落叶松人工林采集作业模式的优选

以黑龙江省带岭林业局落叶松人工林为试验点,采用4种不同的采集作业模式,应用层次分析法,综合考虑作业成本、作业效率、保留木损伤、土壤干扰以及木材损耗5个指标,定量计算平缓坡和陡坡条件下不同采集作业模式的综合效益.结果表明:择伐-畜力集材作业模式是该类型伐区最适宜的作业模式.     

修剪和生长调节剂对青海云杉苗芽生长发育的影响

对5年生和7年生青海云杉苗进行了不同方式的修剪,同时用不同的生长调节剂对其主干和侧枝上的芽进行了处理,发现除去青海云杉顶芽,能够促进苗木侧芽和隐芽的生长发育,提高侧芽的抽枝率,增加新枝的生长量.不同种类的生长调节剂和修剪方式对青海云杉芽的生长发育影响效果显著不同,去顶芽修剪的效果优于纺锤形修剪和篱式修剪,对于7年生苗,主干上仅留3个饱满芽的强度修剪能明显地减少主干上的芽数,使抽枝数也随之减少,处理效果最差.去顶芽能够明显的增加当年新梢数量和长于6 cm的新梢总长度,同时还能增加当年新梢上冬芽数.6BA对青海云杉芽和枝条的生长发育有较好的促进作用,抽枝宝在各个修剪处理中表现均最差,甚至在一定程度上抑制了青海云杉芽的萌发和延长生长.修剪和生长调节剂处理对5年生苗侧枝芽抽枝数影响均极显著,而对7年生苗的影响却不显著;修剪和生长调节剂的交互作用明显地影响了对7年生苗的处理效果,而对5年生苗的影响不显著.去顶芽后再用6BA涂抹青海云杉苗上的保留芽,能有效地促进青海云杉保留芽的生长发育,有利于形成更多枝条,对青海云杉采穗圃苗的处理效果最佳,强度修剪和用抽枝宝抹芽不适于青海云杉采穗圃苗的培育.     

宁波东钱湖山体生态林优化的群落学解析

以东钱湖生态林优化模式为例，提出地带性植被类型是从大尺度上确定生态林优化目标的依据，而具体地点生态林优化模式确定的依据是该地点的潜在植被类型；生态林优化模式的群落结构(主要包括种类组成和配比)的确定主要是借助群落学手段参考天然森林群落的特征而制定：最后就群落学手段选择植被优化模式的特点作初步探讨。     

Combined effect of wood moisture content,drill bit rotational speed and feed rate on drilling resistance measurements in Norway spruce (Picea abies (L.) Karst.)

ABSTRACT

An IML-RESI PD 400 drilling tool and a standard spade drill bit (IML System GmbH, Wiesloch, Germany) were used to study the combined effect of wood moisture content (MC), drill bit rotational speed and feed rate on drilling resistance (DR) and feeding force (FF). Tests were made with Norway spruce (Picea abies (L.) Karst.) conditioned in a normal climate (20°C/65% RH), at 20°C/95% RH, vacuum-pressure impregnated in water, and oven-dried. Rotational speeds and feed rates had an impact on feed rate per cutting edge for the major cutting edge of the drill bit which was used for correlation with DR and FF for various MC. Impact of MC on DR and FF depended on rotational speeds and feed rates of the drill bit. For feed rates per cutting edge less than 0.09?mm, DR was higher for water saturated (WS) specimens. Negligible differences between DR for various MC were found for feed rates per cutting edge between 0.09 and 0.15?mm. DR was higher at low MC for feed rates per cutting edge which were higher than 0.15?mm. FF extremely increased in conditioned (20°C/95% RH) and WS specimens at feed rates per cutting edge less than 0.1?mm.     

Changes of decay and termite durabilities of Japanese larch (Larix leptolepis) wood due to high-temperature kiln drying processes

We investigated the effects of high-temperature drying schedules (120°–130°C) on decay and termite feeding of Japanese larch timbers. Thermogravimetric analysis was conducted to investigate changes of the wood components. Decay and termite feeding tests showed that specimens dried under high-temperature schedules were susceptible against a decaying fungus Fomitopsis palustris and attacks from termites Coptotermes formosanus and Reticulitermes speratus. These drying schedules changed chemical components, which were suggested by the thermal analytical result compared to the control sample. The results of this study indicated that the acceleration of termite feeding takes place even under temperatures that are comparatively lower than that used in our previous research in which 170°C steaming treatment was applied to Japanese larch wood. Decay durability against a brown rot fungus also decreased, possibly from production of low molecular weight fragments when hemicellulose decreased during the high-temperature drying processes.     

Interaction effect of whole wheat feeding and mannanoligosaccharides supplementation on growth performance,haematological indices and caecal microbiota of cockerel chicks

The interaction effect of whole wheat feeding and mannanoligosaccharides supplementation on growth performance, haematological indices and caecal microbiota of cockerel chicks were investigated using 250‐day‐old cockerel chicks previously reared for 7 days pre‐experimental period. Birds were fed with commercial chick mash during the pre‐experimental period. At the expiration of this period, 192 chicks were selected on weight equalization basis and assigned into 24 pens. Each treatment consisted of six pens, while each pen housed eight birds. Four wheat–soya bean‐based experimental diets were formulated in a 2 × 2 factorial arrangement of diets having two wheat forms (ground and whole wheat grain) each supplemented or not with 1 g/kg MOS/kg feed. Whole wheat feeding (irrespective of MOS supplementation) showed reduced (p < 0.05) feed intake. Birds fed whole wheat diet supplemented with MOS recorded the highest (p < 0.01) final live weight, weight gain and the best (p < 0.05) feed conversion ratio. Haemoglobin concentration, packed cell volume and red blood cell count of the chicks were not affected (p > 0.05) by dietary treatment. However, dietary supplementation with MOS resulted in increased (p < 0.05) WBC counts. The caecum content of chicks fed with MOS‐supplemented whole wheat diets recorded the least (p < 0.01) salmonella counts. In conclusion, combination of whole wheat feeding and MOS supplementation showed improved growth performance, gut microbiota and indications of improved health status of cockerel chicks.     

Beef quality traits of heifer in comparison with steer,bull and cow at various feeding environments

The present review has been focused largely on the sex type differences in beef quality among heifers, cows, steers and bulls in various feeding environments. Genetic groups, feeding systems and gender are the major factors that change carcass characteristics and fatty acid profiles of cattle. Studies identified that heifer beef has super characteristics in eating quality and a better healthy composition in fatty acids than steer, cow and bull. Diet influences the variation of fatty acid profile; particularly the level of polyunsaturated fatty acids (PUFA) interacts with breed and sex. Animals finished in pasture systems were reported to show better ratios of PUFA/ saturated fatty acids and n‐6/n‐3. Carcasses of roughage‐fed beef are lighter and have less marbling and lower quality grades but have higher cutability than carcasses of grain‐fed bulls. Heifers and cows are reported to deposit more fat than steers and bulls. Among males, lower production of testosterone by steers favors more fat thickness compared with bulls. Marbling greatly varies among cattle belonging to different sexes, and particularly, females have genetic makeup that efficiently controls deposition. The current review identified that heifers can be a premium beef brand, while steer beef currently take a large part of market share across the world.     

养殖模式对冬季商品肉鸭舍温湿指数的影响

选择1日龄健康樱桃谷SM3系商品代肉鸭18 490羽,随机分为网上(N组)和发酵床上(B组)2组进行饲养,监测冬季一个完全生长周期内(42d)鸭舍温度(T)、相对湿度(RH)及温湿指数(THI)变化,探讨不同养殖模式对商品肉鸭舍温湿指数的影响。结果表明:N组和B组舍内平均温度均明显高于平均气温;N组舍内温度全部高于B组,N组平均温度比B组高8.32℃,差异显著(P0.05)。N组和B组舍内相对湿度均明显高于室外;N组舍内平均相对湿度比B组高2.47%,无显著性差异(P0.05)。试验期N组有16d处于热应激状态,B组有6d处于冷应激状态。结果提示,在北方寒冷气候下网上供暖养殖模式能为商品肉鸭提供更舒适的温湿度条件。     

四种杀虫剂LC25对Q型烟粉虱成虫取食行为的影响

【目的】利用刺吸电位技术（electronic penetration graph,EPG）研究Q型烟粉虱（Bemisia tabaci）成虫对吡虫啉、吡蚜酮、螺虫乙酯和溴氰虫酰胺4种杀虫剂LC₂₅处理24 h番茄苗的取食行为,探明内吸性杀虫剂亚致死剂量对烟粉虱成虫取食行为的影响。【方法】以无农药暴露史的Q型烟粉虱成虫为供试昆虫,番茄品种‘粉印三号’为供试植株。通过水培生测法确定4种内吸性杀虫剂的亚致死浓度LC₂₅。在此基础上利用EPG监测Q型烟粉虱成虫取食寄主的13个非韧皮部指标和8个韧皮部指标,并对叶片刺吸孔进行显微观察。以无农药处理为对照（CK）。【结果】4种杀虫剂对Q型烟粉虱成虫的LC₂₅值为溴氰虫酰胺>吡蚜酮>吡虫啉>螺虫乙酯。在总记录时间8 h内,Q型烟粉虱成虫的取食在各处理中均产生非刺探波（np）、路径波（C）、电位下降波（pd）、韧皮部分泌唾液波（El）、韧皮部被动吸食波（E2）以及木质部主动吸食波（G）6种波形。在非韧皮部的np波次数上,溴氰虫酰胺处理的次数最多,其次是螺虫乙酯处理,两者间差异不显著（P>0.05）,但均显著高于CK和吡虫啉处理（P<0.05）。C波和G波总持续时间均为CK处理最长,溴氰虫酰胺处理最短,两处理间差异显著（P<0.05）。CK处理的pd波总持续时间显著长于4种杀虫剂处理（P<0.05）,其中螺虫乙酯处理最短,但4种杀虫剂处理间差异不显著（P>0.05）。螺虫乙酯处理的F波总持续时间最长,吡虫啉处理最短,两者间差异显著（P<0.05）。CK处理韧皮部的E1波和E2波总持续时间分别为20.52和50.60 min,显著长于吡虫啉处理和溴氰虫酰胺处理对应波的总持续时间（P<0.05）,但E1波总持续时间与吡蚜酮和螺虫乙酯处理均差异不显著（P>0.05）。【结论】4种杀虫剂LC₂₅均引起Q型烟粉虱成虫的拒食行为,为研究烟粉虱或具刺吸式口器农业害虫对4类杀虫剂亚致死效应的拒食作用机理及防治提供了理论依据。     

尼勒克县荒漠草地植物种类调查及分析

为了更好的保护尼勒克县荒漠草地植物资源,采用样方和植物踏查法对尼勒克县荒漠草地的植物种类进行调查研究。结果表明：尼勒克县荒漠草地有23科68属98种（亚种）植物,植物种类组成较丰富,有害植物少。藜科、菊科和禾本科为优势科,含有54种（亚种）植物;小型科和单科种类众多,单科植物有12种。按照经济类群划分,豆科植物占8.16%,禾本科植物占13.27%,藜科植物占27.55%,菊科植物占14.29%,莎草科植物占3.06%,杂类草占33.67%。按照饲用价值划分,优良占14.29%、良好占27.55%、一般占36.73%、差占16.33%、有毒占5.10%。