浙江上虞杨树病虫害种类调查

采用普查和重点调查相结合的方法,对浙江省上虞市海涂杨树防护林病虫害种类和为害程度进行了较为系统的调查,收录杨树虫害41种,分别隶属4目21科,病害8种。收集浸渍幼虫标本30余件,针插标本近300件,其中包括了杨树的主要害虫。并且对绝大部分标本在收集的第一现场进行了摄影记录。     

Detection of protection benefits for predatory fishes depends on census methodology

1. Marine protected areas (MPAs) are used as fisheries management and conservation tools. Well-enforced no-take zones allow the rebuilding of natural populations of exploited species; however, there is still controversy on the role of buffer zones.
2. The effectiveness of MPAs could be underestimated, as fish population assessments depend largely on traditional methodologies that have difficulties in detecting predatory fish because of their low abundances, their patchy distribution, and their reaction to the presence of divers.
3. The performance of different census methods was compared in assessing the protection benefits for large predatory fishes under different protection levels (i.e. no-take and buffer zones) in five Mediterranean MPAs. Specifically, conventional strip transects (CSTs, 50 × 5 m²) and tracked roaming transects combined with distance sampling (TRT + DS, variable lengths) were compared, including a series of TRT-derived estimators with variable transect lengths and fixed widths of 20, 10, and 6 m (TRT20, TRT10, and TRT6, respectively). Additionally, the effectiveness of the MPAs studied and protection levels for conserving large predatory species was evaluated.
4. Transects covering larger areas (i.e. TRT + DS and TRT20) allowed the detection of a greater number of species and yielded more accurate estimates of density and biomass than transects of narrower fixed widths, particularly the CSTs, which were associated with the lowest richness detection capability, accuracy, and precision. On average, both no-take zones and buffer zones appeared effective for the conservation of predatory fishes, indicating that multiple protection areas were ecologically effective. Differences between MPAs were also observed, however, probably arising from both local environmental and management factors.
5. We suggest the implementation of methodologies with larger transects for the study of large predatory fish, combined with CSTs for the rest of the fish community, in order to avoid biases in predatory population assessments, which are key indicators of MPA effectiveness.

     

高山峡谷地区土地资源卫星遥感技术研究

采用卫星磁带计算机处理,航、卫片结合调查,不同比例尺嵌合成图和简化的净耕地系数综合区划取样法,线状地物调左的镜测及数学模型修正,农村居民点分区多点抽样测量等新技术和新方法可解决高山峡谷地区土地资源调查中的技术难题.     

一个种猪场猪伪狂犬病疫情四年追踪调查报告

对某中型集约化种猪场４年继发猪伪狂犬病疫情进行了追踪调查。疫病流行于带仔母猪舍，主要是７￣１２日龄仔猪发病，１９９４年暴发流行时，窝发病率为４３．７％，发病窝仔猪发病率为８６．７％，病死率为９３％。疫情平息后，对全场经产母猪接种过伪狂犬病疫苗。１９９５￣１９９７年在带仔母猪舍又继发流行，窝发病率分别为３２％，３４％和２９％，其发病窝仔猪发病率和病死率较首发时低。