广州园林博览会的历史成就及可持续发展

广州园林博览会自1994年起每年举办一次，是春节期间重要的花事活动和园林行业综合性竞赛活动，一直受到各界人士的好评。文章回顾了广州园林博览会的发展历程，重点介绍了2004年至2014年的展览主题、内容、规模等，分析了广州园林博览会对本地城市建设的影响，并探讨如何促进园博会健康、可持续发展。     

广州花文化品牌的对外宣传与展示——以广州第29届园林博览会为例

第29届广州园博会于2022年3月31日-4月2日顺利展出。因疫情防控要求,本届园博会以海心沙主会场线上云观展与珠江公园分会场线下开放相结合的方式同步进行,让全球观众“云”赏春光,领略春意(图1)。活动注重质量、彰显特色、传承经典,展示广州园林建设发展的新理念、新技术和新成果,呈现广州等大湾区城市建设风采和历史文化风貌,体现疫情中花城广州的温度。     

文化重构视野下广州城市公园的建设与发展

在岭南完成文化重构的历史进程中，岭南园林逐步由边缘走向中心，成为我国园林事业发展的引领力量之一。作为见证者和重要载体，广州城市公园在文化重构的过程中不断完善和充实自身，日益焕发新的生机。以文化重构为视角，重点研究了中华人民共和国成立70年来广州城市公园建设与发展的活态历程，联系不同时期的社会文化背景，总结并揭示社会文化发展与公园建设的内在关系。多元汇通的文化基底、与时俱进的时代政策以及务实求新的人文精神为现代岭南园林的发展道路指明了方向，为岭南园林地位的进一步提升增加了底气和信心。     

第二十八届广州园林博览会学生设计竞赛成功举办

值第二十八届广州园博会之际,为激发园林学子景观设计创新意识和实际建造能力,培养风景园林行业实践创新型人才,中国风景园林学会教育工作委员会、广州市林业和园林局、广东园林学会及华南理工大学建筑学院携手举办了以"湾区花开"为主题的广州园林博览会学生设计竞赛。本次学生设计竞赛于2020年10-12月开放方案征集,共收集到来自142所院校的494份学生作品,其中有14份设计作品突围进入最终评审。     

《北京园林》征稿启示

《北京园林》是北京市园林绿化局与北京园林学会联合主办的园林行业综合性期刊，也是园林学会的会刊。它集政策性、学术性、知识性、资料性为一体，主要刊登城市园林绿化、园林规划设计与施工、园林植物的引种与栽培技术、草坪与地被植物、园林生态、植物保护与病虫害防治、节水园林与节水技术（中水的应用、滴、喷灌技术等）、园林机械、园林古建、园林史志（园林历史和文化）、园林赏析和国外本行业相关领域发展的译文以及有关“新北京，新奥运”方面的学术论文、学术研究、学术动态、科研威果、技术经验、科普知识及相关信息等内容。欢迎广大读者踊跃投稿。     

书画传友情——粤澳共贺广东园林学会六十华诞

今年4月初、5月中,广东园林学会书画艺术专业委员会与澳门地区文化艺术学会进行了两地互访和友好交流。4月7—9日,澳门地区文化艺术学会一行13人在赵维富会长的带领下到访广州,祝贺广东园林学会成立六十周年暨相关综合文化艺术展开幕。广东园林学会领导彭承宜、书画艺术专业委员会主任莫广松及部分会员热诚欢迎接待了澳门地区嘉宾。在穗期间,粤澳两地妙手丹青进行了“湾区一家亲”书画雅集,参观了广州中国国家版本馆和南越国宫署遗址博物馆,游览了北京路文化步行街、从化流溪河溪头村旅游区,并就粤澳文化源流进行了交流探讨。     

从网络传播的角度看中国园林的发展

互联网的快速发展,给园林的发展带来了重大影响,网络传播已经成为影响中国园林行业发展的重要因素。本文通过分析网络传播给中国园林发展造成的传统园林的中断、外来园林的冲击以及对园林市场的影响等方面的困境,但同时也带来了文化碰撞促进新思潮的交流、公众参与使得园林品位的提升、先进技术带来设计语言的创新等机遇。阐述了网络传播下中国园林发展的主体方向应该是园林传统的继承、融入外来文化以及积极创新。提出要充分利用网络传播,参与世界范围的园林交流活动、开展国内相关学科技术交流、建立网络评论平台,加大群众监督反应的影响力、推广应用电子商务,促进园林产业的发展。     

《北京园林》征稿启示

《北京园林》是北京市园林绿化局与北京园林学会联合主办的园林行业综合性期刊，也是园林学会的会刊。它集政策性、学术性、知识性、资料性为一体，主要刊登城市园林绿化、园林规划设计与旆工、园林植物的引种与栽培技术、草坪与地被植物、园林生态、植物保护与病虫害防治、节水园林与节水技术（中水的应用、滴、喷灌技术等）、园林机械、园林古建、园林史志（园林历史和文化）、园林赏析和国外本行业相关领域发展的译文以及有关“新北京，新奥运”方面的学术论文、学术研究、学术动态、科研威果、技术经验、科普知识及相关信息等内容。欢迎广大读者踊跃投稿。     

纪念广东园林学会成立50周年系列报导

2012年11月17日是广东园林学会成立50周年纪念日,为此,学会于11月15日在广州中山纪念堂举行了一系列庆祝活动,包括庆典表彰大会,"传承岭南园林文化"和"创新岭南园林建设"两场论坛和文艺晚会。     

《广东园林》杂志2019年协办单位及编辑委员会全会成功召开

2019年7月23日《广东园林》杂志协办单位及编辑委员会全会在广州黄花岗公园会议室召开。《广东园林》杂志编委会常务副主任彭承宜,主编朱纯,编委白嘉雨、邢福武、陆琦等专家及协办单位代表与编务共28人参加会议。会议首先由朱纯主编作《广东园林》编辑部2018年至今的主要工作情况汇报。杂志始终关注行业理论、一线技术和管理创新等方面的文章和信息,追踪行业热点、亮点,丰富栏目及内容;报道协办单位动态信息,并为其提供先进项目及科研技术宣传的服务平台;持续加强自身建设,努力提升杂志质量,并通过与高校进行专题约稿、共办论坛等方式,扩大杂志的宣传、提升影响力等。     

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。     

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.     

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.     

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.