不同模式防护林内PM_(2.5)浓度变化及其影响因子分析  

Variation of PM_(2.5) concentration and its influencing factors in protective forests under different patterns

作　　者：李立文 周润洋 万欣[1,2] 邢玮 LI Li-wen;ZHOU Run-yang;WAN Xin;XING Wei(Jiangsu Academy of Forestry Sciences,Nanjing,Jiangsu 211153,China;Jiangsu Yangzhou Urban Forest Ecosystem National Observation and Research Station,Yangzhou,Jiangsu 225000,China;College of Horticulture and Landscape Architecture,Yangzhou University,Yangzhou,Jiangsu 225009,China)

机构地区：[1]江苏省林业科学研究院,江苏南京211153 [2]江苏扬州城市森林生态系统国家定位观测研究站,江苏扬州225000 [3]扬州大学园艺园林学院,江苏扬州225009

出　　处：《南方农业学报》2024年第9期2689-2700,共12页Journal of Southern Agriculture

基　　金：江苏省林业科技创新与推广项目(LYKJ[2021]38)。

摘　　要：【目的】探究不同模式防护林内直径≤2.5μm的是浮颗粒物(PM_(2.5))浓度变化及其影响因子,为优化防护林植物配置,建设宜居城市环境提供理论参考依据。【方法】以6种植物配置模式(榉树+桃树混交林、落羽杉纯林、落羽杉+石楠混交林、女贞+落羽杉混交林、女贞纯林和榉树+樱花混交林)且林龄均在10年左右的防护林为研究对象,空旷地作为对照(CK),测定防护林和CK的空气温度、空气湿度、气压、风向、PM_(2.5)浓度、光照强度6种环境因子及9种土壤理化因子,并分析不同防护林模式下气候和土壤因子之间相关性;通过建立随机森林模型分析不同种植模式的重要性得分。【结果】落羽杉纯林、落羽杉+石楠混交林、女贞+落羽杉混交林模式下PM_(2.5)浓度低于榉树+桃树混交林、女贞纯林和榉树+樱花混交林3种防护林模式和CK。7个监测点的土壤pH均呈弱碱性,女贞+落羽杉混交林和女贞纯林模式的有机质含量显著高于其他防护林模式和CK(P<0.05),落羽杉纯林模式下有效磷含量为最高值,为14.53 mg/kg。相关分析结果表明,PM_(2.5)浓度与空气湿度、土壤微生物碳和土壤微生物氮含量之间呈极显著正相关(P<0.01,下同),与空气温度呈极显著负相关,铵态氮与PM_(2.5)浓度相关性不显著(P>0.05)。随机森林模型结果显示,空气温度、空气湿度、气压、风向、光照强度、土壤微生物碳、土壤微生物氮和含水量对PM_(2.5)浓度影响的重要性得分较高。【结论】不同防护林模式下的风向和PM_(2.5)浓度有差异,空气温度、空气湿度、土壤微生物碳和土壤微生物氮含量是影响大气PM_(2.5)浓度变化的重要因子,防护林配置落羽杉能有效降低大气PM_(2.5)浓度。【Objective】To explore the variations in(PM_(2.5))concentrations in different protective forest patterns and their influencing factors,which could provide theoretical basis for optimizing plant arrangements in protective forests and for the development of livable urban environments.【Method】This study focused on 6 plant configuration patterns within protective forests,including mixed forests of Zelkova serrata and Prunus persica,pure stands of Taxodium distichum,mixed forests of Taxodium distichum and Photinia serratifolia,mixed forests of Ligustrum lucidum and Taxodium distichum,pure stands of Ligustrum lucidum,and mixed forests of Zelkova serrata and Prunus serrulata,all with an approximate stand age of 10 years.An open space served as the control(CK).The 6 environmental factors(air temperature,air humidity,atmospheric pressure,wind direction,PM_(2.5) concentration and light intensity)and 9 soil physicochemical pro-perties were measured in both the protective forests and the control site.Correlations between climatic and soil factors across different protective forest patterns were analyzed.A random forest model was employed to assess the importance scores of different planting patterns.【Result】PM_(2.5) concentrations under pure stands of Taxodium distichum,mixed forests of Taxodium distichum and Photinia serratifolia and mixed forests of Ligustrum lucidum and Taxodium distichum were lower than those in mixed forests of Zelkova serrata and Prunus persica,pure stands of Ligustrum lucidum,mixed forests of Zelkova serrata and Prunus serrulata,as well as the CK site.Soil pH at all 7 monitoring points was slightly alkaline.Organic matter content in mixed forests of Ligustrum lucidum and Taxodium distichum and pure stands of Ligustrum lucidum was significantly higher than in other protective forest patterns and the CK(P<0.05).The highest available phosphorus content(14.53 mg/kg)was found in pure stands of Taxodium distichum.Correlation analysis indicated that PM_(2.5) concentration was extremely significant

关 键 词：防护林 环境因子 PM_(2.5) 土壤微生物碳 土壤微生物氮 

分 类 号：S727.2[农业科学—林木遗传育种]