保定5种主要绿化树种叶片滞尘对气体交换特征的影响

Effect of the Airborne Dust Detainment on Gas Exchange with in Five Major Landscape Plants in Baoding

研究了保定市五种主要绿化树种在滞尘状态下不同立地条件的气体交换特征变化,在此基础上,对植物叶片滞尘量与气体交换参数损失率的关系进行了相关性分析。结果表明:(1)榆叶梅和金银木的净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)在同一立地与其他树种相比损失率较大,悬铃木和臭椿相对较小,即本文中的臭椿、悬铃木对颗粒物污染生境的适应能力较强,大叶黄杨居中,金银木、榆叶梅较差;(2)五种阔叶树种悬铃木、臭椿、金银木、榆叶梅、大叶黄杨的滞尘与洁净叶片气体交换参数损失率(ΔPn、ΔGs、ΔTr)均呈现道路旁>街头绿地>校园的规律且道路旁的变化值与校园呈显著差异(P<0.05);(3)植物叶片的气体交换参数损失率随叶片滞尘量的增加而增大呈明显的正相关关系。

Gas exchange of the five major landscape plants detaining dust at different sits were studied and dust detaining capacity in correlation with the loss rate of gas exchange parameter were analyzed.The results showed that:(1)The loss rate of net photosynthetic rate(Pn),transpiration rate(Tr),stomatal conductance(Gs) of Lonicera maackii and Prunus triloa were higher than the other tree species under the same site conditions,indicating smaller loss rate of gas exchange parameters but higher adaptability to airborne dust environment for Platanus acerifolia,Ailanthus altissima;(2) The loss rate of gas exchange parameters with dust born leaves and clean leaves for the five broad leaved tree species —P.acerifolia,A.altissima,L.maackii,P.triloba and Buxus megistophylla on the basis of site conditions,followed the trend :road side>street greenbelt>campus,with remarkable differences between road side and campus(P<0.05);(3)Correlation analysis showed an remarkable positive correlation between loss rate of gas exchange parameters and amount of dust detained.