鱼笼诱捕鱼类的渔具结构与渔法特点

1996—1997年,我们设计了几种不同形状、不同尺寸的鱼笼,在东山、漳浦两地进行鱼笼诱捕鱼类的一系列海上生产试验。本文主要介绍这几种鱼笼的结构及该种作业在生产上的渔法特点。     

线截抽样中两个样本被同时抽中的概率及其协方差的研究

通过对线截抽样中样本间两两同时出现的概率进行研究，解决树木间的协方差问题，以便通过一条样线对总体作出估计     

星源通掌上森林调查仪面积测量精度研究

Xingyuangtong handhold forest inventory instrument is a microcomputer-based Hi-tech product integrating remote sensing, mobile GIS and GPS, which is developed by 3S research center of Shenzhen Polytechnic. It can be used in forest resource inventory, area calculation on map, area survey on the spot, compartment and sub-compartment mapping and editing based on remote sensing images or scanned relief maps, interactive query and amendment between graphics and its attributes,etc. On the basis of theory analysis of area survey principle, the practical area survey precision of nine different-sized plots in different period of time and under different interfered conditions is analyzed in order to study the possible precision of area survey on the spot by using this product. It is demonstrated that Xinyuantong handhold forest resource inventory instrument can meet the precision needs of returning the grain plots to forestry, acceptance check of forestation land, area survey of compartment and subcompartment, etc. This product can be widely used in forest resource inventory.     

Frequency and distribution of herbicide resistance in Raphanus raphanistrum populations randomly collected across the Western Australian wheatbelt

In 2003, a random survey was conducted across the Western Australian wheatbelt to establish the extent and frequency of herbicide resistance in Raphanus raphanistrum populations infesting crop fields. Five hundred cropping fields were visited, with 90 R. raphanistrum populations collected, representative of populations present in crop fields throughout the Western Australian wheatbelt. Collected populations were screened with four herbicides of various modes of action that are commonly used for the control of this weed. The majority of Western Australian R. raphanistrum populations were found to contain plants resistant to the acetolactate synthase (ALS)‐inhibiting herbicide chlorsulfuron (54%) and auxin analogue herbicide, 2,4‐D amine (60%). This survey also determined that over half (58%) of these populations were multiple resistant across at least two of the four herbicide modes of action used in the screening. Only 17% of R. raphanistrum populations have retained their initial status of susceptibility to all four herbicides. The distribution patterns of the herbicide‐resistant populations identified that there were higher frequencies of resistant and developing resistance populations occurring in the intensively cropped northern regions of the wheatbelt. These results clearly indicate that the reliance on herbicidal weed control in cropping systems based on reduced tillage and stubble retention will lead to higher frequencies of herbicide‐resistant weed populations. Therefore, within intensive crop production systems, there is a need to diversify weed management strategies and not rely entirely on too few herbicide control options.     

使用BASIC语言计算大界闭合差

本文介绍了笔者编制的一套用于求算闭合差的程序,该程序功能强大,计算速度快,用学习机即可使用。适合森林调查的外业使用。     

Concurrent assessment of fish and habitat in warmwater streams in Wyoming

Abstract  Fisheries research and management in North America have focused largely on sport fishes, but native non-game fishes have attracted increased attention due to their declines. The Warmwater Stream Assessment (WSA) was developed to evaluate simultaneously both fish and habitat in Wyoming streams by a process that includes three major components: (1) stream-reach selection and accumulation of existing information, (2) fish and habitat sampling and (3) summarisation and evaluation of fish and habitat information. Fish are sampled by electric fishing or seining and habitat is measured at reach and channel-unit (i.e. pool, run, riffle, side channel, or backwater) scales. Fish and habitat data are subsequently summarised using a data-matrix approach. Hierarchical decision trees are used to assess critical habitat requirements for each fish species expected or found in the reach. Combined measurements of available habitat and the ecology of individual species contribute to the evaluation of the observed fish assemblage. The WSA incorporates knowledge of the fish assemblage and habitat features to enable inferences of factors likely influencing both the fish assemblage and their habitat. The WSA was developed for warmwater streams in Wyoming, but its philosophy, process and conceptual basis may be applied to environmental assessments in other geographical areas.     

萤光拖网推广试验的研究报告

本文报道了1996—1997年萤光拖网推广试验的结果,比较和分析了不同光周期下,萤光网的作业效率变化及其对不同渔获类型的捕获效应关系。试验表明,太阳光、月光和天气变化都对萤光网的作用效率产生影响,这种影响因渔获类型的不同表现各个相同,并伴随昼夜交替而发生变化。萤光网对各类型渔获的最有利捕捞时间,大多在黄昏至夜间的低照度下;萤光网对不同捕捞对象有不同的效应,具有种间差异大,并与其生态类群存在密切联系的特点。本试验研究结果,符合于海洋动物视觉功能的特征,也符合于海洋动物生态类群的一般规律。     

Inter-calibration of three electric fishing techniques to estimate 0+ juvenile fish densities on sandy river beaches

Abstract  The efficiencies of three different techniques for 0+ fish point abundance sampling by electric fishing were tested on a sandy beach of the Morava River, Czech Republic. During direct electric fishing (DE), the operator immerses an anode fastened on an extension pole. During thrown anode electric fishing (TE), the anode is thrown at a distance from the bank. During remote electric fishing (RE), a pre-positioned anode is activated after allowing sufficient time for fish to recolonise the area. The DE technique was found to disturb fish and that fish tend to escape, thereby reducing its efficiency (30% of efficiency of RE). There was no significant difference in relative abundance estimates or size structure of assemblages between DE and RE, but TE seemed to be a species selective technique on sandy river beaches, significantly overestimating relative abundance of bleak. Of the three techniques tested, RE was the most efficient and if time required for deployment could be reduced, it would be also the most suitable for monitoring 0+ fish assemblages on sandy river beaches.     

海南岛空心莲子草天敌昆虫种类调查

对海南岛空心莲子草的天敌昆虫种类进行调查。结果表明，海南岛空心莲子草的天敌昆虫有：稻棘緣椿象、中华稻蝗、短额负蝗、白条细蝗、条纹褐蝗、短角外斑腿蝗、褐背細斯、莲草直胸跳甲、虾钳菜披龟甲、甜菜螟、豆卷叶螟、斜纹夜蛾、豆蚜13种，隶属于半翅目、直翅目、鞘翅目、鳞翅目、同翅目5个目中的缘蝽科、蝗科、螽斯科、叶甲科、铁甲科、螟蛾科、夜蛾科、蚜科8个科。其中莲草直胸跳甲、虾钳菜披龟甲、甜菜螟有很好的利用价值或利用的潜力。     

不同源传染性法氏囊病病毒的分离及其生物学特性分析

用传染性法氏囊病病毒 ( IBDV)单克隆抗体夹心抑制 EL ISA对麻雀、鸭、鹅进行了血清学调查 ,阳性率分别为 7.4% ( 4/ 54 )、95.5%( 3 6 3 / 3 80 )、9.4% ( 1 1 / 1 1 7)。从 IBD阳性麻雀、IBD病鸡以及同群饲养的鸭、鹅体内分离到了 4株不同源病毒 ,IBDV单克隆抗体夹心 EL ISA、Dig-标记 IBDV c DNA探针斑点杂交和交叉中和试验证明该病毒均为 IBDV血清 型。病毒可适应并致死鸡胚 ,适应于鸡胚成纤维细胞并产生细胞病变效应 ( CPE)。病毒代谢抑制试验证明其基因组为 RNA,病毒对乙醚不敏感 ,p H2 .0不能灭活病毒 ,p H 1 2可使病毒失去感染性 ,56℃作用 3 h病毒仍有活性 ,70℃ 1 h可灭活病毒。以上结果表明 ,从鸡、麻雀、鸭、鹅体内分离到的 IBDV生物学性质比较稳定且非常相似。本研究结果提示 IBDV已在我国广泛流行 ,麻雀、鸭、鹅可成为 IBDV携带者或传染源 ,在 IB-DV传播和生态变异中起重要作用