Model inter-comparison between statistical and dynamic model assessments of the long-term stability of blanket peat in Great Britain (1940-2099)
Model inter-comparison between statistical and dynamic model assessments of the long-term stability of blanket peat in Great Britain (1940-2099)
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DOI：
10.3354/cr00974
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发表时间：
2010-01-01
期刊：
影响因子：
1.1
通讯作者：
Worrall, F.
中科院分区：
文献类型：
--
作者：
Clark, J. M.;Billett, M. F.;Worrall, F.
我们比较了 3 个基于动态过程的模型（DM：ECOSSE、MILLENNIA 和 Durham Carbon 模型）和 9 个生物气候包络模型（BCEM；包括 BBOG ensemble 和 PEATSTASH）的输出，范围从简单阈值到半基于过程的模型。使用历史气候数据和支持 UKCP09 的 11-RCM（区域气候模型）集合的中等 (A1B) 排放情景下的气候预测，在 4 个英国泥炭地地点进行了模型模拟。模型显示，覆盖泥炭地很容易受到预计气候变化的影响；然而，模型之间以及站点之间的预测有所不同。所有 BCEM 都预测与覆盖泥炭相关的气候从存在转变为不存在，其中年总降水量最低的地点最接近存在/不存在阈值。 DM 表现出更加可变的反应。 ECOSSE 预测，到本世纪末，净碳汇量将下降，并转向净碳源。达勒姆碳模型预测净碳汇强度下降幅度较小，但不会转向净碳源。 MILLENNIA 预测净碳汇总体略有增加。与 BCEM 预测相反，DM 预测气温最低和年总降水量最大的地点显示出最大的碳汇变化。在该模型相互比较中，响应气候变化预测的模型输出的最大变化不是在 BCEM 和 DM 之间，而是在 DM 本身之间，因为对土壤有机质库和其他过程中的分解进行建模的方法不同。响应信号的差异对未来的气候反馈、气候政策和泥炭地管理具有重大影响。加强数据收集，特别是监测泥炭地对当前变化的反应，将显着改善模型开发和未来变化的预测。
We compared output from 3 dynamic process-based models (DMs: ECOSSE, MILLENNIA and the Durham Carbon Model) and 9 bioclimatic envelope models (BCEMs; including BBOG ensemble and PEATSTASH) ranging from simple threshold to semi-process-based models. Model simulations were run at 4 British peatland sites using historical climate data and climate projections under a medium (A1B) emissions scenario from the 11-RCM (regional climate model) ensemble underpinning UKCP09. The models showed that blanket peatlands are vulnerable to projected climate change; however, predictions varied between models as well as between sites. All BCEMs predicted a shift from presence to absence of a climate associated with blanket peat, where the sites with the lowest total annual precipitation were closest to the presence/absence threshold. DMs showed a more variable response. ECOSSE predicted a decline in net C sink and shift to net C source by the end of this century. The Durham Carbon Model predicted a smaller decline in the net C sink strength, but no shift to net C source. MILLENNIA predicted a slight overall increase in the net C sink. In contrast to the BCEM projections, the DMs predicted that the sites with coolest temperatures and greatest total annual precipitation showed the largest change in carbon sinks. In this model inter-comparison, the greatest variation in model output in response to climate change projections was not between the BCEMs and DMs but between the DMs themselves, because of different approaches to modelling soil organic matter pools and decomposition amongst other processes. The difference in the sign of the response has major implications for future climate feedbacks, climate policy and peatland management. Enhanced data collection, in particular monitoring peatland response to current change, would significantly improve model development and projections of future change.