西南喀斯特环境移民示范区柑橘园水土流失及土壤水分变化

对西南喀斯特地区2种不同建园方式柑橘园水土流失情况进行连续3a的定位监测,并研究了4种类型柑橘园土壤含水量的年动态变化。结果表明,2种不同建园方式柑橘园的土壤流失量逐年减少,坡地柑橘园的年径流系数大于梯地柑橘园;不同类型柑橘园土壤含水量与土壤层次、建园方式及柑橘园成土母质有关;柑橘园土壤含水量与月降雨量呈正相关,应在不同月份对柑橘园采取不同水分调控措施。     

思茅市三家村农户庭园系统的能流和经济流研究

通过对三家村 6种农户庭园模式进行能流和经济流的系统研究 ,得出三家村 6种农户庭园系统的能量投入为 (98.4 8～ 174 .4 5 )× 10 10 J·hm-2 ,能量产出为 (10 1.6 6～ 15 8.5 2 )× 10 10 J·hm-2 ,能量产投比为(0 .88～ 1.4 1)∶1,并且以种植业为主的农户庭园 (模式Ⅰ、Ⅱ )的能量产投比高于以养殖业和副业为主的农户庭园系统 (模式Ⅵ、Ⅶ、Ⅸ ) ;三家村 6种农户庭园模式的经济产投比为 (1.0 0～ 1.35 )∶1,其高低次序是Ⅵ >Ⅶ >Ⅰ >Ⅱ >Ⅴ >Ⅸ ,6种农户庭园模式的经济产出为 2 32 7.9～ 980 3.4元。因此 ,三家村农户庭园系统是一个能量和经济的高投入高产出的人工生态系统     

扬州市生态旅游发展战略的研究

分析扬州市旅游业发展的优势和劣势，论述并评价扬州市主要的生态旅游资源，进行扬州市生态旅游发展的功能分区与项目策划，提出实施扬州市生态旅游发展战略的对策及措施。     

微生物资源的开发利用与农业可持续发展

对微生物资源在农业可持续发展中的作用及其合理开发利用进行了阐述和总结。认为微生物作为一种宝贵的资源,它与农业可持续发展的关系十分密切,它在土壤肥力的提高与保持、营养元素的转化、环境净化与生态系统的平衡等方面起着极其重要的作用。因此,加强以微生物肥料、微生物农药、微生物食品、微生物饲料、环境激素和环境工程微生物等为核心的农业清洁生产技术的研究与开发利用将具有广阔的应用前景。微生物农业即所谓的"白色农业"将成为未来农业可持续发展的重要方向之一。     

利用年限对农牧交错带退耕还草地土壤物理性质的影响

在农牧交错带以小麦为对照,比较研究不同利用年限对退耕还草种植的老芒麦草地土壤物理性质的影响。结果表明,随利用年限增加,在0~30cm范围内,老芒麦草地土壤体积质量呈现先降低后增加,土壤含水量、孔隙度呈现先增加后降低的趋势。利用第2年的老芒麦草地土壤体积质量最小、孔隙度最大,利用第3年的老芒麦草地土壤含水量最大。利用年限对0~120min内的老芒麦草地土壤渗透性影响不大。不同利用年限老芒麦草地首30min渗透率大小顺序为:第2年>第1年>第3年>第4年,利用第2年的老芒麦草地通过渗透截留降水的能力较强。一个生长季后,不同利用年限的老芒麦草地土壤含水量、孔隙度和体积质量分别比小麦地平均提高3.86%、1.53%和降低6.07%。     

Effect of Pb,Cd and Cu on survival and development of Culex quinquefasciatus (Diptera: Culicidae)

ABSTRACT

The present research aimed to determine the lowest levels of three heavy metals (Pb, Cd and Cu) to which the larvae of Southern House Mosquito, Culex quinquefasciatus are susceptible in water. The study also aimed to investigate the effects of these heavy metals on the development of Cx. quinquefasciatus at concentrations set by Pakistan Environmental Protection Agency (Pak-EPA) as permissible levels for liquid industrial effluents. The 2nd instar larvae of Cx. quinquefasciatus were exposed to different concentrations of Pb, Cd and Cu and their effects on oviposition preference, egg hatching rate and larval development were studied. The LC₅₀ values of Pb, Cd and Cu were 12.6, 6.3 and 2.6?ppm, respectively. Gravid female mosquito adults deposited a significantly lower number of egg rafts in containers containing 0.50?ppm Pb or 1.0?ppm Cu in water. Each of the heavy metals in water resulted in significantly (p?<?0.05) lower egg hatching rate, prolonged time to pupation, lower pupation rate, prolonged time to adult emergence, lower adult emergence rate and higher female to male ratio. It is concluded that the 2nd instar larvae of Cx. quinquefasciatus are susceptible to Pak-EPA permissible levels of Pb, Cd and Cu in municipal and liquid industrial effluents.     

Impact of canal development on intertidal microalgal productivity: Comparative assessment of Patterson Lakes and Ralphs Bay,South East Australia

We assessed the potential impact of a proposed canal development in an estuarine sandflat at Ralphs Bay, Tasmania on intertidal microalgal productivity and species composition, by comparing it over summer and winter seasons with a well- established (30 year old) canal estate at Patterson Lakes, Victoria. Pulse amplitude modulation (PAM) fluorometry was used to generate a relative measure of photosynthetic performance, which combined with microalgal chlorophyll biomass and irradiance provides an assessment of potential primary productivity. We present a sophisticated mathematical model for calculating benthic microalgal production and the contribution to total primary production, taking into account sediment light attenuation as estimated from sediment grain size. Ralphs Bay had a total productive microalgal biomass of 44 mg chlorophyll a m⁻² which was six times higher than Patterson Lakes, while the relative productivity of Ralphs Bay was four times greater compared to Patterson Lakes where productivity was virtually absent in the subtidal zone of the canal waterway. Ralphs Bay exhibited a more or less homogeneous spatial distribution of microphytobenthos biomass but this was subject to some seasonal variation in species composition, abundance and productivity. By contrast, at Patterson Lakes biomass distribution, diversity and productivity was highly spatially variable in the canal system in both seasons. Patterson Lakes exhibited 60% lower microphytobenthos species richness than Ralphs Bay but little variation in species composition occurred between seasons in the canal estate. This suggests that the dominant diatom species in Patterson Lakes, Pinnularia yarrensis, Gyrosigma balticum and Pleurosigma salinarum, are well adapted to the disturbance regime within the canal estate. The proposed canal development at Ralphs Bay is estimated to cause a decrease in microalgal productivity by both reducing available marine substrate (66% reduction) and replacing productive intertidal phytobenthic habitat with nonproductive canal substrate. These combine to cause a decline in productivity of 92% with significant flow-on effects predicted for higher trophic levels such as migratory wading birds.     

生态安全研究进展

在广泛调研现有生态安全研究成果基础上 ,从生态安全的概念、特性、国内外研究现状、研究意义和研究方法方面 ,对生态安全研究进行了评述     

我国城市垂直绿化现状与垂直绿化新技术

虽然我国各城市开展城市垂直绿化推广工作，取得了不少成效，但是依然存在着垂直绿化技术和植物种类单一、效果有待改善等问题。近年来，国内外出现了不少新的垂直绿化技术，若能借鉴、选择性地进行应用，对我国城市垂直绿化工作必定起促进作用。介绍了几种较新的垂直绿化技术，以供参考。