Planting spacing affects canopy structure,biomass production and stem roundness in poplar plantations

To improve the productivity and wood quality of poplar plantations, effects of four planting spacing on canopy characteristics, biomass production and stem roundness in poplar plantations were evaluated over 8 years. Planting spacing influenced canopy characteristics of the plantations, and further affected the understory vegetation and plantation productivity. Understory vegetation biomass and Shannon-Wiener index were negatively correlated with leaf area index, but both diversity indexes and aboveground biomass of understory vegetation were higher in stands with a wider spacing. Tree diameter growth increased with increasing planting spacing, while the increment in plantations of square configurations (5?×?5 m and 6?×?6 m) was higher than those with rectangular configurations (3?×?8 m, 4.5?×?8 m). The highest poplar biomass production was achieved in the plantation with 5?×?5 m spacing at age 8. Moreover, poplar trees showed a tendency with better stem roundness in a square configuration. The results suggest that planting spacing not only affect canopy characteristics, understory vegetation and tree growth but also wood quality, and square configurations (5?×?5 m and 6?×?6 m) could be a better option for poplar plywood timber production at similar sites.     

赛里木湖新疆高原鳅种群结构研究

20 0 1年 6- 7月在新疆赛里木湖进行了新疆高原鳅种群结构的研究。共测量 32 2 4尾 ,1 7974g ,平均体重 5 6g ,体长波动在 2 1～ 1 6 1cm之间 ,平均体长 9 2cm ,雌雄比为1∶0 7,雌性群体体长、体重组成大于雄性。已经成为赛里木湖种群数量最多的鱼类     

Assessing the Illegal Bear Trade in Myanmar Through Conversations With Poachers: Topology,Perceptions, and Trade Links to China

Myanmar is home to Asiatic black bears and sun bears. We gained insight into illegal hunting and trade of these species in and out of Myanmar through conversations with 40 self-declared bear poachers. All respondents were males who typically killed or caught one to three bears a year, mostly by setting snares. There was a preference for Asiatic black bear. Perceptions were that bears were less abundant now than 5 years ago, but it was not more arduous to obtain one. Most poachers (75%) consumed less valuable parts and sold the remainder, whereas others trapped only to sell. Preferred tradable parts were gall bladder, meat, and paws. Chinese nationals or Burmese of Chinese descent were mentioned as playing key roles (ordering, buying, selling) in trade. Instead of focusing on poachers, we recommend that authorities focus on disrupting trade networks and markets. Cooperation with neighboring countries, especially China, is needed to stem the flow of bear parts.     

细粒棘球绦虫成虫表膜抗原特异性基因的筛选及克隆

为筛选细粒棘球绦虫(Echinococcus granulosus,Eg)表膜抗原基因或具有诊断性的特异性基因,提取Eg成虫表膜抗原,经ELISA、Western blot对该抗原的免疫学特性进行初步研究.以Eg成虫表膜抗原高免鼠血清为探针,筛选Eg成虫cDNA文库,将阳性噬菌斑的PCR产物和pGEM-T载体连接,转染到DH5α,对得到的重组子进行测序,并进行同源性分析.ELISA检测显示,表膜抗原免疫鼠诱导产生了特异性抗体,Westem blot鉴定该抗体能识别Eg成虫表膜抗原、原头蚴、Eg发育不成熟、Eg发育成熟抗原.筛选出6个阳性克隆,DNA片段大小在1～2kb之间.对阳性克隆进行同源性分析,结果与EgP-29mRNA同源性为99%,与Eg14-3-3蛋白mRNA同源性80%-99%.筛选Eg成虫cDNA文库所获得的基因,证明了Eg虫体表膜抗原的存在,有望成为犬细粒棘球绦虫的诊断抗原以及犬抗细粒棘球绦虫的候选基因.     

赛里木湖新疆高原鳅生物学研究

本文对赛里木湖新疆高原鳅的形态特性、生长、食性及繁殖习性等生物学进行了观察研究。经观测赛里木湖新疆高原鳅雌性体长7.8cm(6.0g)，雄性体长9.0cm(8.2g)达性成熟。繁殖时间5-7月，平均绝对怀卵量20096粒/尾。食性以钩虾为主，其次是摇蚊幼虫。本文还对新疆不同水域新疆高原鳅形态特征进行了比较，并就赛里木湖水域环境对新疆高原鳅的影响进行了探讨。     

新疆棉田化肥资源施用与产出效率特征

根据相关农业统计和农户调查资料,对新疆棉花生产中化肥施用与产出效率状况进行了分析.结果表明:近8 a来新疆棉田化肥投入量在400～450 kg/hm2之间徘徊.当前新疆棉田平均施用水平为429.1 kg/hm2,其中氮、磷、钾养分比例为1:0.63:0.027各地区棉田化肥分配很不平衡.棉田投入化肥的种类较单一,其中二铵为187.1 kg/hm2,占棉田化肥投入总量的44%,尿素为183 kg/hm2,占化肥总投入量的45%.新疆棉田化肥产出效率大都在2.9～3.7 kg/kg(棉花/化肥)之间,其中克孜勒苏柯尔克孜自治州、兵团略高,为4 kg/kg(棉花/化肥),巴音郭楞蒙古自治州、和田等地区较低,分别为2.8,2.5 kg/kg(棉花/化肥).最后对新疆棉田化肥投入应采取的宏观管理策略进行了讨论.     

Periodische und aperiodische Veränderungen in den Eigenschaften junger Marschböden im Deichvorland

Periodical and aperiodical changes of properties of young marshland soils seawards the dike The changes of properties of young marshland soils searwards the dike were investigated (1.) throughout the year, (2.) after storm tides, long drought periods and intensive rainfalls, and (3.) in the course of the low-high tide cycle. - In each case the relative cation distribution of the saturation extract remained constant. The relative distribution of the mobile cations remained also constant within the low-high tide cycle, white it shows fluctuations with a deviation of up to 16 % from the mean Na-content within the oneyear investigation and up to 28 % after extreme climatic or storm tide conditions. The annual salt fluctuations were determined to be at least 60–80 %. The deviations from the mean salt content were at least 100 % after storm tides and long drought periods (extreme deviation of 370 % within the first 1–3 cm soil) and partly also after heavy rain. The redox conditions remained constant within the low-high tide cycle, whereas they differed to a small extent following extreme climatic or storm tide conditions. With values of 0.4–0.9 the soils showed a small spectrum of different Ca/Mg ratios. Moreover, the determined annual fluctuation of the Ca/Mg ratios showed that the Ca/Mg ratio is not a suitable classification criterion.     

阿克苏河叶尔羌高原鳅Triplophysa(Hedinichthgs)yarkandensis(Day)生物学研究

本对阿克苏河叶尔羌高原鳅的形态特征、群体结构、繁殖、食性等生物学进行了研究。叶尔羌高原鳅体长分布在3．0～15．0cm之间，体重分布在1～33g之间。W=0．039748L^263049.Fulton肥满度雌体平均为1．54，雄体平均为1．46；Clark肥满度雌体平均为1．25，雄体平均1．16。雌体成熟个体最小体长为6．6cm，体重为5．5g，平均绝对怀卵量11543粒／尾。食性以底栖动物、水生昆虫以及鱼类幼体为主。     

EgM9免疫犬引起细胞因子表达的变化规律研究

用重组表达蛋白EgM9免疫犬,通过实时定量PCR方法检测IFN-γ和IL-4表达的变化规律.用Trizol试剂提取新鲜全血的总RNA,取0.5μg总RNA,采用实时定量PCR法逆转录扩增IFN-γ、IL-4和内参基因G3PDH,扩增产物经电泳分离后,用凝胶图像分析仪照相和扫描分析,检测其相对表达量.IFN-γ、IL-4...