Little is known about carbon budgets for tropical and subtropical montane cloud forest (TMCF) ecosystems. Information about the soil CO efflux from these ecosystems is particularly scarce, although they have been shown to have special hydrological regimes which might be important in controlling soil respiration. In this study, we used an automatic chamber system to measure soil respiration rates at the Chi-Lan Mountain forest site. The half-hourly dataset was used for analyzing the controlling factors and mechanisms of soil respiration. A manipulation experiment was conducted in the field by applying 3-fold and 1-fold aboveground litter to the soil surface and measuring the respective soil respiration rates using the static alkali chamber method. The results showed that soil respiration rates have a positive exponential correlation with soil temperature and a negative exponential correlation with soil water content. An empirical model relating soil respiration (R s) to soil temperature (T) and soil water content (i) is R s =-0.095+e.ii.p#Te.##i with R po =0.83. The annual soil respiration rate calculated using this model was 176gCmpo yp#. This extremely low value might be caused by the permanently high soil moisture and the relative lower mean annual temperature compared to other sites that receive similar amounts of precipitation. The 3-fold and 1-fold litter treatments resulted in significantly higher soil CO efflux compared to the chambers with no litter. The magnitude of difference diminished to negligible levels 6 months after treatment. About 10% of the annual soil respiration was contributed by the mineralization of fresh aboveground litter. The carbon mass loss of the decomposing litter during the first 6 months was mainly due to leaching of dissolved organic carbon (75%) and secondarily due to mineralization of CO. From the results of this study, we hypothesized that the TMCFs may be vulnerable to global warming since the drying of the soil may change the soil from being a carbon sink to being a carbon source, thereby releasing soil organic carbon that had been stored for a long period of time.
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机译：对于热带和亚热带山地云雾森林（TMCF）生态系统的碳预算知之甚少。尽管这些生态系统具有特殊的水文状况，但对于控制土壤呼吸可能很重要，但有关这些生态系统中土壤CO外排的信息特别稀少。在这项研究中，我们使用了一个自动室系统来测量赤岚山森林站点的土壤呼吸速率。半小时数据集用于分析土壤呼吸的控制因素和机理。通过在地面上施用3倍和1倍地上的凋落物，并使用静态碱室法测量相应的土壤呼吸速率，在野外进行了一项操作实验。结果表明，土壤呼吸速率与土壤温度呈正相关，与土壤含水量呈负相关。将土壤呼吸（R s）与土壤温度（T）和土壤水分（i）关联的经验模型为R s = -0.095 + e.ii.p＃Te。## i，R po = 0.83。使用该模型计算的年土壤呼吸速率为176gCmpo yp＃。与其他降水量相似的地点相比，这种极低的值可能是由于土壤湿度过高和年平均温度相对较低所致。 3倍和1倍垃圾处理与没有垃圾的处理箱相比，可显着提高土壤CO外排量。治疗后6个月，差异的大小减小到可以忽略的水平。新鲜的地上垃圾的矿化作用贡献了每年约10％的土壤呼吸作用。前6个月分解垃圾的碳质量损失主要是由于溶解有机碳的浸出（75％），其次是由于CO的矿化。根据这项研究的结果，我们假设TMCF可能易受由于土壤干燥导致全球变暖，可能会使土壤从碳汇变为碳源，从而释放已长期存储的土壤有机碳。
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