黄土丘陵沟壑区不同植被恢复类型昆虫群落结构及多样性的研究

为探讨黄土高原植被恢复过程中植物与昆虫群落的关系,评价人工植被和自然恢复植被种类搭配的合理性,为退化生态系统的植被恢复提供依据。采用样地调查法,在黄土丘陵沟壑区纸坊沟流域研究比较了不同植被恢复类型昆虫群落组成、结构及多样性的变化。结果表明,2种不同植被恢复类型区昆虫有189种(含蜱螨目),分别隶属13目84科。而不同植被恢复类型昆虫群落的物种数、丰富度、多样性、均匀度及优势度指数值均有明显差异。以20a自然封育植被恢复区昆虫群落的物种数、丰富度、多样性、均匀度指数值均较高,其值分别为160、21.17、1.4914和0.6918。优势度则以人工治理区(0.7251)>自然封育区(0.5845)。说明从人工治理区到自然封育区,随着植被种类增加,昆虫种类相应增加,优势种由突出降至不明显,昆虫群落稳定性提高。     

中国西藏大叶蝉亚科二新种(半翅目:叶蝉科)

记述采自中国西藏的叶蝉科大叶蝉亚科窗翅叶蝉属Mileewa Distant 1新种——易贡窗翅叶蝉Mileewa yigongana Yang,sp．nov．和斑大叶蝉属Anatkina Young 1新种——多色斑大叶蝉Anatkina polycolora Yang,sp．nov．。模式标本保存在中国农业大学昆虫学系。     

河南兜姬蜂属一新种(膜翅目:姬蜂科)

报道采自河南的兜姬蜂属Dolichomitus Smith 1新种：济源兜姬蜂Dolichomitus jiyuanensis Lin,sp．nov．。模式标本保存在国家林业局森林病虫害防治总站。     

佛司可林类成分的光谱特征（二）

活性二萜佛司可林A、B、C、D,已从毛喉鞘蕊花分离得到。本文根据一维和二维的核磁共振谱详细描述了它们的光谱特征,改正了原先错误的指定。     

草原蝗灾的"元凶"

其实每次草原蝗灾暴发,造成严重危害,都不是一种蝗虫引起的,而是几种模样迥异,习性不同的蝗虫共同泛滥为害的结果。在内蒙古草原可引起蝗灾的蝗虫包括有毛足棒角蝗、褐色雏蝗、宽须蚁蝗、皱膝蝗、白边痂蝗、小翅雏蝗、宽翅曲背蝗、红腹牧草蝗、条纹鸣蝗、异爪蝗、狭翅雏蝗等等。本文中的所有图片都是中国科学院康乐研究员所拍摄,这是他在草原上十多年研究期间积累下来的,是研究草原蝗虫珍贵的第一手资料,本刊为首发。     

互联网时代的医院危机公关管理

在市场经济条件下,市场环境、顾客需求、技术创新不断变化,都会给医院发展带来风险,如果医院不能及时防范就会形成医院公关危机,给医院造成重大损失。以网络、信息特征为特点的互联网时代的到来,更是给医院公关危机管理带来了新的挑战。强调潜在风险防范,防止多米诺骨牌效应,对于提升医院竞争力,保持医院良性运转具有极其重要的意义。     

人工合成甘蓝型油菜特长角变异系的选育

用中国西藏东部采集的1个白菜型油菜地方品种与云南甘蓝类蔬菜白花芥蓝远缘杂交,人工合成了甘蓝型油菜新材料,从杂种后代中通过系统选育,获得了1个特长角变异系,其主花序中部角果平均长度20cm左右,果身长16～18cm,果喙长3cm左右.从中获得的极端最长角果达31.5cm,果身长26.1cm,果喙长5.4cm.这是迄今芸苔属植物中很少见到的长角果油菜材料.该材料的平均角果长度大约为普通甘蓝型油菜的3倍左右,遗传已基本稳定,定名为川农特长角.本文报导其选育经过和主要特征特性,并对其育种和研究利用价值作了简要分析.     

人工栽培铁皮石斛菌根的细胞学研究

从细胞学水平上研究了人工栽培铁皮石斛的菌根特征。结果表明:真菌与铁皮石斛根成功地形成了菌根,真菌菌丝穿透根被细胞,并在根被的某个细胞中定殖,然后经由外皮层的通道细胞进入皮层薄壁细胞;皮层薄壁细胞层正是真菌与植物体相互作用的活跃部位;真菌侵染大多数的皮层薄壁细胞,并不能侵染内皮层及中柱细胞,从而使根仍然保持生活力。     

Comparison of adult mosquito community structure on various habitats

The community structure of adult mosquitoes was compared from New Jersey light trap collections in six different types of habitats in Citrus County, Florida, USA. From October 1998 to December 2000, mosquitoes were collected three times a week from the following habitats (swamps, swamps and freshwater marshes, pine fiat-woods, pine fiat-woods and scrub, salt marshes, and salt marshes and mangroves). Mosquito density was highest in the swamps and freshwater marshes habitat, with an average of 95.65 specimens per trap.Density was lowest in the flatwoods and scrub habitat, with an average of 14.38 specimens per trap. Species dominance differed among habitats. Salt marshes produced the greatest aggregation index, while pine flatwoods produced the lowest. Conversely, diversity analysis showed that pine flatwoods had the greatest diversity, while salt marshes the lowest diversity. Similarity indices indicated that the adult mosquito communities from pine flatwoods and pine flatwoods and scrub were very similar (0.8583). The adult mosquito community of salt marshes was different from that of swamps and freshwater marshes (the similar index was 0.0217).     

Spatial heterogeneity and population risk analysis of cotton bollworm, Helicoverpa armigera, in China

In this study, semivariance was used to quantitatively measure the spatial heterogeneity for the egg population of cotton bollworm during a growing season. The typical characteristic parameters of theoretical semivariance models against lag distances were applied to measure components of spatial heterogeneity： trend, range, spatial dependence, and the strength of spatial dependence. Then, kriging interpolation was used to evaluate the population risk of cotton bollworm exceeding economic thresholds. From early June through early September, the population densities were sampled 10 times in the study field. Results showed that the spatial patterns were related to population density. For its low-density population, the spatially heterogeneous trends were usually of spherical shapes; but for highdensity ones, the trends shifted to Gaussian shapes. The spatial dependence appeared at varied distances ranging from 52 meters to 936 meters, and the spatial dependence was in the range of 0.39-288.60, which changed with population densities. While having high heterogeneity, the strength of spatial dependence became much stronger. Results of population risk analysis showed that there was a high risk during its early stages, especially in mid-June. In August, population risk was so low that it did not need to be controlled.