城乡特色核桃防护林树种配置结构对空气颗粒物及温湿度的影响

【目的】分析干旱区城乡核桃林与不同树种配置结构空气颗粒物浓度变化差异，探讨树种配置结构与大气颗粒物浓度、温度、相对湿度间的关系，为区域环境绿化建设提供理论参考。【方法】以新疆叶城县城区、城郊和乡村3个不同区域树种配置结构的林带为监测点，树种配置分别是苹果（Malus domestica）—核桃（Juglans regia）、红枣（Ziziphus jujuba Mill.）、红枣—核桃、新疆杨（Populus alba）—核桃和核桃，通过监测防护林内和林带不同水平距离颗粒物浓度、空气温度和相对湿度，分析大气颗粒物的时空变化规律、防护林不同水平距离对颗粒物浓度的削减作用。【结果】颗粒物浓度具有明显的时空差异。城区、城郊和乡村核桃防护林颗粒物浓度污染排序依次为乡村>；城郊>；城区；城区、城郊和乡村核桃防护林的PM_2.5最高浓度分别出现在20: 00（20.00 μg/m3）、12:00（29.00 μg/m3）和14: 00（58.25 μg/m3）；PM₁₀最高浓度分别出现在20: 00（35.25 μg/m3）、14: 00（62.67 μg/m3）、14: 00（131.50 μg/m3）；PM_1.0最高浓度分别出现在20:00（12.50 μg/m3）、12: 00（12.67 μg/m3）、14: 00（28.75 μg/m3）。树种不同配置结构颗粒物浓度存在差异，排序依次为核桃>；对照>；新疆杨—核桃>；红枣>；苹果—核桃>；红枣—核桃。防护林不同水平距离对PM_2.5浓度消减程度不同。城区与城郊不同水平距离削减作用排序为0 m>；20 m>；10 m；乡村依次为0 m>；10 m>；20 m。城区与城郊核桃防护林温度差异不明显，二者的温度明显高于乡村防护林温度；城区、城郊和乡村核桃防护林相对湿度均存在波动变化。PM_2.5浓度与温度呈极显著负相关（P<0.01，下同），与相对湿度呈显著正相关（P<0.05），PM_1.0浓度与温度、相对湿度的相关性均达极显著水平，PM₁₀与温度、相对湿度相关性均不显著（P>0.05）。【结论】核桃林在城区、城郊和乡村发挥的生态效益存在一定差异，在乡村能明显改善空气质量；核桃林带搭配种植红枣可充分发挥其生态效益，在农业环境污染较重的地区可作防护林带选用。

Influence of special Juglans regia shelterbelts species configuration structure on air particulate matter,temperature and humidity in urban and rural areas

【Objective】To quantitatively analyze the differences in air particulate matter concentration changes between different regional Juglans regia forests and different tree species configuration structures in arid zones, to explore the relationship between different tree species configuration structures and atmospheric particulate matter concentration, temperature and relative humidity, and to provide theoretical references for regional environmental greening construction.【Method】Take the forest belts with fruit tree configurations in urban, suburban and rural areas of different areas of Yecheng, Xinjiang as the monitoring points. They were Malus domestica-J. regia, Ziziphus jujuba Mill., Z. jujuba Mill.-J. regia, Populus alba-J. regia, J. regia. By monitoring the concentration of particulate matter, air temperature and relative humidity within the shelterbelts and at different horizontal distances from the forest belts, the spatial and temporal variation patterns of atmospheric particulate matter and the reduction effect of different horizontal distances from the shelterbelts on the concentration of particulate matter were analyzed.【Result】Particulate matter concentrations had obvious spatial and temporal differences. The highest concentrations of PM_2.5 in urban, suburban and rural walnut shelterbelts occurred at 20:00(20.00 μg/m3), 12:00(29.00 μg/m3) and 14:00(58.25 μg/m3), respectively;the highest concentrations of PM₁₀ occurred at 20:00 (35.25 μg/m3), 14:00 (62.67 μg/m3), and 14:00 (131.50 μg/m3) respectively;the highest PM_1.0 concentrations occurred at 20:00(12.50 μg/m3), 12:00(12.67 μg/m3), and 14:00(28.75 μg/m3), respectively. The decreasing order of particle concentration in different planting types was as follows:J. regia L.>control>P. alba-J. regia L.> Z. jujuba Mill.>M. domestica-J. regia L.>Z. jujuba Mill.-J. regia L. Different levels of protection forests had different levels of reduction of PM_2.5 concentration. The reduction degree of shelterbelts at different distance to PM_2.5 concentration was different.The size of the reduction effect at different horizontal distances in urban and suburban areas was:0 m>20 m> 10 m;0 m>10 m>20 m in rural areas in order. The temperature difference between urban and suburban J. regia shelterbelts was not obvious, the relative humidity trend was large, temperatures of urban and suburban J. regia shelterbelts were higher than that in rural areas;and the relative humidity difference among urban, suburban and rural J. regia protection forests had fluctuation change;and the PM_2.5 concentration had extremely significant negative correlation with temperature(P<0.01, the same below) and had significant positive correlation with relative humidity(P<0.05), the correlation between PM_1.0 concentration and temperature and relative humidity were both extremely significant, and the correlation between PM₁₀ and temperature and relative humidity were not significant (P>0.05).【Conclusion】The ecological benefits of J. regia forest in urban, suburban and rural areas are somewhat different, and it can greatly improve the air quality in rural areas;the J. regia forest belt can give full play to its ecological benefits with the planting of Z. jujuba, and it can be used as a protective forest belt in areas with heavy agricultural environmental pollution.