云斑天牛对核桃树的危害与防治——以雷波县为例

核桃是四川省雷波县的支柱产业,在发展之初,由于对云斑天牛危害估计不足,在最近两年造成大面的核桃树受害.关于如何防治云斑天牛,列举了5种方法.随着当地政府重视,云斑天牛病得到控制,核桃产业在雷波县得到更大发展.     

云斑天牛对核桃树的危害与防治——以雷波县为例

核桃是四川省雷波县的支柱产业，在发展之初，由于对云斑天牛危害估计不足，在最近两年造成大面的核桃树受害。关于如何防治云斑天牛，列举了5种方法。随着当地政府重视，云斑天牛病得到控制，核桃产业在雷波县得到更大发展。     

常州市垂柳三种天牛的无公害防治技术试验

常州市垂柳Salix babylonica上,星天牛Anoplophora chinensis,云斑天牛Batocera horsfieldi和桑天牛Apriona germari混合发生。为降低危害整株柳树的天牛虫口率,根据常州当地的自然气候条件、3种天牛的生活习性并结合垂柳全年养护措施,开展以释放天敌昆虫的生物防治为主,园艺防治手法为辅的综合防治试验。结果表明:综合防治当年,根颈部星天牛、主干及一二级分枝云斑天牛和星天牛、顶梢桑天牛虫口减退率分别达到94.5%,98.4%和93.7%,且第二年防治效果基本保持。综合防治措施防治垂柳上3种天牛可弥补天敌防治的不足,且在有效杀灭天牛的同时保护生态环境。     

云斑天牛对永善县核桃危害程度分析

为了掌握云斑天牛对永善县核桃的危害程度,采用随机抽样的方法,按不同方位(东、南、西、北)、不同树龄及不同垂直高度等因子对云斑天牛产卵刻槽数量进行调查。结果表明,核桃林云斑天牛有虫株率50. 00%,每株平均产量17. 16粒,最高达74粒/株。1-6年生核桃幼树上无云斑天牛产卵刻槽,云斑天牛主要危害10-30年生核桃,82. 5%产卵量集中在距地面0-2. 0m的范围内,但云斑天牛在树干上产卵没有方向的偏爱。根据其产卵习性,可采用树干基部涂白,人工敲击产卵痕的方法进行防治。     

鄂北山区油桐云斑天牛的发生与防治

<正> 云斑天牛(Batocera horsfieldi Hope),鞘翅目,天牛科,又称白条天牛,群众称为大钻心虫。此虫近几年在鄂北山区油桐树上发生较为严重。因桐油是山区农民经济收入的主要来源之一,油桐树栽培面积逐年扩大,为云斑天牛提供了丰富的寄生条件;加之农民对此虫的为害认识不够,防治不得力,也间接地助长了云斑天牛的发生。分布及为害云斑天牛主要以幼虫蛀食油桐树主干木质部,轻则削弱树势,使树体生长发育不良,降低桐油的产量,重则导致整株树枯死。主干被蛀空的树极易被风吹折。除幼虫     

利用花绒寄甲防治杨树云斑天牛的研究

在湖南和湖北省选取9个云斑天牛危害的杨树林作为试验林,释放云斑天牛的寄生性天敌花绒寄甲卵和成虫开展生物防治云斑天牛试验.通过调查天敌释放前后被害株数和株虫口数2个指标对花绒寄甲的防治效果进行评价.结果表明:林间释放这种寄生性天敌的卵和成虫均对云斑天牛有良好的控制效果.在释放花绒寄甲卵的3个试验林中,平均株虫口校正减退率为83.27%;平均被害株校正减退率为74.33%;在释放花绒寄甲成虫的6个试验林中,平均株虫口校正减退率为84.23%;平均被害株校正减退率为75.65%.通过对释放花绒寄甲卵和成虫后当年和第2年调查的防治结果进行比较,表明释放天敌成虫的防治效果略好于释放卵的林分,但二者差异不显著.由于人工繁殖花绒寄甲成虫的成本远高于卵,因此,在生产中大面积防治云斑天牛时,采用释放花绒寄甲卵的方法比较经济.     

杨树蛀干害虫——云斑天牛

杨树蛀干害虫—云斑天牛徐素芬（江西省九江市林科所３３２００６）关键词：杨树害虫云斑天牛防治调查本世纪７０年代初引入我省的杨树无性系以其生长迅速、繁殖容易、材质优良、用途广泛深受群众喜爱,已成为平原滨湖水网地区主要造林树种。随着杨树日益广泛的栽植,其速...     

德阳市杨树云斑天牛发生情况及防治措施

自1999年至2003年连续5d对德阳地区杨树云斑天牛的发生、危害情况进行了监测、研究。弄清了云斑天牛的分布范围及特点，总结出了云斑天牛的生活规律、习性及对杨树的危害特性，并提出了针对性的防治措施。     

应用绿色威雷防治绒毛白蜡云斑天牛试验研究

云斑天牛(Batocera horsfieldi)是黄河三角洲广泛栽植的绒毛白蜡(Fraxinus velutina)最重要的蛀干害虫之一,其成虫补充营养期是防治的关键时期。应用绿色威雷(8%触破式微胶囊水悬剂)0.25%、0.33%、0.5%浓度的药液对绒毛白蜡云斑天牛成虫进行喷雾防治试验,以罩网法和地面法调查平均防治效果分别为90.7%和86.2%,防治效果非常显著,且特效期长达50d。     

杨树云斑天牛在贵州的危害

在查阅有关文献的基础上,结合多年从事杨树云斑天牛(Batocera horsfieldi Hope)防治的经验,概述了云斑天牛在贵州发生危害的特点,初步进行了成灾原因分析,并进一步展望了现有防治技术只能是短期内有一定效果,要达到对云斑天牛长期的可持续防控目的,应从造林设计阶段入手,适地适树,多树种的针阔混交,才能充分发挥营林措施,并积极应用综合治理技术。     

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。