Simulating SOC changes in 11 land use change chronosequences from the Brazilian Amazon with RothC and Century models
Simulating SOC changes in 11 land use change chronosequences from the Brazilian Amazon with RothC and Century models
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DOI：
10.1016/j.agee.2007.01.007
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发表时间：
2007-09-01
影响因子：
6.6
通讯作者：
Cerri, Carlos C.
中科院分区：
文献类型：
--
作者：
Cerri, Carlos E. P.;Easter, Mark;Cerri, Carlos C.
巴西亚马逊地区的土地利用和土地覆盖变化对区域和全球碳循环具有重要影响。在该地区的大部分地区，牧场是这片曾经的林地最大的单一用途（约70%）。本研究的主要目的是评估RothC和Century模型在估算巴西亚马逊地区森林-牧场条件下土壤有机碳（SOC）变化的准确性。我们利用世纪生态系统模型（Century 4.0）和Rothamsted C模型（RothC 26.3）对11个特定地点的“森林到牧场”时序序列数据进行了分析。这些模型预测，森林砍伐和向管理良好的牧场的转变将导致土壤C储量（0-20厘米深度）的初步下降，随后在大多数情况下缓慢上升至超过原始森林下的水平。这种模式的一个例外是Suia-Missu的时间顺序，这是退化的牧场。在其他三个时间序列中，放牧下土壤C的恢复似乎仅与以前的森林下大致相同。采用统计检验来确定11个时间序列中所有地点的模拟SOC种群与观测种群之间的一致性水平。与现有的实测数据相比，该模型还提供了0-10 cm土层3个时间序列微生物生物量C的合理估计（相关系数= 0.8）。Century模型充分地预测了6个时间序列中δ C-13的幅度和总体趋势，这些序列中有测量到的813c数据。本研究对模型性能进行了独立测试，因为没有对模型进行调整以产生输出。我们的研究结果表明，建模技术可以成功地用于监测土壤C储量和变化，从而既可以识别土壤中的当前模式，又可以预测未来的条件。研究结果不仅用于评价土壤碳动态，而且还用于指出巴西亚马逊地区土壤碳的固存机会。此外，在这些“森林到牧场”系统中的建模研究具有重要的应用，例如，在国家温室气体清单中计算土地利用变化产生的CO排放量。（2007 Elsevier B.V.）版权所有
Land use and land cover changes in the Brazilian Amazon have major implications for regional and global carbon (C) cycling. Cattle pasture represents the largest single use (about 70%) of this once-forested land in most of the region. The main objective of this study was to evaluate the accuracy of the RothC and Century models at estimating soil organic C (SOC) changes under forest-to-pasture conditions in the Brazilian Amazon. We used data from 11 site-specific 'forest to pasture' chronosequences with the Century Ecosystem Model (Century 4.0) and the Rothamsted C Model (RothC 26.3). The models predicted that forest clearance and conversion to well managed pasture would cause an initial decline in soil C stocks (0-20 cm depth), followed in the majority of cases by a slow rise to levels exceeding those under native forest. One exception to this pattern was a chronosequence in Suia-Missu, which is under degraded pasture. In three other chronosequences the recovery of soil C under pasture appeared to be only to about the same level as under the previous forest. Statistical tests were applied to determine levels of agreement between simulated SOC stocks and observed stocks for all the sites within the 11 chronosequences. The models also provided reasonable estimates (coefficient of correlation = 0.8) of the microbial biomass C in the 0-10 cm soil layer for three chronosequences, when compared with available measured data. The Century model adequately predicted the magnitude and the overall trend in delta C-13 for the six chronosequences where measured 813 C data were available. This study gave independent tests of model performance, as no adjustments were made to the models to generate outputs. Our results suggest that modelling techniques can be successfully used for monitoring soil C stocks and changes, allowing both the identification of current patterns in the soil and the projection of future conditions. Results were used and discussed not only to evaluate soil C dynamics but also to indicate soil C sequestration opportunities for the Brazilian Amazon region. Moreover, modelling studies in these 'forest to pasture' systems have important applications, for example, the calculation of CO, emissions from land use change in national greenhouse gas inventories. (0 2007 Elsevier B.V. All rights reserved.