齐齐哈尔市园林树木病害调查

对园林树木病害进行了系统调查,查清我市园林树木病害94种,为园林树木病害防治提供科学依据.     

树轮同位素古气候学研究(摘要)

<正> 1 研究原理、意义和现状树木的生长涉及一个吸收太阳辐射能以及CO_2和H_2O参与光合作用的过程。在这一过程中,树木体内的管状细胞发生分裂并重新生长,从而使树木不断增高和加粗。树轮是树木     

年轮:记载着环境变化的珍贵史料

在树木的横断面上,可见到许多深浅相间的同心圆环,这就是树木年轮。它不但可以告诉你这棵树的树龄,而且还给你带来自然界的丰富信息。目前,科学家已发现树木年轮具有天文、气象和环境科学的研究价值。如地震发生、火山爆发和环境污染等灾害,都能在树木年轮上记录下     

城市绿化

1.前言世界各国的美丽城市都有绿色树木装饰。城市绿色树木除有美化环境的作用外,还具有改善环境、预防风沙与水土保持等种种作用。城市环境与绿色树木的种植、管理的关系十分密切。城市环境大致分成自然环境与人为环境。影响城市树木的主要是自然环境。本文将论述自然环境与城市树木之间的关系。城市的自然环境是城市本身存在的条件。由于城市人口的密度的增大和城市建设的扩大,城市的自然环境正在     

工业废气--SO2的大气污染与树木叶片中叶绿素含量的关系

用分光光度法,对在工业废气SO2环境中生长的北方常见树木叶片中叶绿素含量的变化进行了测试.结果表明SO2的大气污染对树木有伤害作用,受污染的树木叶片叶绿素含量都明显下降,在SO2大气污染物污染的3种树木中其下降的幅度由小到大依次为旱垂柳、中东杨和白榆.这说明各种树木对SO2的大气污染伤害的反应不同,其抗性是白榆<中东杨<旱垂柳.     

如何提高城市植树成活率

近年来许多城市都在植树,但是新植的树木枯死的情况时有发生。这主要是对种植后的早期阶段缺乏必要的护理所致。绿化树木所需的基本条件是灌溉、施肥、修剪和防止病虫害。其中灌溉是最重要的不可忽视的一项。根据各地经验,城市树木光靠雨水是不能满足树木需要的,因为街道两旁只有树木四周土壤露出地面,难以使树木吸收到足够的水份。幼树每周至少需要二点五厘米降水量。如降雨不足,每周应浇水两次,每次水量约二十五至四十升,用十五分钟使水渗入根部区域。如土壤过便,应在温暖天气松土10厘米。     

水泥厂废气污染对绿化树木的影响

本通过对广州水泥厂厂区及周围绿化树木叶片含量，以及叶片干重、下表皮气孔密度、叶绿素含量等三项影响指标进行分析测定。并与对照点比较，综合反映水泥厂废气污染对绿化树木的影响．结果显示．绿化树木已产生明显的污染影响特征．这是环境多因子长期作用的结果，而水泥厂粉尘污染物是影响绿化树木的首要因素．     

树木千年不死之谜

此前,科学家曾在瑞典达拉纳省的山区发现了一棵母树的残桩上长出了一丛欧洲云杉,这丛云杉母树的年龄竟然高达9550年,真可谓世界上最长寿的树木. 为什么大多数树木的寿命只不过是几年、十几年、上百年,而有的树木却千年不死?什么样的树木才能长寿呢?这还要从它们本身说起.     

城市垃圾填埋杨植树造林试验研究

通过在青岛湖岛垃圾场的现场试验，研究了城市垃圾填埋场上植树造林的方法、适宜树种的筛选以及影响树木成活和生长发育的主要因素。结果指出，垃圾中有机质发酵所产生的甲烷气体是抑制树木成活和生长的关键因素。覆土层除为树木提供支持和生存环境外，还能阻挡甲烷气体的逸出，因此，土层越厚，越有利于树木成活和生长。还对１８种木本植物对甲烷气体的耐性进行了筛选。     

齐齐哈尔市园林树木害虫调查及无公害防治

对园林树木害虫进行了详细调查,查清齐市地区园林树木害虫共有6个目,23个科,55种.其中烟角树蜂、杨潜叶跳象、毛翅夜蛾为我市新记录种.并将园林树木害虫分为食叶害虫、蛀干害虫、地下害虫三大类,提出无公害防治对策.     

Public acceptance of tree health management: Results of a national survey in the UK

Assumptions about public stakeholder attitudes to pest and disease management can influence the decisions of forest managers and NGOs involved in responding to pests and diseases; however, they are rarely assessed directly. Evidence on the social acceptability of tree health management methods is required to inform government led policy and management. A nationally representative survey of 2000 members of the UK public was used to address two research questions: (1) How acceptable are tree health management methods to the public? (2) How do opinions about woodland functions, concern and awareness of tree pests and diseases, and demographics influence acceptance of management methods? We found that public stakeholders are highly supportive of tree health management; however, knowledge about tree pests, diseases, and management options is low. Methods seen as more targeted and ‘natural’ were preferred, e.g. felling and burning only affected trees and using biological control rather than chemical control. There were demographic differences in attitudes: men and older people are more likely to support management interventions and stronger management methods than females and younger people. Acceptance of management can also differ according to location and local context (e.g. management is less supported when it may impact on wildlife) and values (e.g. those with economic values are more supportive of management). These findings provide evidence to support current government initiatives on tree health and should improve confidence amongst managers tasked with carrying out tree pest and disease management. However, there is a need for in-depth qualitative studies to explain the beliefs which influence demographic variations in acceptance and the influence of concepts such as ‘nativeness’ and ‘naturalness’.     

树木健康与病虫草害的关系分析

本文论述了树木健康与病害、虫害、草害的关系。     

北京不同古树类型和级别对土壤物理性质的影响

以北京的代表性古树白皮松、侧柏、油松和国槐为研究对象,分析不同树种类型和不同级别古树土壤理化特性以及土壤理化特性之间的关系,以期为古树土壤健康评价和复壮管理提供科学的依据。研究结果表明:研究区土壤含水量为10.62%,容重为1.20 g/cm3,紧实度为3.94 kg/m2,土壤孔隙度、毛管孔隙度和非毛管孔隙度分别为20.72%、11.77%和8.96%,各指标都呈中等变异;在6个物理指标中,土壤紧实度、土壤含水量和土壤容重与其他几个物理指标相关性较高;不同树种类型和不同古树级别对古树土壤物理特性影响并不显著。     

基于决策树支持向量机算法的船用设备故障诊断

目的 提高船用设备的智能化水平,增强船舶的安全性、可靠性,对船上设备进行状态监测,并基于监测数据对设备健康状况进行评估,对可能存在的故障工况进行识别.方法 通过采集机舱内的振动数据,对数据进行预处理、快速傅里叶变换,提取1/3倍频带特征,将倍频带谱信号作为特征向量,利用支持向量机算法进行模型训练及分类.对于船上多种工况及可能存在的多种故障类别,采用决策二叉树方法,提出一种快速、准确的状态监测及故障诊断策略.结果 在实验室工况下识别准确率接近100％.结论 该方法能够对船用设备进行状态监控、故障诊断、健康评估等提供支持,为设备检修、传感器布置等决策提供依据.     

齐齐哈尔市乡土树种与行道树选择

本文叙述了齐齐哈尔市乡土树种的选择，并根据园林树种的功能配置选择行道树。     

不同收获与清林方式对杉木林养分的影响

对三代杉木林全株、全木和传统收获及传统和全木收获后火烧清理迹地林分营养元素变化进行了研究 ,结果表明 :杉木林采用全株收获和全木收获的营养元素损失量分别是传统收获的1 99倍和1 64倍 ;采伐剩余物火烧导致林地生态系统中N和P2O5 大量损失 ;采用传统收获及随后火烧清理采伐剩余物 ,N和P2O5 损失量比仅采用全株或全木收获的均高。若缩短轮伐期 ,则可能导致立地N和P2O5 的严重亏缺 ;全株或全木收获导致大量盐基离子移出林地 ,可能导致土壤较为严重的酸化趋势。     

基于地理信息技术的树种分布知识的挖掘与发现——以四川省石棉县为例

论文以四川省石棉县为例,对空间数据库支持下的树种分布知识的发现进行了研究。利用GIS技术建立相关空间数据库,主要有森林资源二类调查GIS数据库、树种GIS数据库,以及10 m分辨率的DEM、多年平均大于10 ℃的年积温和多年平均年降雨量等栅格数据库。利用GIS的叠加统计分析等方法,发现了各树种分布的的海拔、年平均大于10 ℃的积温、年平均降雨量等带谱知识。利用GIS的拓扑空间分析方法,挖掘了各树种间的空间配置知识。该知识可用于退耕还林、造林绿化中,因地制宜地选择树种,以及配置树种。该知识对于辅助数据协同下的各树种遥感识别也具有重要意义。此外,对其他区域也有示范意义。     

三氯氢硅储罐环境风险评价事故树分析

采用事件树和故障树分析方法,对三氯氢硅储罐风险事故源进行了定量和定性分析。事件树定量分析结果为：储罐一旦发生泄漏事故,三氯氢硅泄漏事故概率为6．16×10-6,火灾、爆炸事故概率为3．08×10-6,中毒事故概率为7．61×10-7。故障树定性分析结果为：三氯氢硅蒸汽与空气混合浓度达到爆炸极限事件的结构重要度最大,其次是三氯氢硅泄漏事件,再次是点火源及罐区存在冷却水事件。通过事件树一故障树分析,探讨了储罐泄漏的事故后果及火灾、爆炸事故的主要原因,并提出了相应的防范措施。     

Natural and effective control of air pollution through plants- studies on a tree species: Holoptelea integrifolia L.

Gaseous and industrial air pollution is a serious problem throughout the world. It affects human health and plants also face negative impact on their biochemical processes, ultimately exhibited in terms of reduction in various growth parameters. The effect of air pollution is being felt even in remote areas, because pollutants can be transported over long distances. It is well known that plants absorbs gaseous/particulate pollutants and help in controlling air pollution. In order to test Holoptelea integrifolia L. as an effective and natural means for controlling air pollution present studies were undertaken. It was observed that the tree species tolerate well various pollutants present in the air, so can be used as an efficient method for minimizing of concentration pollutants to a safer level into the environment.     

Expert risk perceptions and the social amplification of risk: A case study in invasive tree pests and diseases

The Social Amplification of Risk Framework (SARF) is often used as a conceptual tool for studying diverse risk perceptions associated with environmental hazards. While widely applied, it has been criticised for implying that it is possible to define a benchmark ‘real’ risk that is determined by experts and around which public risk perceptions can subsequently become amplified. It has been argued that this objectification of risk is particularly problematic when there are high levels of scientific uncertainty and a lack of expert consensus about the nature of a risk and its impacts. In order to explore this further, this paper examines how ‘experts’ – defined in this case as scientists, policy makers, outbreak managers and key stakeholders – construct and assemble their understanding of the risks associated with two invasive tree pest and disease outbreaks in the UK, ash dieback and oak processionary moth. Through semi-structured interviews with experts in each of the case study outbreaks, the paper aims to better understand the nature of information sources drawn on to construct perceptions of tree health risks, especially when uncertainty is prevalent. A key conclusion is that risk assessment is a socially-mediated, relational and incremental process with experts drawing on a range of official, anecdotal and experiential sources of information, as well as reference to past events in order to assemble the risk case. Aligned with this, experts make attributions about public concern, especially when the evidence base is incomplete and there is a need to justify policy and management actions and safeguard reputation.