Spatial and temporal variation in soil respiration in a seasonally dry tropical forest, Thailand
Spatial and temporal variation in soil respiration in a seasonally dry tropical forest, Thailand
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DOI：
10.1017/s026646740999006x
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发表时间：
2009-09-01
影响因子：
1.4
通讯作者：
Koizumi, Hiroshi
中科院分区：
文献类型：
--
作者：
Adachi, Minaco;Ishida, Atsushi;Koizumi, Hiroshi
在泰国的热带干旱森林土壤呼吸速率的空间和季节变化进行了调查。在50个点内的2公顷的地块在森林地面在旱季和雨季的空间变化进行了研究。分别在16个点和5个点测定了土壤呼吸的季节变化和日变化。雨季的平均土壤呼吸速率为1041 +/- 542 mg CO2 m（-2）h（-1）（平均值+/- SD），约为旱季的两倍。丰水期土壤呼吸速率与土壤含水量呈负相关。土壤呼吸与土壤含水量的关系可用一个多项式方程来描述：土壤呼吸速率随土壤含水量的增加而增加，但当土壤含水量超过21%时，土壤呼吸速率开始下降。土壤呼吸速率的日变化在丰水期与土壤温度呈正相关，而在丰水期与土壤温度不相关。土壤呼吸速率日变化在旱季表现为午休现象。用多项式方程估算土壤碳通量时，应考虑热带干旱森林雨季和旱季的不同函数。
Spatial and seasonal variation in soil respiration rates were investigated in a tropical dry forest in Thailand. The spatial variation was examined at 50 points within a 2-ha plot in the forest floor during the dry and wet seasons. The seasonal and diurnal variations in soil respiration were measured at 16 and 5 points, respectively. The mean soil respiration rate during the wet season was 1041 +/- 542 mg CO2 m(-2) h(-1) (mean +/- SD), which is about twice that during the dry season. Soil respiration rate was negatively correlated with soil water content during the wet season. A polynomial equation using seasonal data describes soil respiration and water content: soil respiration rate increased with soil water content, but started to drop when soil water content exceeded 21%. The diurnal variation in soil respiration rate during the wet season was positively correlated with soil temperature, whereas during the wet season it was not correlated with soil temperature. The diurnal variation in soil respiration rate during the dry season showed a midday depression. The estimation of soil carbon flux with polynomial equations should incorporate different functions for the wet and dry seasons in tropical dry forests.