热带山地雨林CO_2浓度环境的时空梯度特征  

Space-time character of CO_2 content in tropical mountain rain forest of Jianfengling, Hainan

作　　者：陈步峰[1] 李意德[1] 林明献[1] 邱坚锐[1] 骆土寿[1] 周铁烽[1] 

机构地区：[1]中国林科院热带林业研究所,广州510520

出　　处：《生态学报》2001年第12期2089-2095,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 ( No.39870 6 1 8)研究内容

摘　　要：基于 2 0 0 0年旱、雨季梯度观测结果叠加分析 :晴及晴间少云天气 ,山地雨林垂直 CO2 浓度雨季在 333～ 35 0 ml/ m3的时间空间特征显著即 8:0 0～ 1 8:0 0林内 1 6 m至冠顶 2 8m,较旱季浓度分别小 1 0～ 2 1、7～ 2 0 .2 ml/ m3 ,夜间呼吸影响空间的最大浓度均在近林地上 5 m、出现时段有季节性差别。 8:0 0～ 1 8:0 0林冠上 CO2 浓度梯度、气温梯度表明 ,大气至林冠的 CO2 通量和冠层指向大气的热通量特征显著 ,夜间则梯度值减小、方向相反 ,且雨季晴天的 ΔCt/ ΔZ大于旱季 ,旱季气温梯度大于雨季 ;林内二氧化碳垂直梯度 ( ΔCt/ ΔZ<0 )昼夜均小于零 ,即林地指向上层的 CO2 通量特征显著 ,且两类天气均表现出雨季的浓度梯度大于相应的旱季。从而 ,科学地揭示出在 2 8m的山地雨林垂直高度上 ,植物光合固定 CO2最多而导致空间浓度最低的季节、天气、时间和空间 ,同时证实冠上两个高度实时气温与相应 CO2 浓度成 CCO2 =a1 0 b/ T。而山地雨林水汽压时空则较为直观地解释了蒸发、扩散和乱流机制影响的效果以及雨林“雨”The content of carbon dioxide ranges from 333ml/m\+3 to 350ml/m\+3 in rainy season appeared in the time range from 8:00 to 18:00 and height range from 16 m to the canopy top in a tropical mountain rain forest. The CO 2 content range in rainy season was 7~22ml/m\+3 less than that in the dry season. At night the maximum content of carbon dioxide was 5m above the forestland and appeared different time in both weathers.Diurnal (8:00 ~18:00) vertical grade (ΔC t/ΔZ) of carbon dioxide above the canopy showed that it there was a marked flux character of carbon dioxide and the flux aspect was from atmosphere to the canopy. Nightly the grade value was decreased and became opposite aspect. Likewise, ΔC t/ΔZ value of the fine in the rainy season was more than that in the dry season and ΔT t/ΔZ in dray season was more than that of the rainy season. Because of daily ΔC It/ΔZ inner forest was negative, so flux was upward from the forestland of tropical mountain rain forest, and ΔC It/ΔZ value of rainy season was more than that of dry season corresponding in the both weathers. It was found that the space-time of optimal photosynthesis and purgative function in the tropical mountain rain forest was by height of 28 m. At the same time, there was a correlation between temperature and CO 2 content above the canopy that model was C CO 2=a10 b/T. The mechanism of water vapor's exchanging and morning rain inner forest was explained by daily space-time character of the water vapor pressure.

关 键 词：热带山地雨林 CO2浓度 微气象梯度 时空特征 

分 类 号：S718.5[农业科学—林学]