广州城市园林绿地食源树种应用及其生态景观营造

【目的】城市鸟类及蜂蝶类群落结构多样性是城市生物多样性的重要组成部分和生态环境质量的重要评价标准之一。了解城市园林绿地食源树种的应用,探讨食源树种的生态特性及其景观特征。【方法】调查了广州市12处城市绿地食源树种的应用,观察鸟类及蜂蝶类的取食情况,记录绿地中食源树种的种类、应用频次、配置方式及生长状况,归纳分析食源树种群落构成、观赏特性、生态性等。【结果】广州园林绿地常见食源树种有23科33属45种,其中鸟类食源树种25种,蜂蝶类食源树种20种,以桃金娘科、桑科、大戟科为主,并以乡土种为主、外来驯化种为辅;食源树种的观赏与被取食时间主要集中于春夏季(31种),秋冬季的相对较少(16种)。【结论】广州市绿地的食源树种资源丰富,约300种,但常见鸟类及蜂蝶类食源树种仅占18%,结合良好适应性、抗逆性、取食性、观赏性,归纳出20种优势乡土食源树种;同时对食源树种群落组成结构进行分析,在兼顾食源树种的观赏性与生态性的基础上,设计出6组可在广州城市园林绿地推广应用的生态配置群落,采用树种混交与立体复合栽植的形式,乔、灌、草结合,形成丰富的水平与垂直植物群落结构,提高绿地生境异质性,增加食源树种的数量及丰富度,提供丰富稳定的食物来源,为鸟类及蜂蝶类提供多样的稳定栖息地。研究结果将对城市园林绿地食源树种的合理选择与科学配置应用,以及营造鸟类及蜂蝶类昆虫生态景观具有现实指导意义。     

仿刺参在实验性夏眠过程中消化道和呼吸树的组织学变化

将仿刺参Apostichopus japonicus分别在实验室15、20、25℃水温下进行培养,其消化道和呼吸树发生了退化现象,根据外部形态和组织结构变化特点,将夏眠退化过程分为早、中、晚3个阶段。夏眠退化早期,仿刺参可摄食,消化道开始缩小变细,组织结构出现退化现象;夏眠退化中期,仿刺参仍可少量摄食,消化道萎缩现象明显,组织结构退化较严重;夏眠退化晚期,仿刺参不再摄食,消化道萎缩成细线状,组织结构退化严重。呼吸树退化程度较消化道轻,表现为体积变小,但组织结构退化不明显。     

果树在居住区绿化中的发展前景

从生态、景观、人文等多方面阐述了果树在居住区中栽植的作用,讨论了果树在居住区的栽植前景。     

西尼罗病毒的基因进化分析

为更好的了解西尼罗病毒在世界各地的流行特征,从GenBank中随机选取45株西尼罗病毒的全基因或部分基因序列,进行同源性分析构建了基因进化树.发现西尼罗病毒可以分为两个谱系,1系病毒广泛分布在非洲西部、中东、东欧、印度、美国和澳大利亚等地,2系病毒分布在非洲亚撒哈拉、马达加斯加等地.1系的西尼罗病毒可进一步分为3个分支.对其中的22株西尼罗病毒部分基因序列进行同源性比较,发现1系病毒之间核苷酸同源在76.8%以上,氨基酸同源性在78.3%以上,而2系病毒与1系病毒核苷酸同源性约为64.7%～76.2%,氨基酸同源性约为64.7%～93.0%.     

矮化苹果树防风固定装置的设计

基于矮化苹果树的物理特征及生长条件,在传统用铁丝直接固定树干方法的基础上,设计了一种矮化苹果树防风防倒伏的调节装置。该装置能够有效地对树干进行固定,可防止矮化苹果树在刮风下雨等恶劣环境下发生大幅度摇摆,同时避免了传统方法中铁丝对果树的损伤以及倒伏对矮化苹果树根系造成的损伤。     

Geostatistical analysis to identify characteristics involved in sewer pipes and urban tree interactions

Tree roots cause significant and costly damage to sewer systems. However, the contributions made by tree and sewer characteristics to sewer system damage are not yet well understood. Previous research has proved inconclusive and there is a lack of agreement on the importance of the variables involved, which means that the results cannot be extrapolated globally. This study presents a methodology to improve the understanding of tree root-sewer conflicts through a geostatistical analysis of a tree inventory and CCTV video fault reports. The methodology is applied to a 11 km² case study in Bogotá, Colombia. The analysis used tree and sewer pipe georeferenced data, principal component analysis, and linear, Logit, and Poisson regression models. The proposed methodology identifies the pipe characteristics and the tree species most responsible for the root intrusion events into sewers. As expected, larger trees are prone to cause more pipe damage; therefore tree-pipe distance is a relevant parameter control for reducing potential deterioration. Cumulative precipitation and pipe length showed no effect on observed root intrusion events, and pipes made from brick had higher odds to present root intrusion in contrast with concrete pipes. The presented methodology uses readily available information and software, and can be modified depending on the requirements of each particular case study. This approach will therefore allow for more efficient use of costly, site-specific pipe investigations, and is especially useful for cases where there is a general lack of knowledge regarding the characteristics that favour the negative interactions between pipes and tree roots.     

武功山林场火炬松优树选择技术研究

以火炬松树高、胸径和材积为数量评价指标，结合冠形、侧枝角和侧枝粗度等形质指标，采用5株优势木对比法对火炬松人工林分开展优树选择研究，并根据分析结果制定了不同栽培密度下优树选择标准，符合该选优标准的候选优树有23株入选，总的入选率为48.94%。本研究制定的优树选择标准可为相似栽培密度的火炬松林分中优树选择提供了参考，选出的优树资源为火炬松种子园建设和育种群体的构建提供了优质材料。     

Adapting and applying evidence gathering techniques for planning and investment in street trees: A case study from Brisbane,Australia

Trees along footpath zones (or verges) grow on the “front-line” of urban forest ecosystems, increasingly recognised as essential to the quality of human life in cities. Growing so close to where residents live, work and travel, these street trees require careful planning and active management in order to balance their benefits against risks, liabilities, impacts and costs. Securing support and investment for urban trees is tough and robust business cases begin with accurate information about the resource. Few studies have accounted for spatial heterogeneity within a single land-use type in analyses of structure and composition of street tree populations. Remotely sensed footpath tree canopy cover data was used as a basis for stratification of random sampling across residential suburbs in the study area of Brisbane, Australia. Analysis of field survey data collected in 2010 from 80 representative sample sites in 52 suburbs revealed street tree population (432,445 ± 26,293) and stocking level (78%) estimates with low (6.08%) sampling error. Results also suggest that this population was transitioning to low risk, small-medium sized species with unproven longevity that could limit the capacity of the Brisbane’s Neighbourhood Shadeways planting program to expand from 35% footpath tree canopy cover in 2010, to a target of a 50% by 2031. This study advances the use of contemporary techniques for sampling extensive, unevenly distributed urban tree populations and the value of accurate resource knowledge to inform evidence-based planning and investment for urban forests.     

华木莲优株选育初报

为了选育出适应性强、生长量高的华木莲优良单株，通过20多年的华木莲良种选育工作，采用优势木比较法对野生华木莲进行调查选优，采种、育苗、子代测定、对比试验等工作，以地径、胸径、树高、保存率等生长量指标进行了分析，选育出了宜林科华木莲1号。采用杉木、木荷与宜林科华木莲1号子代进行造林对比时，10年生的华木莲林分的保存率、平均胸径、平均树高分别达到82.5%、11.8 cm、12.6 m，且林相整齐，表明1号优株的F1代林分为速生林分。24个引种点的适应性区域试验表明宜林科华木莲1号具有较好的适应性。     

High carbon losses from established growing sites delay the carbon sequestration benefits of street tree plantings – A case study in Helsinki,Finland

We assessed the net carbon (C) sequestration dynamics of street tree plantings based on 10 years of measurements at two case study sites each with different tree species in Helsinki, Finland. We assessed C loss from tree soils and tree C accumulation, tested the applicability of pre-existing growth and biomass equations against observations, and estimated the time point for the beginning of net C sequestration for the studied street tree plantings. The tree woody biomass C accumulation in the first 10 years after planting was 18–32 kg per tree. At the same time the C loss from the growth media was at least 170 kg per growth media volume (25 m³) per tree. If this soil C loss was accounted for, the net C sequestration would begin, at best, approximately 30 years after planting. Biomass equations developed for traditional forests predicted more stem biomass and less leaf and branch biomass than measured for the species examined, but total aboveground biomass was generally well predicted.