is to point out how essential it is to integrate operational strategies into regional hierarchies of needs applicable to groundwater management, land-use, and social planning. The situation of groundwater resources in Israel's Sharon Coastal aquifer region is taken as a case in point. Remedial groundwater activities have been undertaken in the management program for this aquifer. But it appears that maximal management efficiency cannot be achieved until the public's basic concerns are satisfactorily addressed and water resources planners reach consensus and a working partnership with the society in question. Operational measures must be clearly shown to benefit the region's population as regards their social, economic, and environmental concerns. This can only be achieved through public education, promoting awareness of the issuesbreak involved.