成都青羊区背街小巷行道树孢粉致敏风险分析

为研究背街小巷行道树的孢粉致敏风险,以成都市青羊区410条背街小巷为例,在记录背街小巷行道树特征的基础上,计算其孢粉致敏风险指数(I_UGZA)并叠加区域人口密度图,获得青羊区背街小巷的孢粉致敏风险地图。结果表明: 410条背街小巷共有行道树32461棵,属27科、41属、52种。树种分布严重不均,过度使用小叶榕(占比31.8%)、银杏(12.9%)和香樟(8.5%)。背街小巷的I_UGZA均值为2.61,致敏风险较高,春季为首要风险季。其中,175条背街小巷的致敏程度低(I_UGZA为0～1),174条致敏程度相对较低(I_UGZA为1～5),6条致敏风险极高(I_UGZA为15～20)。相关性分析显示,背街小巷平均树高和树冠与街道面积比是影响其I_UGZA的关键因素。叠加人口密度图后显示,青羊区行道树孢粉致敏风险较高的街区主要是少城街道、草市街道、西御河街道、府南街道和苏坡街道片区。

Allergenic risk analysis of street trees of urban alleys in Qingyang District,Chengdu, China

We examined the pollen allergy risk of street trees in urban alleys, with 410 urban alleys in Qingyang District, Chengdu as an example. On the basis of recording the characteristics of street trees, we calculated the index of allergenicity of urban green zones (I_UGZA) values and overlay the regional population density map, and finally obtained the pollen allergy risk map of urban alleys in Qingyang District. The results showed that there were 32461 street trees in 410 urban alleys, belonging to 27 families, 41 genera, and 52 species. The distribution of tree species was extremely uneven, with excessive plantation of Ficus concinna (31.8%), Ginkgo biloba (12.9%) and Cinnamomum camphora (8.5%). The risk of pollen allergy in urban alleys was high, with an average I_UGZA value of 2.61 and spring as the primary risk season. Among them, 175 alleys were at the most low allergy degree (I_UGZA=0-1), 174 alleys at low degree of allergy (I_UGZA=1-5), and 6 alleys at extremely high risk of allergy (I_UGZA=15-20). Results of correlation analysis showed that mean tree height and canopy-to-street area ratio were the key factors affecting I_UGZA of street trees in urban alleys. After superimposing the population density map, Shaocheng Street, Caoshi Street, Xiyuhe Street, Funan Street, and Supo Street had a high risk of pollen allergy.