Effect of forest structure on the spatial variation in soil respiration in a Bornean tropical rainforest
Effect of forest structure on the spatial variation in soil respiration in a Bornean tropical rainforest
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DOI：
10.1016/j.agrformet.2009.05.007
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发表时间：
2009-10-01
影响因子：
6.2
通讯作者：
Kumagai, Tomo'omi
中科院分区：
文献类型：
--
作者：
Katayama, Ayumi;Kume, Tomonori;Kumagai, Tomo'omi
这项研究的目的是确定解释土壤呼吸空间变化的关键和实际因素，并估计婆罗洲岛非季节性热带雨林的标准土壤呼吸。为此，我们在 2002 年至 2006 年间对 4 公顷研究样地的 40 英寸 x 40 m 子样地的 25 个点进行了土壤呼吸测量，并检查了 4 年来平均土壤呼吸与土壤、根系和森林结构因素相关的空间变化。此外，我们还使用特定的缩放程序检查了子图中测量的土壤呼吸的空间代表性。因此，我们发现土壤呼吸与测量点6 m范围内的平均胸径（DBH）、总断面积和最大DBH等森林结构参数之间存在显着的正相关关系。最重要的因素是测点6 m范围内的平均胸径，它与土壤呼吸呈显着的线性关系。使用导出的线性回归和清单数据集，我们估计了 4 公顷地块规模的土壤呼吸。 4 公顷小区规模估计值（6.0 μ mol m(-2) s(-1)）与子小区规模测量值（5.7 μ mol m(-2) s(-1)）几乎相同。这与使用涡流协方差技术计算的夜间二氧化碳通量大致相当。此外，我们通过与先前文献报道的其他森林在土壤碳平衡方面的比较，讨论了该地点的林分尺度土壤呼吸特征。相对于发生的凋落物量，我们所在地的土壤呼吸明显大于其他热带和温带森林的土壤呼吸，这可能是由于挺水树木的地下碳分配总量较大。总体而言，本研究表明，具有较大胸径的挺水树木的排列及其地下碳分配可能是控制热带雨林土壤呼吸空间变化的主要因素。 (C) 2009 Elsevier B.V. 保留所有权利。
This study was undertaken to identify critical and practical factors explaining spatial variations in soil respiration and to estimate stand-scale soil respiration in an aseasonal tropical rainforest on Borneo Island. To this aim, we conducted soil respiration measurements at 25 points in a 40 in x 40 m subplot of a 4 ha study plot between 2002 and 2006, and examined the spatial variation in soil respiration averaged over the 4 years in relation to soil, root, and forest structural factors. In addition, we examined the spatial representativeness of soil respiration measured in the subplot using a specific scaling procedure. Consequently, we found significant positive correlation between the soil respiration and forest structural parameters such as the mean diameter at breast height (DBH), total basal area, and maximum DBH within 6 m of the measurement points. The most important factor was the mean DBH within 6 m of the measurement points, which had a significant linear relationship with soil respiration. Using the derived linear regression and an inventory dataset, we estimated the 4 ha plot-scale soil respiration. The 4 ha plot-scale estimation (6.0 mu mol m(-2) s(-1)) was nearly identical to the subplot-scale measurements (5.7 mu mol m(-2) s(-1)). which were roughly comparable to the nocturnal CO2 fluxes calculated using the eddy covariance technique. In addition, we discuss characteristics of the stand-scale soil respiration at this site by comparing with those of other forests reported in previous literature in terms of the soil C balance. Soil respiration at our site was noticeably greater, relative to the incident litterfall amount, than soil respiration in other tropical and temperate forests probably owing to the larger total belowground C allocation by emergent trees. Overall, this study suggests the arrangement of emergent trees with larger DBH and their belowground C allocation could be primary factors controlling spatial variations in soil respiration in the tropical rainforest. (C) 2009 Elsevier B.V. All rights reserved.