Effects of cage fish culture on water quality and selected biological communities in northern Lake Victoria, Uganda

Growing of fish in cages is currently practiced in Uganda and was first introduced in northern Lake Victoria in 2010. An environment monitoring study was undertaken at Source of the Nile, a private cage fish farm, in Napoleon gulf, northern Lake Victoria. In-situ measurements of key environmental (temperature, dissolved oxygen, pH and conductivity) and biological (algae, zooplankton, macro-benthos) variables were made at three transects: Transect 1- the site with fish cages (WC); transect 2- upstream of the fish cages (USC-control) and Transect 3- downstream of the cages (DSC). Upstream and Downstream sites were located approximately 1.0 km from the fish cages. Environment parameters varied spatially and temporally but were generally within safe ranges for freshwater habitats. Higher concentrations of SRP (0.015-0.112 Mg/L) occurred at USC during February, September and at DSC in November; NO2-N (0.217- 0.042 mg/L) at USC and DSC in February and November; NH4-N (0.0054- 0.065 Mg/L) at WC and DSC in February, May and November. Algal bio-volumes were significantly higher at WC (F (2,780)=4.619; P=0.010). Zooplankton species numbers were consistently lower at WC with a significant difference compared to the control site (P=0.032). Macro-benthos abundance was consistently higher at the site with cages where mollusks and low-oxygen and pollution-tolerant chironomids were the dominant group. Higher algal biomass, concentration of low-oxygen/pollution-tolerant macro-benthos and depressed zooplankton diversity at WC suggested impacts from the fish cages on aquatic biota.

滇金丝猴栖息地植物多样性研究

采用路线调查与标准地调查相结合的方法,结合历史资料,对滇金丝猴栖息地的野生植物资源进行了实地野外调查研究,分析了植物多样性及其受威胁状况.结果表明:(1)栖息地具有丰富的植物物种多样性,有维管束植物217科789属3533种(含亚种、变种),其中,国家重点保护野生植物有117种;(2)该区植物区系成分具有复杂性、多样性,明显偏重于温带性质、且植物区系起源古老,有中国特有分布属90个,其中,古特有属59个;(3)该区具有丰富的植被类型,包括4个植被型组,10个植被型,47个群系,具有较高的保护和科研价值.同时针对栖息地植物多样性受威胁状况,提出了植被恢复、生态移民及社区共管是保护植物多样性的有效措施.

云南横断山区人口和农业统计量中的生态信息

云南横断山区以其生物多样性丰富著称，又是一个有国际兴趣的生态敏感区。然而，它也不乏生态忧患。乡村景观的实地考察说明：这些地区刀耕火种、轮歇耕作仍然盛行，不少居民已经面对着农牧业用地向林区过度扩张所致的水土流失、水源枯竭等严重环境问题。为了解问题之根源，我选择了该山区腹地的８个贫困县，１９９０年开展了人口和农业统计量的相关矩阵分析。结果表明：乡村人口与总人口，耕地面积与总人口、乡村人口，粮食产量和农业总产值呈显著正相关。但在实地考察中发现：人口的持续增量导致地面植被的覆盖率急速下降已成为一种生态警报。因此该山区的社会／经济发展和生物多样性保护都有赖于对生育控制的成功和耕作方式的改良

云南蜜蜂两新种(膜翅目: 蜜蜂总科)

三角胚彩带蜂Nomia (Lobonomia) trigonotarsis新种, 以中足负爪跗节椭 圆形, 后足胫节端部内侧具小的三角形片状突起, 生殖节的生殖刺突呈宽而扁平 片状, 7-8节 腹板形状不同而区别于近似种大叶彩带蜂(N. (L.)megalobata Wu) 。云南长足条蜂Elaphropoda yunnanensis新种, 以唇基强隆起, 中央不具脊; 后足基跗节外表面毛浅黄, 端部毛黑 褐色而区别于近似种黑跗长足条蜂(E. nigrotarsa Wu)。模式标本存第一作者单位, 部分副模存中国科学院动物研究所。图2参3(冯 维熊)

胰凝乳蛋白酶原激活过程的分子动力学研究

使用虚拟势法, 通过对不加虚拟势和加大小不等的虚拟势对胰凝蛋白酶原激活过程进行了模拟和比较, 对于激活过程可能具有的时间尺度以及过程中势垒的位置及性质都给出了一定的信息。图1表1参4