Research On Soil Respiration And Its Environmental Factors Of Typical Bamboo Forest In Northwest Zhejiang

In Northwest Zhejiang, the soil respiration rate in the phyllostachys edulis forest and the phyllostachys praecox forest under intensive management and extensive management were measured by Li-Cor 8150 open soil carbon flux measurement system from January to December in 2013. This paper analyzed daily, monthly dynamic of the main environmental factors which influenced the soil respiration in the phyllostachys edulis forest, and also in the phyllostachys praecox forest under intensive management and extensive management, discussed the characteristics of daily, monthly and seasonal dynamic of the soil respiration, at the same time researched the relationship among the soil respiration and the main environmental factors, estimated soil carbon release in the phyllostachys edulis forest, and also in the phyllostachys praecox forest under intensive management and extensive management, to provide scientific basis for bamboo forest ecosystem carbon recycle in subtropical regions of our country. The results showed that:1.The daily dynamic of soil respiration in the phyllostachys edulis forest, and in the phyllostachys praecox forest under intensive management and extensive management all presented a single peak curve, but the extreme value of daily dynamic appeared at different times. The highest value of daily dynamic in the phyllostachys edulis forest appeared between 14:00 and 18:00, the lowest value appeared at 0:00 or 6:00. The maximum value of daily dynamic in the phyllostachys praecox forest under intensive management appeared at 12:00~16:00, the minimum occurred in 4:00~6:00. The maximum value of daily dynamic in the phyllostachys praecox forest under extensive management appeared at 14:00~16:00, the minimum occurred in 4:00~6:00. It is showed that soil respiration rate of the phyllostachys edulis forest and phyllostachys praecox forest with intensive management and extensive management in the day were all higher than in the night.2.The monthly dynamic of soil respiration rate in the phyllostachys edulis forest showed a single peak curve, the maximum value of soil respiration rate appeared in August, the minimum value in January. The monthly dynamic of soil respiration rate of the phyllostachys praecox forest with intensive management presented a double peak curve, the peak value of soil respiration rate appeared in February and August, the valley value in December. The monthly dynamic of soil respiration rate of the phyllostachys praecox forest with extensive management showed a single peak curve, the peak value of soil respiration rate appeared in August, the valley value in December. The annual average values of soil respiration rate in the phyllostachys edulis, in the phyllostachys praecox forest under intensive management and extensive management were 3.11μmol·m-2·s-1, 5.08μmol·m-2·s-1and 3.01μmol·m-2·s-1.3.The seasonal dynamic of the soil respiration rate in phyllostachys edulis forest expressed as: summer > autumn > spring > winter. The seasonal dynamic of the soil respiration rate of phyllostachys praecox forest with intensive management expressed as: summer > winter > spring > autumn. The seasonal dynamic of the soil respiration rate of phyllostachys praecox forest with extensive management expressed as: summer > spring > autumn> winter. There were seasonal differences of soil respiration rate in the phyllostachys edulis forest, The average value of soil respiration rate in summer and winter was significantly(P<0.01), There were not significant differences in spring and autumn(P>0.05). There were obvious differences of soil respiration rate among four seasons in the phyllostachys praecox forest(P<0.01)under intensive management and extensive management.4.The soil respiration rate in the phyllostachys edulis forest, in the intensive management phyllostachys praecox forest, in the extensive management, and in the intensive management phyllostachys praecox forest with the effect of covering date in January and February eliminated had high considerably exponential correlations with atmospheric temperature and soil temperature in 5cm depth(p<0.01). The soil respiration rate in the phyllostachys edulis forest, in the intensive management and extensive management phyllostachys praecox forest were not related with atmospheric humidity(P>0.05). Soil respiration rate in the phyllostachys edulis forest was not significantly correlated with soil water content in 5cm depth and atmospheric humidity(p>0.05). There were highy siginificant exponential correlation between soil respiration rate and soil water content in 5cm depth of the phyllostachys edulis forest(P<0.01). There was no relationship between soil respiration rate and soil water content in 5cm depth in the extensive management phyllostachys praecox forest, in the intensive management phyllostachys praecox forest with the effect of covering date in January and February eliminated(p>0.05).5.Q10 value(temperature sensibility index)of soil respiration in the phyllostachys edulis forest, in the intensive management phyllostachys praecox forest, in the extensive management, and in the intensive management phyllostachys praecox forest with the effect of covering date in January and February eliminated, were 2.80, 1.63, 2.51 and 1.82.6.The monthly variation of soil carbon release in the phyllostachys edulis forest, and in the phyllostachys praecox forest under intensive management and extensive was all obvious. The maximum value of soil carbon release in the phyllostachys edulis forest appeared in August(2.14 t C·hm-2), The monthly variation of soil carbon release in the intensive management phyllostachys praecox forest presented two peaks, which appeared in February(2.38 t C·hm-2·a-1)and August(2.48 t C·hm-2·a-1). The soil carbon release in the extensive management phyllostachys praecox forest has a peak which appeared in August(1.96 t C·hm-2·a-1). The annual soil carbon release in the phyllostachys edulis forest, in the intensive management Phyllostachys praecox forest,and in the extensive management Phyllostachys praecox forest in 2013,were 11.83, 19.16 and 11.44 t C·hm-2·a-1.