花圣紫薇

人间六月芳菲尽，山上紫薇始盛开。紫薇花开的时候，远看，只见枝梢花穗累累，满树花团锦簇，彰显出热烈的气氛，宛如绚丽的云霞，灿烂无比。近看，串串花穗结满了许多圆如青豆的花蕾，有的青绿，有的绿里泛红，含苞待放。正在绽开的花蕾，花瓣攒聚着，皱缩着，活像一朵朵小小的康乃馨，已经盛开的花蕾，浅红色的花瓣向外飞扬，     

火力楠的栽培技术

火力楠（Michelia macclurei Dandy）]名醉香含笑，产于广西南部，广东东南部、南部，海南及越南北部，是世界珍稀优良树种。其树干通直，木材结构细，纹理直，切面装饰光滑美观，易干燥，有香气，少开裂，不反翘，为优良建筑用材，常用作楼梯扶手、车船厢板，也可作家具。树形美观，枝叶茂密，花白色，花期长，花多而密，有芳香，为优良的木本花卉、园林风景树、行道树。     

缙云山植物多样性概述

缙云山由于气候温湿，土壤肥沃，植物繁茂，物种十分丰富。根据最新调查、整理和统计数据，缙云山植物249科，966属，1915种（包括亚种、变种、变型）。其中，藻类植物2科，19属，105种，苔藓植物45科，77属，109种，蕨类植物38科，74属，153种，裸子植物7科，10属，46种，被子植物157科，791属，1502种。国家重点保护植物50余种（包括引种），中国特有属24属。植被类型多，有6个植被型，群系33个，群丛64个。这些数据充分说明了缙云山植物的丰富性和多样性。     

省委书记郭金龙强调领导干部一定要关注林业

3月1下午，省委书记、省人大常委会主任郭金龙，省长王金山，省委副书记、省纪委书记杨多良，省委常委、省委秘书长张学平，副省长赵树丛，省政府秘书长张俊等，来到合肥大杨镇国家林业科技创新基地参加义务植树劳动，与省委副秘书长、省委办公厅主任杨春光，省委副秘书长李祖顺，省委副秘书长、省委政研室主任张世平，省委副秘书长周光全，省政府副秘书长、省政府办公厅主任梁热，省林业厅厅长唐怀民，合肥市市长郭万清，省林业厅副厅长程鹏、赵波，     

紫枝玫瑰

紫枝玫瑰为杂交培育的新品种，因其枝条颜色为紫色而得名。紫枝玫瑰灌丛直立扩张，植株健壮，枝条下部直立，上部松散，多分枝；枝条紫红色，老枝颜色较深，当年生枝条为绿色。小叶椭圆形，叶轴及叶背面具白色绒毛，叶脉下陷明显，叶缘具大钝锯齿，新叶微曲，老叶平展。花大，重瓣，紫红色，有香气。结实能力强，不易感锈病。     

绿色儿歌四首

植树 蜜蜂唱，蝴蝶舞，春风吹拂万物苏。肩扛锹，手握锄，小朋友集队来栽树。深挖穴，细培土，认真植树不马虎。栽松杉，栽檫树，栽杨柳，栽法梧，栽山岗，栽公路，栽了一处又一处。     

投稿须知

1 来稿务求论点鲜明，论据可靠，数据准确，文字精练，内容科学、先进，实用，具有创新性。内容应注意保守国家机密，论文请按以下顺序书写：题目（不超过20个字为宜），作者姓名，作者单位及邮政编码，中文摘要，关键词，     

世外果园——北京永新源生态农业有限公司

北京永新源生态农业有限公司总占地面积近5000余亩，这里群山环绕，山青水碧，鸟语花香。树莓园里黑莓、红莓，黄莓相映成趣。林荫道上鸭群漫步，金鱼湖边怡情垂钓，丝瓜架下观鱼带玩，长城垛上引吭高歌。山路蜿蜒，惊诧于石碾，奇石如天工作；林果树下，掩映着躺椅，别墅如入人间仙境。鲜红的火枣，诱人的樱桃、育，李、桃、梨任你采摘，无穷乐趣，尽在其中。     

发展城郊林业 建设和谐黄州

黄州区地处黄冈市郊，总面积3.6万hm^2，总人口37.5万，是一个面积不大的平原湖区，近几年来，以实现黄州林业的跨越式发展，建设林业强区为目标，扬长避短，突出城郊生态建设和产业建设为重点，以林业工程项目为支撑，初步建立以扬树速生丰产林基地，水果基地，     

常春藤的栽培与应用

常春藤又称洋常春藤、长春藤，为五加科常春藤属多年生常绿藤本观叶植物，攀缘生长，常春藤是典型的阴生藤本植物，全是木质茎，茎长可达3～5m，多分枝，茎上有气生根。细嫩枝条被柔毛，呈锈色鳞片状，叶互生，革质，油绿光滑。叶有两型：营养枝之叶，呈三角形状、卵形或戟形，常三浅裂或全缘，长5～8cm、宽2～3cm；花果枝之叶，椭圆状卵形，全缘，叶柄细长。花为伞形花序，     

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.     

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.