Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2
Carbon residence time dominates uncertainty in terrestrial vegetation responses to future climate and atmospheric CO2
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DOI：
10.1073/pnas.1222477110
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发表时间：
2014-03-04
影响因子：
11.1
通讯作者：
Woodward, F. Ian
中科院分区：
文献类型：
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作者：
Friend, Andrew D.;Lucht, Wolfgang;Woodward, F. Ian
未来的气候变化和大气二氧化碳的增加预计将导致全球大部分陆地表面的植被结构和功能发生重大变化。使用七个全球植被模型分析了在温室气体浓度变化的所有四个典型浓度路径情景下运行的一系列大气环流模型模拟的对未来气候的可能响应。所有110个模拟都预测全球植被碳将增加到2100个，但不同的植被模型有很大差异。例如，在全球陆地表面变暖的4摄氏度(510-758ppm的二氧化碳)下，植被碳增加52-477 pg C(平均224 pg C)，这主要是由于光合作用的二氧化碳施肥。模拟结果表明，北方森林、亚马逊西部、中非、中国西部和东南亚的大部分地区都出现了大幅增加，而北美西南部、南美洲中部、地中海南部、非洲西南部和澳大利亚西南部则出现了减少。四个植被模型显示了4摄氏度变暖的不连续性，表明了对生产力和生物量的积极和消极影响平衡的全球阈值。与以前的全球植被模型研究不同，我们强调了碳停留时间预测变化中的不确定性的重要性。我们发现，当所有七个模式都被考虑为一个典型的浓度路径x大气环流模式组合时，这种不确定性对模拟的植被碳变化的解释比仅对净初级生产力的响应多30%，对于非Hybri4模式，增加到151%。建议改变研究重点，从生产转向结构动态和人口统计过程。
Future climate change and increasing atmospheric CO2 are expected to cause major changes in vegetation structure and function over large fractions of the global land surface. Seven global vegetation models are used to analyze possible responses to future climate simulated by a range of general circulation models run under all four representative concentration pathway scenarios of changing concentrations of greenhouse gases. All 110 simulations predict an increase in global vegetation carbon to 2100, but with substantial variation between vegetation models. For example, at 4 C of global land surface warming (510-758 ppm of CO2), vegetation carbon increases by 52-477 Pg C (224 Pg C mean), mainly due to CO2 fertilization of photosynthesis. Simulations agree on large regional increases across much of the boreal forest, western Amazonia, central Africa, western China, and southeast Asia, with reductions across southwestern North America, central South America, southern Mediterranean areas, southwestern Africa, and southwestern Australia. Four vegetation models display discontinuities across 4 degrees C of warming, indicating global thresholds in the balance of positive and negative influences on productivity and biomass. In contrast to previous global vegetation model studies, we emphasize the importance of uncertainties in projected changes in carbon residence times. We find, when all seven models are considered for one representative concentration pathway x general circulation model combination, such uncertainties explain 30% more variation in modeled vegetation carbon change than responses of net primary productivity alone, increasing to 151% for non-HYBRID4 models. A change in research priorities away from production and toward structural dynamics and demographic processes is recommended.