基于单木模型对温州常见城市绿化树种固碳增湿能力的比较

摘要

The study of the carbon fixation and humidification capacity is the fundamental research of ecological benefits of urban green space.However,exsiting research was mainly focused on the per unit leaf area scale,which had a large limitation in practical application.The carbon fixation and humidification capacity of the main greening tree species in Wenzhou city was compared,and the carbon fixation model of individual tree was constructed.Results calculated by the carbon fixation model of individual tree showed that the order of daily carbon fixing and oxygen releasing capabilities of arbor (diameter at breast height of 20 cm) from high to low was as follows:Ficus concinna,Eucalyptus robusta,Cinnamomum camphora,Liriodendron chinense,Michelia alba and Osmanthus fragrans.The values were 3 376.538,1 603.181,416.308,368.626,252.232 and 39.444 g,respectively.And the order of humidification capabilities from high to low was as follows:Ficus concinna,Eucalyptus robusta,Liriodendron chinense,Cinnamomum camphora,Michelia alba and Osmanthusfragrans.The values were 859.960、259.532、118.930、97.646、69.308 and 33.344 g,respectively.These orders of the carbon fixation,oxygen release and transpiration amounts calculated by the per unit leaf area were different from the order that calculated by the carbon fixation model of individual tree.The reason was that the total leaf area was ignored in the traditonal method.Thus,the carbon fixation model of individual plant was more accurate to estimate the carbon fixation and humidity increasing capacity.%在比较单位叶面积固碳增湿能力的基础上,结合树种叶面积,研建了单木固碳模型并对其固碳增湿能力进行了比较.结果表明,以乔木树种(胸径为20 cm)为例,其日固碳放氧能力由大到小依次为小叶榕Ficus concinna、桉Eucalyptus robusta、樟Cinnamomum camphora、鹅掌楸Liriodendron chinense、白兰Michelia alba和木犀Osmanthus fragrans,其值分别为3 376.538、1 603.181、416.308、368.626、252.232和39.444g;其降温增湿能力由大到小依次为小叶榕、桉、鹅掌楸、樟、白兰和木犀;日蒸腾耗水量分别为859.960、259.532、118.930、97.646、69.308和33.344 g.该顺序与单位叶面积固碳放氧和降温增湿能力的顺序有所不同.分析认为,这是由于基于单位叶面积尺度上固碳能力的比较没有考虑到不同树种的树冠大小等因素,而考虑其叶面积所构建的单木固碳模型则更加准确且具实用性.