Respiration from coarse wood litter in central Amazon forests
Respiration from coarse wood litter in central Amazon forests
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DOI：
10.1023/a:1006473530673
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发表时间：
2001-01-01
期刊：
影响因子：
4
通讯作者：
Nobre, AD
中科院分区：
文献类型：
--
作者：
Chambers, JQ;Schimel, JP;Nobre, AD
在亚马逊中部森林中研究了粗糙垃圾（树干和直径 > 10 厘米的大树枝）的呼吸。呼吸速率变化几乎两个数量级（1.003-0.014 mug C g(-1) C min(-1)，n = 61），并且与木材密度（r(adj)(2) = 0.42）和水分含量（r(adj)(2) = 0.39）显着相关。从附近牧场采集的其他样本表明，木材含水量是控制不同地点呼吸速率的最重要因素（r(adj)(2) = 0.65）。根据平均粗枯落物密度和含水量，呼吸作用导致的平均长期碳损失率为0.13 yr(-1)（95%预测区间（PI）范围= 0.11-0.15 yr(-1)）。将平均呼吸速率与先前研究的平均质量损失（分解）速率进行比较，粗垃圾向大气中的呼吸排放预计占总碳损失的 76% (95% PI = 65-88%)，或约 1.9 (95% PI = 1.6-2.2) Mg C ha(-1) yr(-) (1)。最佳呼吸活性对应于约2.5 g H2O g(-1)干木，并且严格限制呼吸至<0.5 g H2O g(-1)干木。亚马逊中部森林粗碎物的呼吸量与分解的细小表面碎物（例如树叶、树枝）相当，并且是表征异养呼吸预算和净生态系统交换（NEE）时的重要碳循环组成部分。
Respiration from coarse litter (trunks and large branches > 10 cm diameter) was studied in central Amazon forests. Respiration rates varied over almost two orders of magnitude (1.003-0.014 mug C g(-1) C min(-1), n = 61), and were significantly correlated with wood density (r(adj)(2) = 0.42), and moisture content (r(adj)(2) = 0.39). Additional samples taken from a nearby pasture indicated that wood moisture content was the most important factor controlling respiration rates across sites (r(adj)(2) = 0.65). Based on average coarse litter wood density and moisture content, the mean long-term carbon loss rate due to respiration was estimated to be 0.13 yr(-1) (range of 95% prediction interval (PI) = 0.11-0.15 yr(-1)). Comparing mean respiration rate with mean mass loss (decomposition) rate from a previous study, respiratory emissions to the atmosphere from coarse litter were predicted to be 76% (95% PI = 65-88%) of total carbon loss, or about 1.9 (95% PI = 1.6-2.2) Mg C ha(-1) yr(-) (1). Optimum respiration activity corresponded to about 2.5 g H2O g(-1) dry wood, and severely restricted respiration to < 0.5 g H2O g(-1) dry wood. Respiration from coarse litter in central Amazon forests is comparable in magnitude to decomposing fine surface litter (e.g. leaves, twigs) and is an important carbon cycling component when characterizing heterotrophic respiration budgets and net ecosystem exchange (NEE).