北京7种园林植物及典型配置绿地用水量测算

用热扩散式边材液流探针(TDP)和盆栽法对北京7种常见园林植物的蒸腾用水量进行1个生长季的观测.结果表明:单株乔木(胸径15 cm左右)年用水量油松851.9 kg、侧柏982.7 kg、元宝枫1518.3 kg,元宝枫的用水量显著大于油松和侧柏;灌木单位叶面积年用水量大叶黄杨128.42 kg·m-2、金叶女贞117.28 kg·m-2、铺地柏82.38kg·m-2,铺地柏的用水量明显少于金叶女贞和大叶黄杨;6种典型配置绿地单位面积年用水量油松片林最少,为295 kg·m-2,金叶女贞绿篱最多,为1 083.2 kg·m-2.草地早熟禾纯草坪的用水量大于林下草坪,前者643.3kg·m-2,后者450.3 kg·m-2.纯草坪的用水量大于乔草型绿地,与灌草型绿地相差不大.     

古城保定呼唤绿地

古城保定呼唤绿地文／屈宏古城绿地知多少绿地，是城市绚丽多彩的衣装，更是建立高质量生态环境的重要保证。城市呼唤绿地，绿地为城市增姿添色；居民呼唤绿地，绿地给人们带来健康与安宁。城市绿化水平的高低已成为衡量城市现代化的一个重要标志。河北省保定市是有着悠久...     

对深圳特区园林建设问题商榷

保证绿地的合理分布和一定的绿地率,是建设花园城市的基础。深圳绿地规划能达到国家规范,但不够平均,罗湖区高楼林立,绿地甚少,要建设花园城市只有待将来拆除低层民房后的空地尽量留作绿地。现代化城市,要求所有功能区都有绿化用地,特区绿地已达18.6m~2/人,但因特区流动人口多,     

春到京城

正2018年,首都城市绿化建设再提速,大块绿地浓墨重彩、口袋公园清新怡人、城市森林充满自然野趣,北京城市环境在绿化美化中变得史加美丽宜居。2018年,全市全年完成"留白增绿"1600多公顷,建成丰台嘉囿、石景山何家坟等城市休闲公园28处、小微绿地和口袋公园121处,随着房山南水北调、通州凤港减河等111公里健康绿道的建成,全市绿道总里程已达到821公里,公园绿地500米服务半径覆盖率也由2017年底的77%提高到80%,而东城新中街、西城常乐坊等地新增的20     

京城的绿色新妆市民的生态福利

<正>北京市园林绿化局2017年的工作报告中给出了这样一个目标,今年全年,全市需要新增城市绿地600公顷,改造绿地450公顷,建设城市休闲公园15个、小微绿地50处,公园绿地500米服务半径覆盖率由72%提高到77%。然而随着北京城市建设的推进和人口增长,城区新增绿化面积变得越来越困难,城市绿地从何而来?这已经成为了越来越多北京市民好奇的问题。     

北京集水型公园绿地建设探讨

对北京城市水资源现状和园林绿地灌溉中存在的问题进行了分析。提出发展集水型公园绿地途径,包括:铺设生态型透水地面、收集道路雨水、收集公园建筑物顶的降水、收集和利用公园大型广场雨水以及利用山坡绿地、微地形绿地、公园林地进行雨水收集。对雨水收集和利用的方式进行了设计。     

韶关市区园林绿化现状评估

根据国家行业标准<城市绿地分类标准>,对韶关市各类城市绿地(公园绿地、生产绿地、防护绿地、附属绿地、其他绿地)进行了系统的介绍和评价.至2006年,韶关市辖三区总面积2800 km2,人口约90万.建成区面积78.3 km2,常住人口70.1万人,绿地总面积2412.77 hm2,人均公园绿地5.52 m2.指出公园建设与现代文明、历史文化和自然风貌的结合,是该市园林绿化的显著特点;带状公园的景观和社会功能已成为城市建设的亮点.提出切实抓好城市防护绿地规划和建设,对于韶关这个重工业性质城市,将具有战略性意义.     

城市闲置绿地的改造研究

通过对城市闲置绿地改造的实际设计案例,阐述了城市闲置绿地的弊端及城市闲置绿地改造的设计方法,探讨了城市闲置绿地转化为城市景观的过程中遇到的实际问题、改造过程中的成本控制、ESD在城市闲置绿地中的实际应用,为城市闲置绿地的改造工作提供参考。     

城市闲置绿地的改造研究

通过对城市闲置绿地改造的实际设计案例,阐述了城市闲置绿地的弊端及城市闲置绿地改造的设计方法,探讨了城市闲置绿地转化为城市景观的过程中遇到的实际问题、改造过程中的成本控制、ESD在城市闲置绿地中的实际应用,为城市闲置绿地的改造工作提供参考。     

北京城市公园绿地应急避险功能布局研究

为推动城市公园绿地应急避险体系建设的发展,在评价指标体系的指导下,应用GIS的空间插值技术,对北京城市人口统计数据进行了空间分布化,并通过人口密度分布与公园绿地缓冲区的叠加分析,对城市公园绿地的人口服务辐射能力进行了探索研究。结果显示,整个北京规划市区内公园绿地的缓冲区覆盖范围总计为421．96km^2,约占规划市区面积的38％,存在626．46km^2的服务盲区。另外,规划市区东部、北部和西南最外围区域大多数办事处中所含的公园绿地缓冲区占其行政区面积的比例均低于10％。在分析基础上,最终还进行了公园绿地应急避险功能布局的设想。     

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.     

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.