危害樱桃的一种新叶蜂（膜翅目：叶蜂科丝角叶蜂亚科）

记述丝角叶蜂亚科Ｎｅｍａｔｉｎａｅ实叶蜂属Ｈｏｐｌｏｃａｍｐａ一新种樱桃实叶蜂Ｈｄａｎｆｅｎｇｅｎｓｉｓ。本种危害樱桃严重。     

锤角叶蜂科两新种(膜翅目:锤角叶蜂科)

本文戾述分布于中国的锤角叶蜂科两新种：山楂童锤角叶蜂Ａｇｅｎｏｃｉｍｂｅｘｃａｒｔａｅｇｕｍ和人蒙古喜锤角叶蜂Ｐｒａｉａｎｅｉｍｏｎｇｇｕｎｅｎｓｉｓ。     

玫瑰栉角叶蜂生物学特性的研究

玫瑰栉角叶蜂生物学特性的研究刘岐，张秀丽，张凤兰，单丽华，于明拓（铁岭市林业局１１２０００）（辽宁省林业学校）（开原市林业局）玫瑰林角叶蜂ｔＣｌａｄｕｓＰｅｃｔｉｎｉｃｏ。ｌ’ｓ（Ｌ．》是玫瑰上的重要害虫之一。属膜翅目、叶蜂科、格角叶蜂属。目前国内尚...     

白桦锤角叶蜂生活史及生物学特性研究初报

白桦锤角叶蜂生活史及生物学特性研究初报谢宝贵，邢义，邢英明，于明山，韩梅，孙忠强白桦锤角叶蜂是呼盟免渡河林区的主要害虫之一，近几年来为害特别严重，被害株率９０％以上。白桦锤角叶蜂（Ｃｉｍｂｅｘｂｅｔｎｌａｒｉｓ）属于膜翅目广腰亚目锤角叶蜂科，主要分布...     

童锤角叶蜂属一新种(膜翅目:锤角叶蜂科)

记述了采自甘肃天水市膜翅目Hymenoptera锤角叶蜂科Cimbicidae童锤角叶蜂属Agenocimbex RohWer的一个新种－榆童锤角叶蜂A.elmina sp.nov.。     

伊藤厚丝叶蜂的初步研究

伊藤厚丝叶蜂的初步研究朱传富，杨文学，王金国，王成凯，杨伟林（黑龙江省苇河林业局林木种子园）（兴隆林业局）伊藤厚丝叶蜂是危害落叶松针叶的一种新害虫。１９８５年８月中旬在黑龙江省苇河林业局冲河经营林场发现，１９８６年７月经中国林业科学院昆虫室的叶蜂研究...     

介绍两种新森林害虫

本文介绍两种新森林害虫，其一，海南木莲枝角叶蜂ＣｌａｄｉｕｃｈａｍａｎｇｌｉｅｔｉａｅＸｉａｏ在海南省尖蜂岭危害海南木莲ＭａｎｇｌｉｅｔｉａｈａｉｎａｎｅｎｓｉｓＤａｎｄｙ，另一，厚朴枝角叶蜂ＣｌａｄｉｕｃｈａｍａｇｎｏｌｉａｅＸｉａｏ在四川省开县危害厚朴ＭａｇｎｏｌｉａｏｆｆｉｃｉｎａｌｉｓＲｅｈｄ．ｅｔ．Ｗｉｌｓ．两种害虫均属膜翅目，叶蜂科，粗角叶蜂亚科，英文稿件于１９９４年发表于北京林业大学     

甘肃叶蜂种类调查及分类研究 Ⅲ.锤角叶蜂科属种名录

整理采自甘肃膜翅目锤角叶蜂科标本总计64号,经鉴定分为6属16种。其中,细锤角叶蜂属7种,丽锤角叶蜂属2种,丑锤角叶蜂属3种,童锤角叶蜂属2种,唇锤角叶蜂属1种,毛锤角叶蜂属1种;包括1新属:唇锤角叶蜂属,4新种:辛氏细锤角叶蜂、中华童锤角叶蜂、多毛唇锤角叶蜂、甘肃毛锤角叶蜂,1中国新记录种:多环细锤角叶蜂,9甘肃新记录种和2已知种。     

鞭角华扁叶蜂滞育期幼虫空间分布型及抽样技术研究

鞭角华扁叶蜂滞育期幼虫空间分布型及抽样技术研究＊郑永祥崔相富吴道圣杨胜利陈绘画关键词鞭角华扁叶蜂、滞育期幼虫、空间分布、抽样技术鞭角华扁叶蜂［Ｃｈｉｎｏｌｙｄａｆｌａｇｅｌｉｃｏｒｎｉｓ（Ｆ．Ｓｍｉｔｈ）］属膜翅目（Ｈｙｍｅｎｏｐｔｅｒａ）、扁叶蜂科...     

黑角翼丝叶蜂的初步研究

黑角翼丝叶蜂Ｐｔｅｒｏｎｉｄｅｄｍｅｌａｎａｓｐｉｓ（Ｈａｒｔｉｇ）在山西省长治市一年发生２代，以老熟幼虫在土中结茧变为预蛹越冬。冬季和春季干旱是该虫大发生的主要因素，采用７１４烟雾剂或树冠喷洒４０％氧化乐果等农药防治，均能取得较好的效果。     

落叶松丝角叶蜂的生活习性及防治

１９９０年以来,落叶松丝角叶蜂在山西省太行山林局为害落叶松林,以幼虫取食当年嫩叶。该虫一年发生一代。６月下旬老熟幼虫吐丝下垂在枯枝落叶层内结茧越冬。翌年４月下旬开始化蛹,５月上旬至６月上旬陆续羽化,５月中下旬为产卵盛期,５月下旬至６月上旬为卵孵化盛期,防治试验结果表明,６月上旬,以林丹喷粉,幼虫死亡率可达９５％以上,见效快,且经济。     

河曲丝叶蜂的防治方法

简述了河曲丝叶蜂的形态特征和生物学特性,提出了防治河曲丝叶蜂方法。     

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.