Research Progress on Forest Negative Air Ions in China
Negative air ion has the important function of cleaning air and maintaining health care,and is an important indicator for monitoring air quality.The forest provides a favourable environment for the production of negative air ion.According to the relevant research literature,the production mechanism of negative air ion in forest,the change pattern and influencing factors of its concentration and the grading evaluation cri-teria were discussed.There were obvious diurnal and seasonal variation characteristics for negative air ion in forest.The concentration of nega-tive air ion in forest was generally high in the morning and evening,but low at noon in a day,and higher in summer and autumn than in winter and spring.The general trend of negative air ion concentration decreased with the increase of latitude,and within a large vertical gradient of al-titude it rose first and then decreased.Temperature,humidity,stand types,human activities and other factors also had different effects on the negative air ion concentration in forest.
ForestNegative air ionSpatial and temporal distributionInfluencing factors
万方数据
维普
