Implications of a large global root biomass for carbon sink estimates and for soil carbon dynamics
Implications of a large global root biomass for carbon sink estimates and for soil carbon dynamics
复制标题
DOI：
10.1098/rspb.2007.1012
复制
发表时间：
2007-11
期刊：
影响因子：
--
通讯作者：
D. Robinson
中科院分区：
文献类型：
--
作者：
D. Robinson
最近的证据表明，植物储存在地下的碳(C)比现有的估计要多得多。本研究探讨了对生物群系碳库大小和全球碳通量的影响。它预测根C池至少有268 Pg，比之前估计的要大68%。尽管仍然是一个精度较低的估计（由于生物群落尺度测量的不确定性），但如此庞大的全球根C库意味着更强的陆地C汇，特别是在热带和温带森林、灌木和热带草原。根据修正后的碳清单预测的陆地碳汇为2.7 Pg / yr - 1。在与全球碳通量相关的不确定性范围内，这比目前的估计值大0.1 Pg / yr−1，但与从碳平衡估计的较小的汇（2.4 Pg / yr−1）相冲突。然而，如果假设全球土壤C以每年0.4-0.7%的速度下降，那么从碳库存和碳平衡中得出的汇估计值与土壤C的长期区域损失率一致。无论是陆地碳汇增强还是土壤碳流失广泛，都认为应该重新评估全球碳循环的这些特征，以提高全球和生物群系尺度上碳通量和碳库估算的准确性和精度。
Recent evidence suggests that significantly more plant carbon (C) is stored belowground than existing estimates indicate. This study explores the implications for biome C pool sizes and global C fluxes. It predicts a root C pool of at least 268 Pg, 68% larger than previously thought. Although still a low-precision estimate (owing to the uncertainties of biome-scale measurements), a global root C pool this large implies stronger land C sinks, particularly in tropical and temperate forests, shrubland and savanna. The land sink predicted from revised C inventories is 2.7 Pg yr−1. This is 0.1 Pg yr−1 larger than current estimates, within the uncertainties associated with global C fluxes, but conflicting with a smaller sink (2.4 Pg yr−1) estimated from C balance. Sink estimates derived from C inventories and C balance match, however, if global soil C is assumed to be declining by 0.4–0.7% yr−1, rates that agree with long-term regional rates of soil C loss. Either possibility, a stronger land C sink or widespread soil C loss, argues that these features of the global C cycle should be reassessed to improve the accuracy and precision of C flux and pool estimates at both global and biome scales.