多效抗旱驱鼠剂室内驱避鸟兽试验研究

通过选食和迫食试验，多效抗旱驱鼠剂室内对大山雀、野灰鸽、小白鼠、小家鼠、鼠兔等有较强的驱避作用。选食试验，用RPA处理的种子保存率达78．3％－100％，迫食试验，达71．9％－89．6％，通过差异显著性检验，各处理间差异显著。     

多效复合剂在飞播造林中应用效果的研究

为加速半干旱地区荒山或偏远山区的绿化进程，解决飞播造林鸟鼠取食种子的难题，对研制的多效复合剂进行了应用效果的试验研究。试验结果表明，多效复合剂的３种主要成分其保水剂浓度小于５％，对油松种子发芽率没有影响；驱避剂以ＲＱ１．１％剂量效果最好，选食驱避率达９０％，迫食驱逐率可达７０％，减少种子损失率达３５％。苗木营养剂具有提高苗木生长量的作用，苗高和地径分别比对照提高１８．３％和４４．５％。     

两种细菌对鸟鼠驱避剂主要成份的拮抗作用

本试验采用平板测定法测定了两株菌株类产碱假单胞菌Ｐ７５１和蜡状芽胞杆菌ＢＣ７５２，对鸟鼠驱避剂主要成份福美双、涂料、石膏粉和氯偏的拮抗作用。经试验选育出抗福美双菌株９１０可与鸟鼠驱避剂复合包衣林木种子用于飞播造林，防病率达７１．３％，高生长量提高１７．６％。     

容器育苗药剂拌种试验效果调查

采用多效复合剂对容器育苗的种子进行了拌种处理，试验结果表明，处理的较对照对鸟鼠驱避率提高27．4个百分点，发病率降低12．37个百分点，起到了驱避鸟鼠和防止猝倒病发生的作用。     

多效复合剂在山杏直播造林中的应用

多次复合剂不但能驱避鸟鼠危害，提高出苗率，还能促进苗高、地径的生长。山杏采用多效复合剂处理后直播造林，每公顷减少鼠类危害126穴，出苗率平均提高9．6％；苗高、地径平均分别提高24％和38％。一次造林成功，达到规程标准。     

幼龄兰考泡桐胶合板材林营养补给效应的研究

连续４年对幼龄兰考泡桐胶合板材林进行营养补给效应研究的结果表明：造林后前二年营养补给对泡桐生长无明显促进效应，第三年采用Ｎ１００Ｐ２５Ａ３０进行营养补给，对泡桐胸径、胸高断面积和材积生长具有显著的促进效应，分别提高６．１０％，１２．７２％，１３．３４％，而对高生长无显著效应．其效应主因子为磷肥，次因子依次为氮磷交互、深度和氮肥，最佳营养补给组合为Ｎ１００Ｐ２５Ａ４０采用Ｎ１００Ｐ２５Ａ３０进行营养补给，具有显著的经济效益，其内部收益率可达１５．４６％．     

4种药剂防治桉树幼林白蚁试验

为防治土栖白蚁危害桉树幼林，选择4种药剂进行桉树容器苗浸根后上山造林试验和白蚁致死驱避试验。结果表明：容器苗经4种药剂浸根后造林，以绿僵菌复合剂的防治效果最好，幼林白蚁危害致死率仅3．4％；施用萘丸的防治效果最差，幼林白蚁危害致死率达20．5％，专项驱避试验对白蚁的驱避作用也不明显。文章还分析了几种灭除驱避白蚁药剂的成本和使用时应注意的问题。     

AciNPV复合杀虫剂的研制及应用的研究

本文重点对ＡｃｉＮＰＶ复合杀虫剂的研制进行了试验应用研究。通过对敌杀死、灭幼脲Ⅲ号、硼酸不同浓度防治试验，筛选出亚致死浓度：２．５％敌杀死为０．００５ｐｐｍ，２５％灭幼脲Ⅲ号为２５ｐｐｍ，硼酸为２００ｐｐｍ。与ＡｃｉＮＰＶ２．５×１０６ＰＩＢ／ｍｌ复合使用，３种化学制剂５种浓度都有增效作用，Ｌｔ５０较单用ＡｃｉＮＰＶ２．５×１０６ＰＩＢ／ｍｌ防治提前１．６７～３．９５天。防治效果：２．５％敌杀死＞２５％灭幼脲＞硼酸；复配药剂费用：硼酸＞２５％灭幼脲＞敌杀死。在研制ＡｃｉＮＰＶ复合杀虫剂或防治时，以２．５％敌杀死０．００５ｐｐｍ、２５％灭幼脲２５ｐｐｍ作为ＡｃｉＮＰＶ复合杀虫剂的复配药剂最佳浓度，成本低、增效作用明显     

动态信息

动态信息ＬＳＲＰ型、ＳＤＡ型系列宽带砂光机通过鉴定由青岛千川机械制造有限公司生产的ＳＲＰ型及ＳＤＡ型系列宽带砂光机，于ｌｏｐ年８月３０日通过了由青岛市委主持的产品鉴定会。该两系列产品是新型机电一体化产品，具有定厚砂光、精细砂光和定厚一精细砂三种工作方...     

多效抗旱驱鼠剂室内促长效果研究

室内用多效抗旱驱鼠剂对小麦、黄豆、油松、侧柏种子进行浸种、拌种处理。结果表明，300x的林用型和200x的农用型RPA对侧柏种子浸种效果最好，30x的林用型和80x的农用型RPA拌种效果最好，经检验分析，差异显著；500x的林用型和600x的农用型RPA对油松促长效更为明显，发芽率比对照提高25．2％－27．0％，平均高生长增加2．1－2．8cm，拌种型的两种药剂6个浓度对油松的发芽及生长影响比较明显，30x的林用型和40x的农用型可以使油松发芽率提高27．7％－29．8％，苗高增长0．6－1．3cm；对黄豆的发芽率提高12．0％－17．0％、13．8％－23．2％；侧根数量增加0．2－2．6、0．3－1．6条，平均苗高及生物量也有不同程度的提高；浸种型的RPA使小麦发芽率提高13．3％－23．3％，苗高增长5．1－7．5cm，根长增加0．6－1．8cm；拌种型RPA发芽率提高9．3％－22．6％，苗高增长4．7－6．6cm，根长增加0．4－1．6cm。     

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.     

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.     

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.     

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.     

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。