不同径阶青杄林和油松林滞尘能力研究

Dust-retaining Ability of Picea wilsonii and Pinus tabuliformis Forests with Different Diameter Classes

通过常规洗涤法和超声波洗涤法研究不同径阶青杄和油松滞尘能力的差异,为科学地选择造林树种和定向培育森林提供理论依据。研究同一林分中不同径阶的林木对大气中PM_(2.5)、PM_(10)及TSP在单位叶面积上的滞尘量,并进行叶表形态特征观察。结果表明,无论在同一树种不同径阶还是相同径阶不同树种条件下,青杄和油松径阶在20~24 cm时PM_(2.5)、PM_(10)及TSP单位叶面积滞留颗粒物量达到最大;同一条件下,青杄的单位叶面积PM_(2.5)、PM_(10)及TSP滞尘量要大于油松;青杄的叶表面有不规则的凸起和凹陷结构,还分布有少量气孔;油松正反叶表面存在较深、较规则的条状凹槽,附着有分泌物,且反面气孔多于正面;超声清洗法所得的单位叶面积PM_(2.5)、PM_(10)及TSP滞尘量是常规洗涤法所得滞尘量的3倍,两者差异显著。青杄和油松对大气颗粒物吸附效果最好的是(20~24 cm)径阶组,且同一条件下,青杄对大气颗粒物的吸附能力要强于油松;植物叶表面结构越不规则、越粗糙,则滞尘能力越强,同时叶表分泌物和叶片吸滞面积对滞尘能力也有影响;对叶片表面颗粒物的洗涤,超声波清洗法要优于常规洗涤法。随着径阶的增长,单株青杄叶生物量基本呈逐渐增大的趋势。单株油松叶生物量在径阶16~28 cm随径阶的增加有上升的趋势。

To study the differences in the dust-retaining ability of Picea wilsonii and Pinus tabuliformis forests with different diameter classes to provide a theoretical basis for scientific selection of afforestation tree species and oriented cultivation.The conventional washing method and ultrasonic washing method were used to study the dust retention of particulate matters(PM2.5,PM10 and TSP)in the atmosphere per unit leaf area,and scanning electron microscopic method was adopted to observe the morphological characteristics of the leaf surface.For both tree species,he amount of retained particles reached the maximum on the leaf surface of the trees with diameter of 20-24 cm.Under the same conditions,the amount of dust retention of P.wilsonii was higher than that of P.tabuliformis.Microscopic observation indicated that the leaf surface of P.wilsonii distributed irregular convex and concave structures,and a small amount of pores;while for P.tabuliformis,deep,relatively regular strip-shaped grooves with attached secretions were observed,and the number of the pores on the adaxial side was more than on the abaxial side.The amount of dust retention washed by ultrasonic cleaning method tripled the conventional washing method,the difference between the two method was significant.The best diameter range for P.wilsonii and P.tabuliformis to retain dust was 20-24 cm.The adsorption capacity of P.wilsonii was stronger than P.tabuliformis.The more irregular and coarser surface structure of plant leaves,the stronger the dust retention ability.The leaf surface secretion and leaf stagnation area also made contribution for the dust retention ability.The ultrasonic cleaning method was superior to the conventional washing method for the washing of the surface particles.With the increase of the diameter class,the biomass of the leaves of P.wilsonii showed a gradually increasing trend.The leaf biomass of a single plant of P.tabuliformis showed an upward trend with the increase of the diameter step between 16 cm and 28 cm.