| Urban forest has become an important place for people to have leisure and recreation due to its ecological and health functions.Therefore,its environmental factors such as air quality and microclimate comfort degree have been widely concerned and forest health tourism has become an important component of forestry industry in China.Therefore,it is of great practical significance to conduct a comprehensive study on the dynamic changes of the health care factors in the forest environment.In this paper,three typical forest under differnt habitats in Yuanshan Park of Shenzhen were chosen as reserch objects.During the whole day from the summer of 2015 to the autumn of 2016,we monitored several environmental factors such as microclimate factors,the concentration of air particles,ozone concentration and negative ion concentration.Then,their temporal~spatial changes were analyzed.At the same time,the environmental factors of downtown square were also monitored as control.Finally,the effect of forest environment was evaluated by animal outdoor simulation test.The results showed that:1.Compared with the downtown square,three forests can all significantly improve the human comfort degree.The lowest temperature,strongest wind speed,illumination and UVB radiation were all appeared at ridge,but the maximum relative humidity in the river valley.There are several significant seasonal variations of the microclimate indicators of the three forests in a year.According to the diurnal variation,thehighest temperature,illumination and UVB radiation intensity reached in 13:00~15:00,but the trend of relative humidity was opposite to that of air temperature in each forest.The microclimate of each forest is very comfortable in spring and autumn,and of ridge forest for comfort in summer.2.The annual concentration of coarse(>2.5 m)and fine(≤ 2.5 m)particles in the three forests were all reduced than in the square.The particle mass concentration of different size was higher in spring and autumn than in summer,and the highest mass concentration was in the foothill forest,but the lowest was in the ridge forest in spring and autumn.During summer,the four kinds of particles were all lowest in ridge forest,and the coarse particle was highest in foothill forest,and the fine particle was highest in river valley forest.The best cleanliness of air particle was in summer.In addition,the concentrations of four kinds of particle matters with the peaks usually appeared at 1:00~7:00,and the vales at 11:00~17:00 during the observation period in autumn and summer,however the peak at 11:00~13:00,the vales at 1:00~3:00,15:00~17:00 in autumn.3.Daily average and 8 h maximum average ozone concentration were all the highest in the ridge forest throughout the year,and its in summer was higher than in spring and autumn,but they have all reached the primary standard of national air quality standards(160 and 100 μg/cm3,respectively).The daily variation of ozone concentration in 3 forests all exhibited a single peak curve,with the highest concentration occurring in 13:00~19:00 pm,whereas the lowest occurring in 1:00~7:00 am,and the hourly mass concentration all achieved the national grade~I level.4.The concentration of negative air ions in the whole year and every season was 15 times higher than that in the square.Among the three forests,the highest concentration was occured in the river valley forest during spring,but in summer it was in the ridge forest,and there was few difference among the three forests in autumn.The seasonal variation in the concentration of negative air ions was shown as summer > spring > autumn.The peak of air negative anion concentration was observated in 3:00~9:00,while the valley was around 13:00.5.The animal experiment showed that,the total movement distance,the central grid movement index included movement distance,dwell time and entry times,the standing frequency of the experimental mice in the three kind of forests were all higher than the mice living indoors.The experiment results showed that the three forest environments were useful to enhance learning,memory,exploration and cognitive abilities of mice,and improve their mental state.Comparatively analyzing the environmental factors in both experimental conditions,the finding showed that,the environmental condition in three forests were all significantly better than indoors condition,and these forests were suitable for human health care.Through comparative analysis and evaluation on the annual,seasonal,daily changes of environmental factors inside three forests,combining with the animal experiments,this program will provide a theoretical basis for the development and construction of forest health care environment in Yuanshan Park of shenzhen. |
