橄榄星室木虱化学防治试验

2002～2003年，采用90％万灵、21％毕达、25％阿克泰、50％库龙、2．5％功夫、20%艾美乐、40％速扑杀、10％蚜虱净、25％稻虱净等9种化学药剂，对橄榄星室木虱进行防治试验。根据防治效果、成本以及化学药剂的理化性质，筛选出万灵4000倍液、功夫2000倍液、蚜虱净1000倍液、毕达1000倍液等4种处理为最佳使用组合，防治效果分别为98．45％、97．85％、98．54％、92．35％，药剂成本2～3元／亩诙，可在生产上进行推广应用。     

三种杀虫剂对橄榄星室木虱的控制作用

应用生命表方法分析吡虫啉、木虱净、稻虱净3种化学农药对橄榄星室木虱的控制效果。结果表明：吡虫啉、木虱净、稻虱净和对照的种群趋势指数分别为0．4148，0．8328，4．9908，6．3925。说明吡虫啉和木虱净处理区的橄榄星室木虱种群数量呈下降趋势，稻虱净和对照区的橄榄星室木虱种群数量以4．9908和6．3925倍的速度增长；吡虫啉、木虱净和稻虱净的干扰作用控制指数分别为0．0649，0．1303和0．7807。表明吡虫啉和木虱净施用区种群数量相当于对照区的6．49％和13．03％，取得了很好的防治效果；稻虱净施用区种群数量是对照的78．07％，不是防治橄榄星室木虱的理想药剂。     

核桃桑白蚧药剂防治试验

利用40%速扑杀乳油、20%赛嗪杀扑磷乳油、5%高效氯氰菊酯白色乳剂、48%毒死蜱乳油和自制石硫合剂5种药剂在景东县文景镇者孟村核桃采穗园中进行核桃桑白蚧害虫药剂防治试验。结果表明,40%速扑杀乳油1 000倍液和20%赛嗪杀扑磷乳油1 000倍液的防治效果较为理想;5%高效氯氰菊酯白色乳剂2 000倍液和48%毒死蜱乳油2 000倍液的防治效果一般;自制石硫合剂防治效果较差。     

几种农药防治日本松干蚧试验

对吡虫啉(Imidacloprid)、阿维菌素(Abamectin)、速扑杀(Supracide)与氧化乐果(Omethoate)4种药剂配比度防治日本松干蚧的效果进行了试验分析，结果表明，药剂吡虫啉、阿维菌素与速扑杀均可取代40％氧化乐果，防效最佳配比度吡虫啉为5倍液，速扑杀与阿维菌素为3倍液。     

山地橄榄星室木虱防治初报

应用不同药剂、浓度对橄榄星室木虱(Pseudophacopteron canariumYang et Li)进行室内毒力测定和林间防治试验,结果表明:2.5%功夫菊酯乳油对橄榄星室木虱的毒力最高,其相对毒力是苦.烟乳油的1.7倍;复合药剂的防效明显高于单一药剂,最佳组合以功夫乳油5 500倍液+木虱净乳油6 000倍液+苦.烟乳油5 000倍液林间喷雾效果最佳,药后3 d、7 d、14 d、21 d的防效分别为73.63%、90.54%、93.51%、95.43%;连续施用复合药剂7 d的防效达100%,不仅防治效果好,而且持效长,可有效地控制星室木虱的危害。     

梨喀木虱与异喀木虱混合发生区防治药剂选择

用3类（生物剂、低毒、有机磷）8种药剂试验，结果表明：异喀木虱比梨喀木虱对药物的敏感性稍高，这也是田间异喀木虱种群小于梨喀木虱的一个原因。1.0%爱诺虫清3000倍液、20％梨虱霸乳油2000倍液、5％蚜虱净乳油1500倍液防治效果都在95％以上，1.0%爱诺虫清作为生物药剂，更适宜推广应用。     

板栗栗红蚧防治试验初报

选用 40 %速扑杀乳油、2 5 %敌杀死乳油、40 %氧化乐果乳油、5 0 %甲胺磷乳油、5 0 %敌敌畏乳油、2 0 %三唑磷乳油和 90 %晶体敌百虫等 7种农药对板栗栗红蚧若虫进行防治试验结果表明 ,杀虫效果以 40 %速扑杀 10 0 0倍液的防治效果最好 ,达 91%以上 ;用 2 5 %敌杀死 2 5 0 0倍液 ,40 %氧化乐果、5 0 %甲胺磷 10 0 0倍液 ,5 0 %敌敌畏 80 0倍液 ,效果次之 ,死亡率 70 %～ 84%;而用 2 0 %三唑磷乳油、90 %晶体敌百虫杀虫效果不佳 ,死亡率仅为 42 %。     

吡虫啉防治落叶松球蚜试验

作者对沙珠玉地区落叶松球蚜用 2 0 %、2 5 %吡虫啉、2 .5 %溴氰菊酯和 5 0 %氧化乐果进行了防治试验 ,结果表明 ,吡虫啉对落叶松球蚜具有优良的防治效果。 2 0 %和 2 5 %吡虫啉 1 2 5 0倍液防效率最佳 ,达 90 %以上。 2 .5 %溴氰菊酯和 5 0 %氧化乐果的防治效果不理想。     

8种药剂对紫薇梨象成虫的室内毒力测定及室外药效试验

选用8种药剂对紫薇梨象成虫进行室内毒力测定,筛选效果较好的药剂进行田间药效试验。结果显示,10%吡虫啉,20%氰戊菊酯和1%甲维盐的室内毒力效果较好,3种药剂的LC50在12 h分别为1.52,2.87,1.16 mg/L;在24 h分别为0.593,3.513,2.524 mg/L;在48 h分别为0.407,6.094,5.985 mg/L;在72 h分别为10.68,4.286,5.441 mg/L。3种药剂对紫薇梨象成虫的田间防治效果也较好,喷施10%吡虫啉3 000倍液、20%氰戊菊酯8 000倍液和1%甲维盐微乳油8 000倍液10 d后,田间校正死亡率均达到95%以上。     

几种药剂防治刺槐突瓣细蛾林间药效试验

刺槐突瓣细蛾Chrysaster ostensackenella (Fitch,1859)是我中心技术人员于2012年在开展林业有害生物野外调查工作时发现的一种重要外来入侵害虫。为筛选出有效的防治药剂,利用叶面喷雾、树干打孔注药的施药方式,对刺槐突瓣细蛾幼虫进行林间实验,喷雾后6 d,5%阿维菌素乳油防治效果为54.55%～81.48%, 25%吡虫啉可湿性粉剂防治效果为71.49%～81.54%,25%灭幼脲悬浮剂防治效果为36.37%～72.13%,25%甲维·灭幼脲悬浮剂防治效果为73.08%～82.26%,5.5%阿维·杀铃脲悬浮剂防治效果最好,达87.33%～97.55%;打孔注药后15 d,40%氧化乐果乳油原液或2倍液、25%吡虫啉可湿性粉剂5倍液防治效果均达90%以上。筛选出用5.5%阿维·杀铃脲悬浮剂2000倍+2000倍一加净渗透液喷雾,40%氧化乐果乳油2倍液和25%吡虫啉可湿性粉剂5倍液打孔注药对刺槐突瓣细蛾幼虫均有较好的防治效果。     

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.     

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.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

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.     

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.     

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。