重庆丘陵山区石灰性黄壤呼吸特征及影响因素

采用静态暗箱一二氧化碳红外分析仪法研究了重庆丘陵山区石灰性黄壤土壤呼吸特征及影响因素.结果表明,土壤呼吸速率呈现季节性动态变化特征,冬季较低,夏季较高,与地温的季节动态变化基本一致;土壤呼吸与地温之间呈指数关系,其中与5 cm地温的相关性最好;不同土层、不同处理的Q10值不同,变化范围为1.67～2.69.不同田间管理措施对土壤呼吸速率有明显影响,表现为施肥土壤＞未施肥处理,种植作物土壤＞裸地;化肥使种植作物土壤的年平均呼吸速率增加70.8%,化肥、粪肥共同作用增加129%;与裸地相比,单种作物不施肥不能显著增加土壤CO2排放.裸地春、秋、冬季的土壤呼吸速率与土壤水分呈直线关系,决定系数R2=0.414,P＜0.01.在夏季,种植作物未施肥和施化肥处理两者也呈直线关系,R2分别为0.5361和0.4261(P＜0.05),其他季节两者未表现出明显的规律性.     

化学与工程措施强化重金属污染土壤植物修复

作为植物修复的辅助措施,化学方法强化与工程技术强化能有效提高土壤重金属污染的修复效率.综述了化学方法与工程技术强化重金属污染土壤植物修复的研究进展,重点讨论了络合强化技术和基因工程技术用于强化植物修复的基本原理、相关化学物质或基因、主要技术步骤、存在问题以及解决方法,并在此基础上提出了今后研究的展望.     

苯乙烯对几种海洋生物的急性毒性效应

在封闭静水式条件下,苯乙烯对小新月菱形藻和扁藻的96 hEC50分别为8.96 mg/L和5.94 mg/L.苯乙烯对甲壳动物和鱼类的实验采取开放静水式方法.中国对虾仔虾和中华绒螯蟹幼蟹的96 hLC50 分别为7.96 mg/L和72.27 mg/L,牙鲆的96 h LC50为18.55 mg/L.按新化学物质危害评估导则中的分级标准,苯乙烯对两种实验藻和中国对虾的毒性属高毒性,对中华绒螯蟹和牙鲆具有中毒性.计算出苯乙烯的无影响阈值(ENEV)为0.594 mg/L,可以为制定苯乙烯的水生生物安全阈值提供参考.     

飞机气候试验

现代战争要求飞机具有全天候作战能力。飞机气候试验是在进行复杂气象条件试飞前需要完成的气候环境试验,用以验证飞机和地面保障设备的气候环境适应性设计,保证飞行安全。结合国内外气候试验发展情况,介绍了飞机气候试验的目的、重要性、试验内容、试验管理及工作程序等。     

景观生态学在农业园区规划环评中的应用

根据西南一农业园区规划前后土地利用变化的结果,借助地理信息系统技术,运用景观生态学基本理论分析了农业园区规划前后景观格局变化,主要结果为:规划后区域优势景观类型仍为耕地,但各类生境斑块的生态系统能力有所下降,农村居民点的集中建设有利于景观破碎化程度减轻,但路网的建设又加重了景观破碎化。在农业园区的规划中,须考虑林地和自然保留地这两类土地类型的合理分布,特别是现有生态系统较好的斑块,对评价区生物多样性的保持具有重大意义。     

Guidelines for Riparian Vegetative Shade Restoration Based Upon a Theoretical Shaded‐Stream Model1

Abstract: Guidelines for riparian vegetative shade restoration were developed using a theoretical model of total daily radiation received by a shaded stream. The model assumed stream shading by nontransmitting, vertical or overhanging, solid vegetation planes in infinitely long reaches. Radiation components considered in the model were direct beam shortwave on the stream centerline, diffuse atmospheric shortwave, shortwave reflected by vegetation, atmospheric longwave, and longwave emitted by vegetation. Potential or extraterrestrial shortwave irradiation theory was used to compute beam shortwave radiation received at the stream centerline, and view factor theory was used to compute diffuse radiation exchange among stream, vegetation, and atmospheric planes. Model shade effects under clear skies were dominated by reductions in receipt of direct beam shortwave radiation. Model shade effects with cloudy skies were dominated by the “view factor effect” or the decreases in diffuse shortwave and longwave radiation from the atmosphere balanced against increases in longwave radiation from vegetation. Model shade effects on shortwave radiation reflected by vegetation were found to be negligible. The model was used to determine the vegetation height (H) to stream width (W) ratios needed to achieve 50, 75, and 90 % shade restoration for mid‐latitude conditions on clear and cloudy days. Ratios of vegetation height to stream width, for dense nontransmitting vegetation, generally ranged from 1.4 to 2.3 for 75% shade restoration at a mid‐latitude site (40°N). The model was used to show H/W needed for E‐W vs. N‐S stream azimuths, varying stream latitudes between 30° and 50°N, channels with overhanging vegetation, channels undergoing width changes, as well as the limits to shade restoration on very wide channels.     

广西陆上风电场开发存在的环境问题及对策研究

广西从保证能源安全,减少污染物排放,保护环境,满足低碳经济社会发展对能源的需要,将风电项目作为新能源项目重点推进.广西陆上风电场大部分位于水源涵养和生物多样性保护生态功能区、水土流失重点防治区等敏感区,通过分析目前风电规划、建设在选址、生态环境破坏方面存在的问题,对广西陆上风电场开发建设、环境管理提出相关建议.建议对广西风能资源开发所取得环境经济效益进行全面评估,指导推进广西陆上风电场的开发建设.     

Effects of Artificial Roosts for Frugivorous Bats on Seed Dispersal in a Neotropical Forest Pasture Mosaic

Abstract:  In the Neotropics ongoing deforestation is producing open and heavily fragmented landscapes dominated by agriculture, mostly plantations and cattle pastures. After some time agriculture often becomes uneconomical and land is abandoned. Subsequent habitat regeneration may be slow because seed inputs are restricted by a lack of incentives—such as suitable roost sites—for seed dispersers to enter deforested areas. Increasing environmental awareness has fostered growing efforts to promote reforestation. Practical and cost-efficient methods for kick-starting forest regeneration are, however, lacking. We investigated whether artificial bat roosts for frugivorous bat species can attract these key seed dispersers to deforested areas, thereby increasing seed rain. We installed artificial bat roosts in a forest-pasture mosaic in the Costa Rican Atlantic lowlands and monitored bat colonization and seed dispersal. Colonization occurred within a few weeks of installation, and 10 species of bats occupied the artificial roosts. Five species of frugivorous or nectarivorous bats colonized artificial roosts permanently in both primary habitat and in deforested areas, in numbers similar to those found in natural roosts. Seed input around artificial roosts increased significantly. Sixty-nine different seed types, mostly of early-successional plant species, were transported by bats to artificial roosts in disturbed habitats. The installation of artificial bat roosts thus successfully attracted frugivorous bats and increased seed inputs into degraded sites. This method is likely to speed up early-vegetation succession, which in turn will attract additional seed dispersers, such as birds, and provide a microhabitat for seeds of mid- and late-successional plants. As well as supporting natural forest regeneration and bat conservation, this cost-efficient method can also increase environmental awareness among landowners.     

黄河下游历史泥沙灾害的宏观特征及其与流域因素及人类活动的关系(Ⅰ)──历史气候及植被因素的影响

以历史上黄河下游的决溢频率为泥沙灾害的代用指标；研究了黄河下游历史泥沙灾害的宏观特征．研 究表明，气候因素对黄河下游决溢频率有深远的影响．隋唐以前，天然植被尚未遭到显著破坏，当湿润指标 增大时，有利于植被的生长，故黄河下游决溢频率减小．１０世纪以后，二者的关系与此相反，当湿润指标增 大时，决溢频率也增大，反之亦然．每世纪大旱年颁次与每世纪决溢频次之间呈明显正相关，说明目前受到 各方面广泛关注的黄河下游“小水大灾”现象，在历史上已经存在．干旱时期中，河槽萎缩，一旦大水来 临，很容易发生决溢．以华山松树木年轮指数为气温的代用指标，研究了气温变化与决溢频率变化的关系， 结果表明，在５０ａ的尺度上，当气温降低时，决溢频率增大，反之亦然．人类活动是影响黄河下游泥沙灾害 的重要因素．     

试论矿山环评中的生态恢复评价问题

矿山生态恢复是矿山环保对策中的一项技术较强的措施之一，它既有防治水土流失的功能，又有降解有毒污染的功能，并能产生较好的经济效益。但没有科学依据而盲目进行生态恢复，就有可能对环境和人类带来风险，为减少风险，在矿山开发前的环境影响评价中，就应对生态恢复这一措施进行评价，提出合理的恢复模式，为决策部门提供科学依据。