Study On The Characteristics And Influence Factors Of The Climate And Air Quality In The Dagangshan Forest Region Of Jiangxi Province

Forest eco-tourism,forest bathing and forest health are the new industrial approaches to realize the whole forest utilization by transforming the production mode of state-owned forests and collective forests,to realize the transformation of department functions from wood production to ecological product production,and to realize the coordinated development of ecology and economy by transforming the development mode.Science and technology support is weak,the lack of basic data is a key bottleneck restricting the development of this new type of forest health industry.In this study,a typical representative of subtropical forest in dagang mountain of jiangxi province was taken as the research area.Relying on the dagang mountain national forest ecological station,the key parameters of the health function of typical forest stand in dagang mountain area were systematically analyzed using the national standard long-term field monitoring method.Through continuous observation,the characteristics of representative forest microclimate,the functions of scientific quantification of subtropical forest cooling and humidification,and the spatial and temporal distribution of air negative ions and air pollutants as well as their relationship with related influencing factors were clarified,and the forest health and nourishment effects brought by air negative ions and forest microclimate were preliminarily discussed.Single factor analysis of variance,correlation analysis and stepwise regression analysis were carried out with R language and other analysis tools.The following conclusions are drawn:(1)The function of Chinese fir forest in regulating microclimate is remarkable in dagang mountain.The total solar radiation intensity inside and outside the forest presented an inverted u-shaped curve with the diurnal change of air temperature.The total solar radiation outside the forest was significantly greater than that inside the fir forest,and the total solar radiation rate decreased by the fir forest was 87.9%to 91.5%.At night,the temperature outside the forest is lower than inside the forest,and the forest has the function of heat preservation.Chinese fir forest change temperature range 0.32?to 2.06?.The diurnal variation law of relative humidity of the air inside and outside the forest is contrary to the temperature.Chinese fir changes humidity range from 0.57%to 11.97%.Reunite 5 cm and 10 cm soil temperature daily variation overall showed a trend of sine and reunite soil temperature is greater than the forest,Chinese fir forest reduce 5 cm and 10 cm soil temperature 4.22?to 7.27?,3.69?to 7.36?.The soil moisture at 5cm and 10cm in the forest was lower than that in the forest,and the soil moisture at 5cm and 10cm in the fir forest decreased by 0.53-9.87%and 3.74-10.32%,respectively.The seasonal variation law of wind speed outside the forest presents inverted u-shaped curve on the whole,and there is no obvious law of wind speed inside the forest.Chinese fir reduced wind speed by 0.39m/s to 0.51m/s.The diurnal variation of wind direction outside the forest was larger than that inside the forest.According to the correlation,the total solar radiation in and out of the four seasons forest is significantly positively correlated with air temperature,and inversely correlated with air relative humidity.The correlations of other meteorological elements were different in spring,summer,autumn and winter,in and out of forests.(2)The distribution law of air negative ions in dagangshan forest region is as follows:First,the distribution of time.Diurnal variation characteristics:The diurnal variation of anion concentration in spring and summer is multi-peak curve,and"M"type curve in autumn.Monthly changes:August>July>may>June>April>march>October>November>September>January>February>December.Seasonal change rule:in seasonal change,the change rule of air negative ion concentration was ranked from large to small:summer,spring,autumn,winter.Second,the negative ion law of different interference types:The diurnal variation of anion concentration in evergreen broad-leaved forest presented a fluctuation curve as a whole,cedar forest and bamboo forest showed a"U"pattern of fluctuation,rice field showed an inverted"U"pattern of fluctuation,river curve was poor,residential area showed an"M"pattern of curve,and main road showed a negative multi-peak curve of fluctuation.Under different interference modes,the daily mean value of anion concentration was ranked from large to small:cedar forest,bamboo forest,river,evergreen broad-leaved forest,paddy field,residential area and main road.Air anion concentration is positively correlated with total solar radiation,air temperature,5cm soil temperature and wind speed in four seasons,and negatively correlated with air relative humidity and wind direction,and is different from other meteorological factors in four seasons.In spring,summer and autumn,the concentration of air negative ions is significantly correlated with NO₂,SO₂,O₃ and PM_2.5.The correlation between CO and PM₁₀ is significantly different in the four seasons.In winter,the correlation is significantly different in the other three seasons.(3)The temporal distribution of atmospheric pollutants:The daily variation law of NO₂ concentration in the four seasons presents an inverted"U"curve,SO₂ is a"U"curve,CO concentration in winter presents an inverted"V"curve,and other three seasons show gentle fluctuation curve,while the concentration of O₃ and PM₁₀ vary greatly in the four seasons.In winter,PM_2.5 concentration presents an inverted"V"curve,while in the other three seasons,it presents an inverted"U"curve.The order of pollutant concentration is SO₂>CO>O₃>NO₂>PM₁₀>PM_2.5 in spring and summer,SO₂>CO>PM₁₀>O₃>NO₂>PM_2.5 in autumn,and CO>SO₂>PM₁₀>NO₂>O₃>PM_2.5 in winter.The order of air pollutants is spring,summer,autumn and winter.NO₂,SO₂,O₃ and PM_2.5 are significantly correlated with each other in the four seasons,and the correlation with CO and PM₁₀ is different in the four seasons.The concentration of NO₂,O₃ and PM_2.5 has the same positive and negative correlation with meteorological factors,while the concentration of SO₂ and CO has the same positive and negative correlation with meteorological factors.The concentrations of SO₂,CO,NO₂,O₃ and PM_2.5 have completely opposite positive and negative correlations with meteorological elements.(4)The comfort level of body sensation in dagang mountain forest area is"extremely uncomfortable"except for the inside and outside of the forest in winter,and reaches above"comfortable"level in other seasons.Anion level is in"air is pure and fresh general,to health normal"above.The concentrations of NO₂,SO₂,CO,O₃,PM₁₀ and PM_2.5 in four seasons are all within the highest standards for pollutant project concentration.It is recommended that people have fun and rest in summer morning and afternoon,spring noon and afternoon,autumn noon and afternoon.The crowd that enjoys negative ion bath can be in spring,summer.Health base,nursing home site can be close to cedar forest,bamboo forest,river,evergreen broad-leaved forest,open time in summer,spring,autumn is the best.