本文以生态经济型防护林为例,对“京九”铁路大兴段绿化模式的动力效应进行了研究。结果表明:对比旷野农田 (对照点),防护农田的风速平均约降低 18.9%,距林带树高 0.5倍距离处 (0.5H)风速的降低率可达 30.0 %左右,距林带 4H处至农田中心的风速降低率为 1.8%-7.1%,林带的有效防风距离至少可达 4H;防护农田内理查逊数 (Ri)总体平均值比对照点约高 4.6 %,动力速度总体平均值比对照点约低 14.7%。

运用分层随机抽样法,对福建省88个乡村的庭院林进行调查,结果表明:福建省乡村庭院林植物组成丰富,共计86科、186属、245种。按植物材料划分,种类和数量组成呈现乔木>草本>灌木>藤本的趋势;按村庄类型划分,种类呈现沿海型>平地型>半山型>山区型,植株数量分布呈现沿海型>平地型>山区型>半山型,植物组成以林果和观赏用途植物为主。出现频率较高的庭院植物有桂花、龙眼、榕树、桃树、柿树、梨树、棕榈等。相似度表现为乔木>灌木>草本>藤本,其中,平地型和沿海型乔木相似度最高。庭院林以乡土植物为主,外来植物仅占总体比重的16.17%,且以草本的比重最高,其次为乔木,而灌木和藤本比重相对较低。植物健康状况总体优秀,其中健康植物、正常植物和不健康植物所占比重分别为5.64%、89.72%、4.64%。庭院林近期种植植物数量比重仅占9.61%,其中,近期种植植物主要为乔木和草本,多以观赏型、食用性、名贵性为主。

By themeans of 3S techno logy, the landscape of B eijing was d iv ided into 6 primary landscape types and18 landscape patch types in the study, and a series of indexes w ere calcu lated by mode ls to analyze the spec ialstructure of Be ijing landscape. The results show: that the forest land is themax im al and basa l landscape patch type( area proportion is 42. 534% ), farm land ( 28. 888% ) and construction area ( 16. 639% ) are also the ma inlandscape types in B eijing. From landscape patch types and landscape patch catego ries levels, the landscape patchd istr ibuton is centralized, and patch shape is simple, the main landscape patch fractal d imension indexes are under1. 1, so urban landscape pattern is high ly influenced by human disturbance.

The research adopts open sampling method and TCT-GC/MS (Thermodesorption Cold Trap-Gas Chromatography/Mass Spectrometery) apparatus to collect and analyze the volatile organic compounds(VOCs) of Platycladus orientalis forest, with the intention of researching the compounds and diurnal variation of VOCs of P. orientalis forest in natural state in Beijing Western Hills in spring. The results are as follows: (1) There are 160 kinds (11 categories) of volatile organic compounds, containing Alkyl Hydrocarbon, Ketone, Alcohol, Acid, Aldehyde, Alkene, Ester, Aromatic hydrocarbon, Ether, Hydroxybenzene and Amide. The content of Alkyl Hydrocarbon, Ketone, Acid and Aldehyde occupy a greater percentage among all compounds. (2) The diurnal variation curve of total volatile organic compounds (TVOC) is characterized as "one peak at 11:00(36.44%) and one vale at 3:00(12.76%)". Generally, the concentration at daytime is higher than that of night, and higher in morning than in afternoon, with the maximum at noon. (3) The change of Alkyl Hydrocarbon concentration is greater in the morning and about midday, less in the afternoon and night. The diurnal variation curve of Ketone concentration appears as "three peaks and three vales". 1:00, 5:00—7:00 and 11:00 are peak time, 3:00, 9:00 and 17:00 are vale time. As to Acid, its concentration appears two obvious phases: the higher phase is from 9:00 to 17:00, with the maximum at 11:00, and the lower phase is from 19:00 to 7:00, with the minimum at 5:00. Concerning Aldehyde concentration, 17:00 and 19:00 are the higher phases and also has obvious difference with other time, while the lower phrase has no obvious difference with each other. (4) Alkene is the most important compound to human health. Its concentration appears as "one peak" at 15:00, which has obvious difference with other time. Totally, its content at daytime is higher than that at night, and higher in afternoon than in morning.

采用动态顶空吸附采集法对侧柏春季释放的挥发物(Volatile Organic Compounds ,VOCs)进行采集,同时利用Li-cor6400便携式光合系统测定仪测定其主要光合生理指标,分析了侧柏春季挥发物的主要成分、日变化规律及其影响因子。结果表明:(1)侧柏挥发物成分包括9类106种,主要挥发物成分是萜烯类化合物。对人体有益的有机挥发物包括萜烯类化合物、癸醛和乙酸乙酯,对人体有害的化合物包括三氯甲烷、笨和甲苯;(2)春季侧柏总挥发物(TVOCs)浓度日变化曲线呈"三峰两谷"型,5:00、13:00、19:00呈现高峰,凌晨23:00—1:00、下午17:00呈现低谷,对人体有益的成分出现在5:00、9:00、15:00、19:00,对人体不利的成分主要出现在中午15:00和夜间21:00—1:00且浓度较低;(3)温度较高、光照较强、湿度较低的时段总挥发物浓度总体较高,反之较低。蒸腾速率、净光合速率、气孔导度的日变化规律与总挥发物浓度日变化一致性较强。总挥发物浓度变化与蒸腾速率、净光合速率、气孔导度相关性极显著,与光照相关性显著,而与温度和湿度相关性不显著。

目的 研究森林空气颗粒物的不同高度垂直空间变化特征，为森林康养环境利用提供理论依据。 方法 于2017年5月对温州雁荡山杉木林林下（人体高度1.5 m）、林冠中部（6 m）及林冠顶部（12 m）3个高度的空气颗粒物质量浓度（TSP、PM₁₀、PM_2.5、PM_1.0）进行同步昼夜24 h监测，分析空气颗粒物质量浓度的空间变化规律。 结果 表明：（1）杉木林垂直空间不同粒径颗粒物的质量浓度存在差异，总颗粒物质量浓度与细颗粒物（< 2.5 μm）质量浓度在3种高度差异显著，均为林冠层最低；（2）3种不同高度的TSP、PM₁₀质量浓度日均值均达到二类环境功能区质量要求（300、150 μg·m^-3），其中，林冠层的TSP日均值达到一类环境功能区质量要求（120 μg·m^-3）；（3）不同高度各粒径空气颗粒物日变化规律大体一致，均表现为白天低，夜间高；（4）不同垂直高度空气颗粒物质量浓度，白天为林冠层最低；夜间为TSP质量浓度各垂直高度差别不大，PM₁₀、PM_2.5与PM₁质量浓度总体为在人体高度较低；（5）各粒径空气颗粒物与露点温度极显著正相关，与气压极显著负相关，其中，PM_2.5质量浓度与2项环境因子相关系数最大；除TSP外，其余颗粒物质量浓度与温度、最大风速极显著正相关，与相对湿度极显著负相关，各气象因子共同影响空气颗粒物质量浓度。 结论 通过对结果的综合分析，温州雁荡山杉木林环境林冠层为康养游憩最佳高度，最适宜白天出行。

目的 研究不同道路防护林的滞尘能力及滞尘的动态变化和空间分布规律。 方法 在春季对3种道路防护林(油松林、圆柏林、银杏林)距道路不同宽度的滞尘量进行连续观测，对比3种道路防护林滞尘能力，分析降雨、极大风速、相对湿度、PM₁₀等因子对滞尘动态的影响以及3种道路防护林滞尘的空间分布特征。使用单位叶干质量滞尘量(mg·g^-1)表征叶面滞尘能力。 结果 表明：(1)3种植物叶面滞尘能力差异显著，圆柏 > 银杏 > 油松，分别为4.79±0.20、2.48±0.07、1.42±0.04 mg·g^-1，单株和单位林分面积滞尘量均为圆柏林 > 油松林 > 银杏林；(2)3种道路防护林在外界影响下滞尘量处于动态变化之中，油松林具有比银杏和圆柏林更高的滞尘稳定性；(3)降雨量较低时3种道路防护林滞尘量均增加，降雨量较高时3种道路防护林滞尘量均降低，油松和银杏林的滞尘量更容易受降雨影响而降低；随着风速增大，3种道路防护林滞尘作用不断加强，风速继续增大时，油松和圆柏林滞尘量均有减少，银杏林滞尘量仍有显著增加。(4)3种道路防护林滞尘量在五环路侧(北)均高于香山路侧(南)，油松和圆柏林均呈现为道路防护林中间位置为最低点，银杏林中间位置滞尘量最高。(5)油松和圆柏林滞尘量外部比内部变化大，银杏林滞尘量内部比外部变化大。 结论 道路防护林的滞尘效益受树种、林分结构、所处环境、天气条件等多方面因素共同影响，在营建和管理过程中应充分考虑各种因素，充分发挥滞尘作用。

目的 研究北京海淀区3种道路防护林（油松林、圆柏林、银杏林）的滞尘能力、林内滞尘的空间分布规律、滞尘作用与气象因子和PM₁₀浓度的相关性。 方法 滞尘量的测定用单位叶干质量滞尘量（mg·g^-1）表征叶面滞尘能力。于冬、春、夏、秋4季对3种道路防护林内距道路不同距离处的滞尘量进行连续观测，比较3种道路防护林滞尘能力，分析3种道路防护林滞尘的空间分布特征及降雨等气象因子及PM₁₀浓度与滞尘作用的相关性。 结果 （1）3种道路防护林总体单位滞尘量圆柏林（4.20±0.19 mg·g^-1）>银杏林（1.98±0.07 mg·g^-1）>油松林（1.71±0.07 mg·g^-1）；油松和圆柏林的单位滞尘量冬季>春季>秋季>夏季，银杏林的单位滞尘量春季和秋季基本无差异，夏季最低；3种道路防护林的单位滞尘量在各季节均为圆柏林最高，银杏林次之，油松林最低。（2）3种道路防护林空间分布的总体特征为：油松和圆柏林的滞尘空间分布均表现为"两端高、中间低"，银杏林单位滞尘量林分中间位置略高于两侧；不同季节表现为冬季北侧高，春季南侧高，夏、秋季南北侧差异不显著。（3）降水量对3种道路防护林滞尘作用影响最大，是3种道路防护林滞尘的最主要限制因子，极大风速、气温、相对湿度和PM₁₀浓度对3种道路防护林滞尘均具有不同程度的正的直接作用。 结论 在相同配置模式（5 m×5 m）及林龄（18年）下，林地尺度滞尘量油松林最大、圆柏林次之、银杏林最低。道路防护林迎风一侧往往具有较高滞尘量，可根据盛行风向强化迎风侧的树木配置。降雨是树木滞尘的主要限制因子，冬季和春季降雨少，树木滞尘量较大，可结合人工冲洗措施使其发挥更大滞尘作用。

城市林业作为20世纪的新兴学科,自提出以来受到了世界范围的重视,并取得了令人瞩目的成就。进入21世纪,随着世界范围的城市化进程的加快,作为城市服务系统之一的城市森林的建设,在地域范围、主导功能、经营管理等方面将更加符合城市的发展需求,成为城市可持续发展的重要保障之一。本文重点阐述国内外城市林业发展的五大趋势,即突破城市建成区范围,向郊区扩展,辐射城市周边地区;追求城市森林布局与结构的自然化,实现城市与森林的完美融合;注重林水结合,发挥水体在改善城市环境的作用;强调以人为本,满足城市居民身心健康的环境需求;塑造城市文脉,升华民族城市森林文化。

The planting site, size, and health condition of street tree Ginkgo biloba in Beijing urban area were investigated and the influence factors were analyzed based on filed survey. The results showed that G. biloba were mainly planted in tree pit within strip planting median. The average height, diameter at breast height and canopy diameter were 8.11 m, 13.22 cm and 4.07 m, respectively, 82.9% trees were less than 10 m in height, and most G. biloba trees were still in the initial stage of height and diameter increment. The tree health status was described with three classes: class I (healthy), class II (fair) and class III (unhealthy). The percentage of class I, II and III for G. biloba trees in Beijing urban area accounted for 16.0%, 37.2% and 42.9% respectively. The results of analysis showed that the health status of G. biloba was associated with the site condition, tree size and management practices. The trees planted in urban forest patch grew better than the trees planted in green belts and tree pits; meanwhile, the bigger trees were healthier than the smaller ones. In addition, the effects of urban heterogeneous environment and human activities on the health of Ginkgo biloba were analyzed and the suggestions on management were launched.