海南尖峰岭国家森林公园古树现状调查分析

根据古树现状调查统计,尖峰岭国家森林公园共有古树2134株,隶属30科55属72种,属于一级古树的有41株,二级古树的有125株,三级古树的有1968株。其中,珍稀濒危的古树共有13种,隶属10科13属13种。古树种类组成以壳斗科等5个科占优势,从科的种类组成和树种的株数比例来看,古树分布趋向于大科和主要树种集中;一级和二级古树所占比例较低,符合森林公园以天然次生林为主的森林类型特征。并对此提出相应保护建议。     

南岳衡山古树名木资源现状及特征分析

以查阅档案资料和路线调查相结合的方法对整个南岳衡山自然保护区的古树名木资源进行调查。调查结果显示:南岳衡山有古树名木46科83属124种4 816株,其中古树4 772株,名木44株;树龄中以100~299年的古树最多,有4 595株,500年以上的古树有24株,最大树龄达669年;南岳衡山的古树大都分布在寺庙、道观内或附近的原始天然林中;从所有权来看,南岳衡山的古树名木国有4 727株,占98.15%,集体60株,占1.24%,个人13株,占0.26%,其它16株,占0.33%;从生长状态来看,南岳衡山古树生长为"旺盛"的4 110株,占86.12%,生长为"一般"的440株,占9.22%;从分布型来看,南岳衡山的古树名木划分为6个分布类型,6个变型(不含世界广布型);南岳衡山古树名木种的分布类型以中国特有分布为主,有62种,占种总数的50.4%,非中国特有分布中,温带分布最多,热带分布次之,种一级水平上南岳衡山古树名木具有亚热带性质,是华东植物区系的组成部分,在地理成分上与华南、华中区联系密切。     

泰山古树衰弱死亡原因及保护措施

据调查,泰山现有古树总数为18 198株。其中,正常古树占25.4%,轻衰和中衰古树占古树总数的63.7%,重衰和濒危古树所占比例为9%,死亡古树比例达到1.3%,急需保护古树935株。对187株死亡古树的死亡原因分析结果表明,古树自然死亡比例为2.7%,病虫害致使古树衰弱死亡比例为42.8%,工程建设破坏(建筑施工、修路、水泥硬化等)致死比例为25.7%,污水污物(厕所污染,建筑、生活垃圾)致死比例为8.6%,郁闭致死比例为6.4%。分析查找古树衰弱及死亡原因,采取相应的古树保护措施至关重要。       

东莞市古树名木无损诊断和健康评价

研究基于无损检测技术,用整体状况、树冠、树干、根部4个方面共14个指标,对东莞市50种、208株古树名木进行健康诊断.结果 表明,调查的古树名木整体表现良好,大部分树种其树势旺盛,树干无倾斜和偏冠或倾斜角度较小;受枝叶病害、虫害、寄生及树干病虫害的影响较小;枯枝、腐枝、顶梢枯死、叶斑、变色等发生率较大;树干洞穴、树体空洞、树干损伤、根部损伤严重,根部通水透气性差.     

江苏地区古树健康评价体系构建研究

通过实地调查评估、生理生化指标测定、树干无损检测等方法,结合文献查阅、专家咨询等途径,筛选出适用于江苏地区的古树健康评价核心指标,构建古树健康评价体系。结果显示,实地调查评估法和树干无损检测法确定的各项指标能够真实反映古树健康状况;生理生化指标测定法则建议在古树应急诊断中使用。依据建立的古树健康评价体系对溧阳地区21株古树的健康状况进行评价,应用效果良好。     

京都古树群

北京,这座历时三千多年的古城,为我们留下许多古树,这些古树不仅是历史的见证,还以奇绝苍健的千姿百态,形成独特的群落景观。 北京古树群落最为集中的是香山,共有古树五千多株,占北京市区现有古树总数的26％,以松柏为主,间有国槐、银杏,     

地坛 四季

北京地坛,又名方泽坛,始建于明嘉靖九年(1530年),为北京五坛中的第二大坛.坐落在安定门外东侧,与天坛遥相对应,与雍和宫、孔庙、国子监隔河相望。地坛是一座庄严肃穆、古朴幽雅的皇家坛庙,是明清两朝祭祀"皇地祇神"之场所,也是中国最大的"祭地"之坛。地坛内有大片空地,现有树木3.6万多株.草坪8.2万平方米,200年以上树龄的古树就有174株。地坛方泽坛外的三株古柏坡有特色,被     

洛阳市古树名木资源调查分析

采用实地现场调查为主,并结合访问当地群众的方法,以县(区)为单位,对洛阳的古树名木进行了逐株普查。结果表明:洛阳各县(区)古树种类数和株数有较大差异。全市古树共计86263株,名木69株,古树群213个,其中,散生古树9303株,隶属38科、84属、134种,树龄为100~299年、300~499年和500年以上的古树分别有6567株、1780株和956株。84.45%的古树表现生长势正常,衰弱植株和濒危古树分别仅占总数的10.70%和4.85%,死亡古树60株。根据调查结果,对洛阳古树名木资源现状、存在的问题进行分析总结,提出了科学保护措施,为加强古树名木的保护提供参考。     

广西北海市古树名木资源特征分析

对北海市古树名木资源现状进行了调查分析。结果表明:北海市共有古树名木1 299株,其中,一级古树8株,二级古树14株,三级古树1 273株,名木4株;树种31种,隶属于18科26属,株数最多的前5科为桃金娘科(Myrtaceae)、桑科(Moraceae)、樟科(Lauraceae)、无患子科(Sapindaceae)、木兰科(Magnoliaceae),树种以红鳞蒲桃(Syzygium hancei)株数最多;重点保护植物有4种,共84株,占总数的6.47%;生长状态以群状为主,占总株数的84.68%;权属以集体的最多,占91.38%;绝大部分古树名木生长于农村,占总数的92.22%,大多保存于风水林中。     

政和县古树名木资源特征分析及保护策略研究

以政和县古树名木为研究对象,政和县现有古树名木2768株,其中散生古树名木719株,古树群156个2049株,隶属21科35属45种,一级、二级、三级保护古树的数量和占比分别为137株占比4.95%、921株占比33.27%和1710株占比61.78%,在全县的10个乡镇(街道)均有分布,海拔501～1000 m内古树数量有1484株占总数的53.61%,树高主要集中在20～30 m内,胸围以200～300 cm为主,现有古树名木较差株和濒死株总量达53株占比1.92%。结合传统分析方法,利用Excel和ArcGIS10.2分析工具,分析了政和县古树名木的资源特征和空间分布规律。结果表明：政和县古树名木数量多、区系分布明显、树种多样,珍稀濒危树种丰富,空间分布呈现强变异的聚集性分布状态。针对政和县古树名木资源特征和研究分析结果,提出了具体的保护策略与建议,可为政和县的古树名木保护利用、森林生态旅游、乡村振兴规划提供参考。     

Effect of thinning on the development of compression wood in stems of Corsican pine

This study considered the effects of thinning on the development of compression wood in stems of 35-year-old stand of Corsican pine (Pinus nigra L.). Part of the stand had been thinned at 5-yearly intervals and part left unthinned. Twenty trees each from the thinned and unthinned stands were randomly selected and felled. Measurements were made on tree height, stem diameter, stem slenderness and canopy depth. Wood samples were removed from the central part of the main log and cross-sectional measurements made on ring width, basic density and compression wood content. Cross-sectional area of compression wood was found to be three time higher in stems from the unthinned trees in comparison with those from the thinned trees. No significant differences in mean radial ring width or basic density were found between treatments. Correlations indicated that, with increasing in stem diameter, compression wood content increased in the unthinned trees, while a decline in compression was observed in the thinned trees. Tree height was also positively correlated with compression wood content in unthinned trees, while no equivalent relationship was observed in thinned trees. Observations from this study, while not conclusive, suggest that phototropic stimulus may be producing stem inclinations in the unthinned stand as trees compete for space in the canopy, whereas crown competition has been largely eliminated in the thinned stand; and that this is responsible for compression wood levels recorded in this study.     

北京地坛公园古侧柏土壤理化特性研究

以北京地坛公园古侧柏为研究对象,采用环刀法和烘干法分析了北京地坛公园古侧柏土壤理化特性。结果表明:1)古侧柏土壤含水量为14.54%;2)土壤容重为1.59 g/cm3;3)土壤的总孔隙度、毛管孔隙度和非毛管孔隙度分别为26.86%,40.14%和13.28%;4)土壤紧实度为0.51 kg/m2。     

Influence of initial planting spacing and genotype on microfibril angle,wood density,fibre properties and modulus of elasticity in Pinus radiata D. Don corewood

Pinus radiata D. Don trees from six clones, grown at initial spacings of 2500 stems ha⁻¹ and 833 stems ha⁻¹ were destructively harvested. For these trees wood properties were measured on radial slices sampled at a height of 1.4 m above the ground. Relative to wide spacing, close initial stand spacing significantly reduced microfibril angle (MFA) and ring width and significantly increased dynamic modulus of elasticity (MOE), fibre length, latewood percentage and cell wall thickness. Density and fibre width were not significantly different between spacing treatments. Examination of the influence of genetic population on wood properties indicated that genotype significantly influenced MFA, MOE and ring width. The key wood properties MFA, MOE and fibre length were regressed against tree diameter, height and stem slenderness. All three wood properties were most strongly correlated with stem slenderness. Multiple regression models developed for MFA, MOE and ring width accounted for respectively 62%, 81% and 58% of the variation in these variables. The following changes occurred in sampled properties with increasing ring number: MFA and ring width declined markedly; MOE and fibre length increased markedly; latewood percentage and cell wall thickness increased slightly; and density and fibre width did not show any radial trend.     

肇庆高新区道路绿化调查及其优化对策研究

文章调查了肇庆高新区道路绿化的19个样地,结果显示,园林植物共计56科106属148种,其中,乡土树种共计26种;乔木、灌木、草本之比为2.96：2.48：1;常绿与落叶植物比例,乔木层为2.23：1,灌木层为6：1;观花、观果、彩叶植物分别占42.6%、6.1%、18.9%;植物种植形式以自然式种植为主,垂直结构主要有3种类型。在此基础上,探讨了道路绿化优化的策略,建议加强绿地规划布局的科学性,构建多种景观类型;丰富植物种类,确定园区27条主要道路的主调树种,做到“一路一树一景”,为该区道路绿化建设提供参考。     

Basic density,longitudinal shrinkage and tracheid length of juvenile wood of Picea abies (L.) Karst

Variation in the growth ring width, basic density, longitudinal shrinkage and tracheid length was investigated in the juvenile wood of Norway spruce samples taken from different heights in the stem. Annual height increments were cut from the ten youngest shoots from trees of three different heights. By this method the properties of an individual growth ring could be analysed without taking samples from each ring. Sixteen tree tops of an average stem height of 8, 15 and 25 m were analysed. Basic density was low in the first shoot, highest in the second or third one and decreased gradually thereafter. Longitudinal shrinkage was highest close to the pith and decreased to about 0.2% in the outer rings. Tracheids were only ca. 1 mm long close to the pith and their length increased sharply towards the tenth shoot. The properties of juvenile wood varied with the height in the stem. Longitudinal shrinkage around the pith seemed to increase with increasing height and basic density was highest at 25 m stem height. The applicability of the method for the calculation of basic density and tracheid length in individual growth rings close to the pith is discussed.     

保定市环城路绿地植物群落结构分析

为了认识保定市环城路绿地绿化结构特征,进而为保定市环城路绿地的建设提供指导和依据,采用抽样调查的方法,对保定环城路的树木进行了每木实地调查,对保定环城路绿地树木的种类组成、高度、径阶等结构特征进行分析.结果表明:15种主要树种占树木总量的60.24%.其中大约71.5%的树木属于小径木(胸径<10 cm),表明保定市环城路绿地绿化总体水平不高,有待改善.     

Characterization of Douglas-fir grown in Portugal: heartwood,sapwood, bark,ring width and taper

Douglas-fir (Pseudotsuga menziesii) is one of the best timber conifers providing long sawnwood components. Original from North America, it has been planted in Europe on approximately 550 thousand ha. Twenty Douglas-fir trees growing in two sites in Portugal were studied regarding ring analysis, heartwood, sapwood and bark development, and taper. The radial growth rate was 7.1 and 6.6 mm year⁻¹ at stem base for 45- and 50-year-old trees, respectively, in the two sites. Initial growth rate was slower, increasing until about 20 years and decreasing afterwards. Heartwood proportion represented on average 49% of the cross section in the lower part of the stem and decreased upwards. Heartwood formation was estimated to start at a cambial age of 8–9 years and increasing by 0.7–0.9 rings year⁻¹. Sapwood width was on average 75 mm at stem base, decreasing upwards. Bark was 26–27 mm thick at stem base, where it represented 15% of the cross-sectional area and decreased to 3–5 mm at the top. Stemwood and heartwood tapers were on average 15 mm m⁻¹ in the lower stem part and 21 and 18 mm m⁻¹, respectively, in the upper part. Douglas-fir showed a good potential for the mountain areas of Portugal, and under the silvicultural conditions of both stands the trees presented ring homogeneity, small conicity and low taper suitable for long wood components.

     

北京市六环内城市道路附属绿地木本植物多样性及结构特征

【目的】探讨北京市六环内城市道路附属绿地木本植物多样性以及结构特征,梳理北京市城区道路绿化建设现状,探索北京市城市道路附属绿地存在的问题及梯度变化规律。【方法】以0. 5 m的World View 2遥感影像为基础,目视解译北京六环外1 km范围内道路,以每种类型道路总长度的10%作为调查长度,利用Arcgis对该范围已命名道路随机选取实地勘测路段,调查选取路段木本植物树种、胸径、冠幅等指标,并对调研数据进行多样性及结构分析。【结果】本研究共记录北京市道路附属绿地木本植物33科、61属、77种,其中乔木59种、灌木15种、藤本3种;使用数量最多、频度最高的树种为国槐;北京本地种62种;植物丰富度、多样性指数均沿环路呈现了由城内向城外逐步增加的变化趋势;乔木平均胸径24. 07 cm,平均胸径沿环路由内向外逐渐减小,胸径等级分布在Ⅱ级数量最多;径级较大的树木占比由城内向城外逐渐减少,国道与胡同较大径级树木比例高于其他类型道路;乔木平均冠幅6. 33 m,Ⅳ级冠幅即6～8 m最为常见;各环路间冠幅由城内向城外逐渐减小,国道与胡同大冠幅树种占有较大比例。【结论】北京市道路绿地的物种多样性不高,优势树种优势度过强,尤其是北京市市树国槐,无论在数量上还是使用频率上都远高于其他树种;在乔木树种中,青年期占比较高,分布不均匀,幼年期树种过少;整体树冠覆盖较好,冠幅分级分布均衡;北京市道路绿地受城市化进程影响明显,沿环路由城内向城外显示出物种增加、胸径和冠幅减小的梯度变化;城市道路(环路、主干道、次干道、支路、胡同)物种丰富度明显高于公路(高速公路、国道、省道),大径级树木多分布于国道与胡同,公路冠幅大于城市道路。     

Timber quality after thinning from above and below in stands of Pinus sylvestris

Timber quality and logging damage after different thinning types in Scots pine (Pinus sylvestris L.) stands were studied in a field experiment in north Sweden. Thinning operations were mechanized and carried out according to normal Swedish practise. The treatments were thinning from below and thinning from above. The quality of the residual stand was evaluated using variables such as diameter of the thickest branch, stem taper, annual ring width, straightness and lean of trees. The only variables showing differences between treatments were lean of tree and stem straightness. No difference in the frequency of trees with logging damage was found. The conclusion of this study is that differences between thinning types in first thinning may be evened out when carried out as in commercial forestry due to extraction of strip road and damaged trees. Consequently, differences in timber quality and logging damage in the residual stand may be small.     

基于激光雷达技术的郑州市行道树空间围合度研究

行道树作为城市道路空间的重要组成部分,对于提升城市道路品质和改善道路空间宜人度发挥着重要作用。选取郑州市作为研究区域,基于激光雷达技术,对道路及行道树样本进行定量化调查分析,利用宽高比、树冠占有率以及天空视图3个指标对行道树空间围合度进行研究。结果表明,样本行道树的平均宽高比为3.21,平均树冠占有率为30.83%,平均天空视图数值为0.43。其中,影响空间围合度的因素主要有道路宽度、道路等级、道路板式。研究结果将为城市行道树空间结构的优化及调控提供科学依据。