太原市居住区绿地植物应用与配置模式研究

以太原市绿化达标的40个居住区为研究对象,将居住区绿地分为公共绿地、宅旁绿地、道路绿地和配套公建绿地4类,对居住区内植物种类、植物配置、植物空间效果进行调查,总结归纳了植物组成与主要节点植物空间特征;采用层次分析法(AHP)构建太原市居住区植物配置适宜性与景观效果评价体系,并对45种植物配置模式进行评价。结果表明:太原市居住区绿地适用植物共有356种,绿地植物景观节点类型10类,绿地植物配置综合评价总体得分值较高,结合综合评价结果得出10种典型植物配置模式。     

河源市建成区城市绿地木本植物调查

调查了河源市4个绿地类型1163个样地木本植物状况,结果表明,共有木本植物78科227属401种(含种下单位),其中常绿木本植物为333种,占比为83.1%,木本植物以常绿为主;观花植物179种,占木本植物的44.6%,花色以红色、白色和黄色系列为主,花期集中在春、夏和秋三季。建成区城市绿地木本植物种类数在国内已有报道的城市中处于中游水平。绿地中频繁应用的植物种类仅30种,绿地景观多样性和植物多样性差。本地木本植物指数为0.86,达到了国家城市园林绿化的II级标准。     

太原市居住区绿地植物多样性特征及其与社会经济因素相关性研究

基于山西省太原市45个居住区绿地植物多样性调查,运用植物多样性指数及PCA主成分分析,分析居住区绿地植物多样性特征及其与社会经济因子之间的关系。结果表明,太原市居住区绿地中维管束植物146种,隶属于39科、73属,其中乔木101种,灌木45种。53%的居住区绿地中的乔木物种数为11～20种,而51%的居住区绿地中的灌木物种数为5种及以下,乔木物种的丰富度和均匀度均明显高于灌木物种。PCA排序结果显示,城镇居民人均可支配收入、城镇居民人均消费性支出及房龄是影响植物多样性水平的主要因子。     

无锡市公园绿地植物群落组成分析

利用植物群落学研究方法,在无锡市公园绿地设立了45个标准样地,对样地群落植物组成、植被类型、结构特征进行了分析。结果表明:所调查样地群落中共有维管束植物319种,隶属于103科235属,占无锡地区现有植物科、属、种的57.22%、26.02%、16.03%,江苏乡土植物203种,占总数63.6%;样地可分为7种植被类型:落叶阔叶型占35.5%、常绿针叶型占17.8%、常绿阔叶型占15.6%、常绿落叶混交型占11.1%、针阔混交型占6.7%、常绿落叶针叶混交型占2.2%;通过乔木层密度、灌木层重要值、乔灌木层树种组成、草本层植物组成分析等得出群落结构特征。最后提出无锡公园绿地植物群落植物组成优化建议。     

广东省河源市城区绿地彩叶植物资源调查及应用

为进一步掌握河源市城区彩叶植物种类、观赏特性及应用状况，对河源市城区主要公园、广场、单位、居住区、道路绿化等绿地开展实地调查。结果表明，河源市城区绿地彩叶植物种类较为丰富，共有62科108属149种，以乔灌木为主，有114种，占比76.51%；景观可持续时间长，全年有彩叶植物景观可赏；植物配置形式丰富多样，以基础种植、丛植、片植和列植居多。基于调查结果，提出河源市城区绿地应合理运用彩叶植物配植结构、增加乡土彩叶植物应用和加强养护管理等建议。     

太原市园林绿地植物种类及应用研究

对太原市133处有代表性的园林绿地的植物种类、数量、生长情况、病虫害等进行了调查，计有园林植物48科、100属、150种，其中常绿乔木9种、落叶乔木62种、常绿灌木5种、落叶灌木44种、藤本植物8种、多年生花卉15种、草坪草7种。在调查研究基础上，分析了太原市园林绿地植物应用方面存在的主要问题，提出了相应的对策建议。     

昆明金棱河公园植物群落结构调查

为了构建稳定合理的植物群落,更好地发挥城市公园植物群落的生态功能,采用取样方法对昆明市金棱河公园植物群落的物种组成、群落结构及其环境影响因子进行了调查。结果表明:金棱河公园植物以亚热带常绿阔叶林为主,地域特色明显,植物群落类型较丰富,但乔木层常绿植物配置密度过大,部分植物的栽植不符合其生态习性,未能发挥出植物正常生长所营造的景观水平;灌木层植物种类稍显单一,要形成更稳定合理的植物群落仍需要发挥乡土植物优势及后期良好的养护管理水平。     

宁波城市园林植物多样性调查研究

对宁波城市公共绿地居住区绿地、单位附属绿地、通道绿地等4类绿地进行了园林植物多样性调查。结果表明,宁波城市现有园林植物82科175属356种。植物种类在不同绿地上的水平空间分布格局为:公共绿地(274种)>单位附属绿地(202种)>居住区绿地(122种)>通道绿地(105种);从植物的垂直空间分布上看,乔灌木层植物具有较高的种类组成,而地被层的物种组成成分较低。植物群落配置以乔—灌—草结构为主(占73%),乡土植物种数仅占各种园林植物总数的26.9%。植物多样性综合评价指标排序为:通道绿地>公共绿地>居住区绿地>单位附属绿地,与物种丰富度Patrick指数(S)和Margalef指数(da)的排序完全一致。     

郑州城市园林植物群落物种多样性研究

采用典型抽样法,对郑州城市园林植物群落的种类组成和物种多样性进行了调查统计和分析。结果表明:1)3种不同类型绿地植物种类共计186种,隶属于72科133属;2)公园绿地的乔木层、灌木层和草本层物种α多样性指数均高于居住区绿地和道路绿地;3)公园绿地的β多样性指数均高于居住区绿地和道路绿地,居住区绿地和道路绿地之间的β多样性指数较小。针对郑州城市园林植物群落物种多样性的实际调查情况,提出加大乡土植物的运用,注意丰富季相景观和植物群落垂直结构层次的建议。     

沧州市公园绿地植物群落景观调查与评价

为了提升沧州市公园绿地植物群落的生态功能和植物景观效果,选择5个具有代表性的公园绿地作为研究对象,对其中应用植物的种类、生活型等进行调查,并构建植物群落景观综合评价体系,采用层次分析法(AHP)对选取的67个植物群落进行综合评价。结果表明,沧州市公园绿地应用的植物种类共计239种,隶属66科145属,其中乔木103种、灌木61种、草本51种、水生植物11种、藤本7种、竹类6种,灌木、草本、常绿植物、水生植物等应用较少;植物群落景观质量整体良好,Ⅰ级和Ⅱ级植物群落景观共52个,但优质植物群落景观相对较少,仅有4个Ⅰ级植物群落景观;根据存在的具体问题,提出增加灌木、草本及常绿植物的种类和数量,丰富植物群落层次,结合植物的季相变化、观赏特性及生态习性进行合理配置,加强对植物的后期养护管理等措施。     

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.     

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.     

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.     

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.     

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 Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.