贵州清水河自然保护区蝽次目区系初步分析

为弄清贵州清水河自然保护区蝽次目昆虫区系特征,通过实地调查和查阅资料,对保护区蝽次目昆虫区系进行了研究。结果表明,保护区共有蝽次目昆虫88种(亚种),隶属于12科62属,其中以蝽科种类最多,有40种,其次为缘蝽科,有19种,再次为猎蝽科,有10种。在世界动物地理区系中,东洋区成分显著,但具有较多古北区成分,东洋区-古北区共有物种占种总数37.5%,并杂有少量其他区系成分;在中国动物区系中,以西南区成分为主,但与华南区和华中区有较多共有成分,西南-华南共有种占81.8%,西南-华中共有种占76.1%。贵州清水河自然保护区蝽次目昆虫具显著东洋区特征和本区域独有特点。     

辨认蜻蜓

蜻蜓目昆虫在中国至今已记录到650余种,分为3个亚目:差翅亚目(狭义上的蜻蜓)、束翅亚目(蟌,俗称豆娘)和间翅亚目。差翅亚目常见类群有大蜓、蜓、春蜓、伪蜻和蜻,通常把这类称蜻蜓,它们的成虫体型一般较为粗壮,两复眼相接或分离,其间距小于单个复眼直径,翅基部较宽且后翅宽于前翅,停息时翅膀水平展开,有的种类会稍向下收拢。稚虫筒状或扁平,腹内具有直肠鳃。     

江西九连山国家级自然保护区蜻蜓资源调查初报

报道九连山自然保护区蜻蜓目昆虫43种,隶属于8科30属,其中江西新纪录5种;对该区内优势种和常见种作了记录;区系分析表明,九连山蜻蜓以东洋界为主,25种,占总数的58.14%,古北和东洋共有种13种,占总数的30.23%,广布种5种,占总数的11.63%。     

广东象头山保护区野生动物资源调查和保护对策

为掌握资源现状,受惠州市林业局委托,于1999年5～6月对象头山自然保护区的野生动物资源进行了综合考察,共发现野生动物203种,隶属4纲25目69科，其中两栖纲、爬行纲、鸟纲和哺乳纲分别有19、42、113和29种.东洋界种类占77.33%，动物地理区划属东洋界华南区闽广沿海亚区.国家一、二级保护动物分别有2和23种.最后分析了资源状况，并提出了保护对策.     

中国花蝽类昆虫动物地理学研究

对有较详细分布资料的20属93种花蝽类昆虫进行了分析.结果表明:中国花蝽类昆虫其区系组成以东洋界为主体,计33种,占总数的35.48%,跨古北、东洋二界24种,占总数的25.81%,古北界23种,占总数的24.73%;在世界范围内,中国花蝽类昆虫种的分布类型大致可分为5种,如中国特有分布型、世界性分布型、东亚分布型、古北和东洋界共有分布型、全北界分布型;在中国动物地理区划中,西南、华南两区分布的种类最多,合计占总数的32.26%,可见两区关系密切.     

飞动的“宝石”——蜻蜓

蜻蜒是指昆虫纲蜻蜓目所有种类,包括差翅亚目（蜻和蜒）、均翅亚目（蟌,亦称豆娘）和间翅亚目（我国没有,仅在日本和印度各发现一种）。目前,全世界已命名的蜻蜓约6000多种,我国有700余种。     

江西官山自然保护区昆虫区系分析

据有较详细资料的1498种昆虫区系分析,本区昆虫以东洋界为主体计901种,占总数的60.15%,古北界71种,占总数的4.74%,东洋、古北二界共有种328种,占总数的21.90%,本区昆虫属东洋界范畴;按中国动物区划分析表明,华中、华南、西南三区的昆虫亲缘关系最为密切;在我国东部地区,按长江、淮河、黄河等9条自然分界线,记述了官山产196种昆虫分布区的南北限.     

江西武功山国家森林公园野生动物资源及保护对策

为科学规划森林公园和促进生态旅游,科学保护和可持续利用旅游资源,作者于2001年7月中旬～8月上旬、2006年12月中旬,对武功山森林公园进行了为期20多天的陆生野生脊椎动物资源野外调查。调查得知：武功山森林公园现已知野生动物246种,录属4纲30目75科。其中两栖纲、爬行纲、鸟纲和哺乳纲分别有2目7科25种、2目10科37种、18目40科139种和8目18科45种。其动物地理区划属东洋界华中区东部丘陵平原亚区。动物区系组成以东洋界种类明显占优势,占总物种数的60.57%,而古北界种类占9.76%,广布种占29.67%。两栖纲和爬行纲的东洋界种类分别占92.00%和75.68%。整个动物区系表现为以东洋界华中区与华南区共有物种及东洋界华中区物种为主、南北成分混杂的区系特征。公园内有国家重点保护动物35种,其中黄腹角雉、白颈长尾雉、云豹、金钱豹属国家Ⅰ级保护动物;草鸮等31种属国家Ⅱ级保护动物。公园内野生动物及其生境受人类干扰破坏大,当地群众保护意识有待增强,故需加强野生动物保护、执法管理工作。     

柳叶马鞭草传粉昆虫的多样性研究

为减少森林害虫危害进而维持植物物种多样性，采用网捕法和观察法调查柳叶马鞭草Verbena bonariensis传粉昆虫的种类，对其进行多样性研究、区系分析、日间活动规律观察。结果表明：佳木斯地区柳叶马鞭草的传粉昆虫有4目7科18种，优势种为中华蜜蜂Apis cerana，占总数的53.1%。柳叶马鞭草传粉昆虫在东洋界和古北界的分布数量分别占11.1%,61.1%，东洋界和古北界都有分布的数量占27.8%；鳞翅目昆虫的多样性指数与均匀度指数最高，膜翅目昆虫的丰富度指数最高；传粉昆虫日活动规律中呈现单峰型和双峰型。     

福建雄江黄楮林自然保护区两栖动物研究

采用样线调查法,对福建雄江黄楮林自然保护区两栖动物资源及其地理区系进行调查分析。结果表明,两栖动物有2目7科30种,保护区两栖动物资源种类丰富,种群数量多,具有很高的保护价值;本区两栖动物地理区划属于东洋界华中区的东部丘陵平原亚区闽北山区丘陵地理省,华中向华南区系过渡性质明显,与台湾两栖动物关系密切,是戴云山脉两栖动物的重要组成。     

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.     

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 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.     

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.