北京市5种典型城市绿化植物的生态保健功能分析

城市绿地的建设在关注实用性、美学性的基础上，逐渐向关注生态保健效益的方向转变。试验针对目前关于典型的园林绿化树种的生态保健功能的研究较少的情况而展开。通过在奥林匹克森林公园、紫竹院公园、天坛公园这些北京市人流量大、典型的城市绿地中选取5种典型城市绿化植物作为试验对象，在不同空间以及不同的季相条件组合下，对形成绿地保健功能的空气负离子浓度、空气温度、湿度、二氧化碳浓度、噪音等因子进行研究。结果初步显示，乔灌草结构的绿地类型较其他乔木纯林有更好的生态保健功能，从相同季节、不同林种绿地的CO2浓度随时间的半日变化特征来看，乔灌草结构绿地的最大φ(CO2)为435×10-6，小于杨柳林451×10-6、杨树林488×10-6、侧柏492×10-6、油松614×10-6和草坪635×10-6；相对于常绿针叶树种，落叶树种在有叶期有较好的生态保健功能，以相同季节、不同林种的绿地的空气负离子浓度为例，旱柳林的负离子浓度为1500个/cm3，杨树林为1300个/cm3，侧柏林1300个/cm3，均高于油松林的750个/cm3；以侧柏为代表的常绿针叶树种较落叶阔叶树种有更稳定的生态保健功能，以有叶期和落叶期林内空气负离子浓度之差的平均值为例，杨树林林内空气负离子之差的平均值为301个/cm3，而侧柏林林内空气负离子浓度之差的平均值为154个/cm3。本研究获得的数据支持了城市绿地生态保健功能理论，可为合理设计城市绿地增强其生态保健功能提供了依据。

Analysis on the Eco-health Function of Five Typical Urban Green Species in Beijing

Having made considerable progress in recent years, the urban forestry construction is gradually transforming its concerns from focusing on function and aesthetics to eco-health function. Due to the lack of researches on the eco-health function of most-used plants species, in this study, five typical urban green species (Populus tomentosa, Salix matsudana, Pinus tabulaeformis, Platycladus orientalis, Poa Annua and arbor -shrub-grass green space) in three representative urban green spaces were monitored for the concentration of air anion, the air temperature and relative humidity, the concentration of carbon dioxide (CO2), and the noise level at different locations of green spaces in different seasons. Some conclusions can be seen from the results: (1) compared to the five single-specie arbor groves, arbor -shrub-grass green space has better eco-health function. Using the concentration of CO2 as an example, the highest concentration of air anion was found in a arbor -shrub-grass green space(435×10-6) ;(2) deciduous trees has better eco-health function in foliaceous period, while showed poor eco-health function in foliage-falling period. Using the concentration of air anion as an example, the highest number was found in deciduous tree groves(Salix matsudana) 1500 cm-3; (3) in terms of maintaining the eco-health function, evergreen conifer groves, represented by oriental arborvitae (Platycladus orientalis), showed a more steady result. The difference of the air anion concentrations is 154cm-3 ,which is half of the difference of deciduous specie(Poplus tomentosa)