Study Of Distribution Pattern Of Differentstanding Forest Negative Air Ions-Loess Plateau Hinterland Qiangyang County Ecology Environment Monitoring

In forest plants mainly growing season (April-October), using ITC-201A negative air ion monitor which is producted Japan Andes company to analyze and conclude negative air ion distribution rule and air quality index variation of six plantation and one desert on the loess plateau hinterland region in Qian-yang county.and do research on different stand negative air ion concentration changes relationship with temperature and relative humidity,in order to evaluate the air quality.The main research results are as follows:1.The positive and negative air ions concentration of different standing forests have great space time difference,the positive and negative changes in different months so as to form diauxie and unimodal curve.The main growing season (April-October) in different standing forests,the average positive and negative of different forests also have great difference.Each stand on negative air ions from high to low average density was as follows:shady slope Robinia pseudoacacia (887 ions/cm3)> tailo Robinia pseudoacaci (750 ions/cm3)> juvenile Populu s (747 ions/cm)> juvenile Robinia pseudoacacia (659 ions/cm)> juvenile Populus and Platycladus orientalis mingled forest (571 ions/cm3)> juvenile Platycladus orientalis (486 ions/cm3)> wasteland (457 ions/cm3).The average density of air positive ions from high to low as follows:juvenile Populus (1140 ions/cm3)> shady slope Robinia pseudoacacia (1120 ions/cm3)> juvenile Platycladus orientalis (870 ions/cm3)> juvenile Robinia pseudoacacia (690 ions/cm)> tailo Robinia pseudoacacia (660 ions/cm) > juvenile Populus and Platycladus orientalis mingled forest (560 ions/cm3)> wasteland (550 ions/cm3).2.Diurnal fluctuation tendency of forests NAIC have difference in different seasons,the stability of forests NAIC is the worst in Spring.The average size coeffrents of variation of forests NAIC is different juvenile Platycladus orientalis (0.281) is maximum, juvenile Robinia pseudoacacia (0.275) is second.juvenile Populus (0.187) is minimum.3.The change in concentrations of air negative ions concentration in the forest is air temperature increased while the air negative ions concentration decreased,and it increased with the increase of relative humidity. In the forest air negative ions concentration months changes, it increased with temperature and relative humidity rising.Temperature and relative humidity effection to the air positive concentration days and months changes were not significant.4.Each stand CI value had great spatio-temporal difference,CI value of month change were not the same,was roughly as double-peak and single-peak curve showing. The average of different forest CI value was also different,on average sequence for:juvenile Populus (0.64) > shady slope Robinia pseudoacacia (0.63)> tailo Robinia pseudoacacia (0.57)> juvenile Robinia pseudoacacia (0.48)> juvenile Populus and Platycladus orientalis mingled forest (0.44)> juvenile Platycladus orientalis (0.24)> wasteland (0.22).This means air quality of juvenile Populus is the best,shady slope Robinia pseudoacacia is second, wasteland is the worst.