复合生物杀虫剂防治思茅松毛虫的初步研究

应用白僵菌、苏云金杆菌、马尾松毛虫质型多角体病毒 (DCPV)和 15 %保丰等 4种杀虫剂对 2～ 3龄思茅松毛虫幼虫进行了毒力测定。并通过林间正交试验设计筛选出了复合生物杀虫剂最佳组合A3 B1C3 D1,即白僵菌 1 4× 10 6孢子·ml-1+苏云金杆菌 1 6× 10 8孢子·ml-1+DCPV 5× 10 6PIB·ml-1+15 %保丰 4 0 0 0倍液。研究表明在复合杀虫剂中保丰、苏云金杆菌对防治效果有显著影响。林间大面积防治试验表明 ,复合杀虫剂的防治效果优于单一生物杀虫剂     

喜树幽斑螟防治技术研究

喜树幽斑螟是喜树的一种新害虫。该虫的综合防治应以生物防治为基础。试验表明,复合生物杀虫剂对幼虫有良好防治效果,低龄幼虫盛发期可喷洒Bt-8010　1-2×109孢子·ml-1+白僵菌1-2×108孢子·ml-1+80%DDVP1/20000;冬季树干涂白也有良好防治效果。     

绿僵菌产毒素能力及产毒素动态分析

以绿僵菌素A(DxtA)和绿僵菌素B(DxtB)的产量为指标,分析了僵菌属5个种15个菌株液体培养的产毒素能力差异,确定了高产毒素优良菌株,并拟合了高产毒菌株在摇瓶条件下的产毒素动态.结果表明,不同种绿僵菌间的产毒素能力差异极显著(P<0.01),黄绿绿僵菌(Metarhizium flavoviride)、戴氏绿僵菌(M. taii)和蚱蜢绿僵菌(M. acridum)均不产生毒素,鳞腮绿僵菌(M. lepidiotae)可产少量毒素,金龟子绿僵菌(M. anisopliae)产毒素能力最强,其中M19的DxtA产量最高(144.12 μg·mL-1), M25菌株的DxtB产量最高(65.31 μg·mL-1);M25菌株的综合表现最佳;M25菌株在液体摇瓶培养条件下DxtA产量经SPSS拟合,符合Logist模型:Y=84.99/(1+11.82×e-0.3X),即前4 d是营养生长,毒素分泌量较少,4 d后生物量维持平衡,第5天起毒素产量进入指数增长期,9 d后毒素产量进入平台期.     

从桔蚜上分离的一种致病镰刀菌

从福建省南平市桔蚜虫尸上分离的一株镰刀菌 ,病原鉴定为镰刀菌属 (FusariumLinkexFn)的砖红镰孢 (FusariumlateritiumNees .)。病原菌在PDA培养基上生长旺盛 ,10～ 3 5℃均可生长 ,生长适宜温度为 2 0～2 6℃ ,2 5℃下培养 3d后可产孢。分生孢子萌发最适宜温度为 2 0～ 2 5℃ ,最适宜的相对湿度为 96%～ 10 0 %。对桔蚜若虫的毒力测定表明 ,砖红镰孢对桔蚜具有较强的致病力 ,其LC50 为 2 71× 10 7个孢子·L- 1 ,LT50 为2 2 1～ 6 3 4d(在 1 0× 10 1 1 ～ 1 0× 10 7个孢子·L- 1 浓度下 )。用砖红镰孢菌液田间防治桔蚜 ,死亡率达91 80 %。     

不同来源绿僵菌对油桐鹰尺蠖幼虫的致病力比较

油桐鹰尺蠖Biston suppressaria (Guenée) 是一种杂食性食叶害虫,近年来在速生桉树林分中大 面积发生,造成较大的损失。文中研究了不同来源金龟子绿僵菌Metarhizium anisopliae 菌株生长与产孢 特性及对油桐鹰尺蠖幼虫的致病力,旨在筛选出高效防治该虫的生物资源。试验结果表明：不同来源的 绿僵菌菌株间菌落生长速度和产孢量差异显著,MaZPTR-01 菌株15 d 的菌落直径为6.5 cm,显著较其它 菌株大;MaFZ-13 和MaZPTR-01 菌株培养15 d 产孢量最高,分别为1.33×108 孢子· cm-2 和1.28×108 孢 子· cm-2。致病力测定结果表明：不同菌株对油桐鹰尺蠖幼虫的致病力存在显著差异,其中接种MaFZ-13 和MaZPTR-01 菌株的幼虫校正死亡率、僵虫率均较其它菌株高,接种后15 d 幼虫校正死亡率分别达到 94.5%、92.7%,僵虫率分别为75%、61.7%;这2 个菌株的致死中时（LT50）显著比其它菌株短,分别为 4.34 和4.52 d。绿僵菌MaFZ-13 和MaZPTR-01 菌株对油桐鹰尺蠖幼虫的致病力强,且具有良好的生产性 状,可作为该虫的生物防治资源进一步开发应用。     

长江中上游防护林体系工程林生物量及生产力计量评价

通过对长防林 (川江部分 )一期工程林所涉及的六个流域不同工程林类型的定位测定 ,结合林地生物量及生长监测资料 ,较为全面地对一期工程林生物量及生产力进行了计量评价研究。结果表明 :一期工程所造 2 4 4.6× 1 0 4hm2 森林 ,单位面积生物量为 1 7.38t/hm2～ 2 2 .91 t/hm2 ,平均值为 2 0 .4 3t/hm2 ,净生产力为 2 .0 5t/hm2· a～ 2 .34 t/hm2·a,平均值为 2 .2 2 t/hm2 · a。其中 ,针叶林、阔叶林、小灌木林、草地单位面积生物量分别为 2 2 .0 0 0 t/hm2、2 5.370 t/hm2、7.677t/hm2、9.1 30 t/hm2 ,平均净生产力分别为 2 .390 t/hm2· a、2 .756t/hm2 · a、1 .535t/hm2 · a、9.1 30 t/hm2 · a。一期工程林总生物量已达 4 1 1 9.9× 1 0 4t,其中长江上干流、沱江、涪江、嘉陵江、渠江、金沙江分别为 886.76× 1 0 4t、4 36.62× 1 0 4t、661 .70×1 0 4t、81 9.66× 1 0 4t、799.86× 1 0 4t、51 5.32× 1 0 4t     

溶剂置换材和气干材气体渗透性的比较研究

对杉木、马尾松各 5株生材进行了不同体积分数的酒精、丙酮和戊烷溶剂逐级过渡置换及气干 ,并通过水上升置换法对溶剂置换材和气干材的心材和边材流体渗透性进行了测定与分析。结果显示 :杉木和马尾松溶剂置换材的总体平均渗透性比气干材的渗透性高。杉木溶剂置换干燥生材心材为 2 1 6× 1 0 - 1 2m3·m- 1 ,气干材心材为 0 .1 1× 1 0 - 1 2 m3·m- 1 ,前者是后者的 1 9.7倍 ;杉木溶剂置换干燥生材边材为 4.72×1 0 - 1 2 m3·m- 1 ,气干材边材为 0 .99× 1 0 - 1 2 m3·m- 1 ,前者是后者的 4.7倍 ;马尾松溶剂置换干燥生材心材为 0 3 9× 1 0 - 1 2 m3·m- 1 ,气干材心材为 0 1 7× 1 0 - 1 2 m3·m- 1 ,前者是后者的 2 3倍 ;马尾松溶剂置换干燥生材边材为5 3 1× 1 0 - 1 2 m3·m- 1 ,气干材边材为 0 84× 1 0 - 1 2 m3·m- 1 ,前者是后者的 6 3倍。气干材和溶剂置换材的边材渗透性均大于对应的心材渗透性。溶剂置换对渗透性的影响 ,边材比心材明显。无论是杉木还是马尾松 ,较之于气干材 ,溶剂置换使得边材的渗透性均有较大程度的提高 ,而心材的渗透性 ,多数试材有一定程度的提高 ,少数则变化很小或有一定降低。     

苯乙烯、茴脑与肉桂醛的臭氧化反应竞争性研究

以苯乙烯为参照物 ,采用气相色谱跟踪肉桂醛与苯乙烯、茴脑与苯乙烯以及肉桂醛、苯乙烯和茴脑3种化合物的混合物的臭氧化竞争性反应 ,得出此 3种化合物的反应活性由大到小的顺序为茴脑、苯乙烯、肉桂醛 ;利用膜模型理论进一步求算出肉桂醛、茴脑与参照物苯乙烯的反应速率常数比为 0 .0 5 5和 2 5 .6 ,相应的反应速率常数分别为 72 0L·mol-1·s-1和 3.33× 10 5L·mol-1·s-1     

白僵菌生产工艺规范化技术的研究

通过对白僵菌不同工艺技术生产菌粉产孢量比较研究 ,筛选出工艺规范化生产各环节的最优组合技术参数 ,提出二级液体 (7%麦皮煮出液 )和三级固体培养基 (麦皮∶谷壳 =9∶1)及其液固接种量 (1∶1)最适配方 ,并确定前 3d三级固体开放培养发酵最适温度为 18～ 2 2℃、相对湿度为 95 %～ 10 0 % ,还总结出以二级液体振荡培养 6 0h接种 ,三级固体发酵培养 7～10d ,可获得最优质的菌粉 ,平均含孢量达 2 0 0× 10 8个·g-1以上 ,缩短生产周期 1/3 ,降低生产成本 ,增加菌厂经济收益 ,为菌厂大量生产提供参数依据。     

杨树纸浆林造林模式的研究

为优化杨树小径材纸浆林模式,采用多分子的正交试验方法,通过对试验数据的统计分析和比较,筛选出较理想的纸浆林模式为:①立地条件中上等:A2B1C2———美洲黑杨·1666株/hm2·1m×6m·集约经营·6年主伐;A3B1C2———欧美杨·1666株/hm2·1m×6m·集约经营·6年主伐。②立地条件稍差:A2B2C2———美洲黑杨·1111株/hm2·1.5m×6m·集约经营·7年主伐;A3B2C2———欧美杨·1111株/hm2·1.5m×6m·集约经营·7年主伐。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.