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.