GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes
GOLUM-CNP v1.0: a data-driven modeling of carbon, nitrogen and phosphorus cycles in major terrestrial biomes
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DOI：
10.5194/gmd-11-3903-2018
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发表时间：
2018-09
影响因子：
5.1
通讯作者：
Yilong Wang;P. Ciais;D. Goll;Yuanyuan Huang;Yiqi Luo;Ying-Ping Wang;A. Anthony Bloom;G. Broquet-G.
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文献类型：
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作者：
Yilong Wang;P. Ciais;D. Goll;Yuanyuan Huang;Yiqi Luo;Ying-Ping Wang;A. Anthony Bloom;G. Broquet-G.
摘要。全球陆地氮(N)和磷(P)循环与全球碳(C)循环在净初级生产（NPP）、植物碳分配和土壤有机质分解方面是耦合的，但N和P具有不同的输入和损失途径。由于缺乏用于评估模型的一致的全球数据，目前的c -营养物模型对营养物池大小、通量和周转率的估计存在很大的不确定性。在这项研究中，我们提出了一个新的模型-数据融合框架，称为全球基于观测的土地生态系统碳、氮和磷利用模型（GOLUM-CNP），该模型将碳数据模型框架（CARDAMOM）数据约束的c循环分析与空间明确的数据驱动的N和P输入和损失估计以及观测到的化学计量比相结合。我们计算了大型生物群落的稳态N-和p -池大小和通量。我们的研究表明，在大多数森林生态系统中，来自生物固定和沉积的新氮输入占植物总吸收的20%左右，但在北方森林和草原中所占的比例较小。来自大气沉积和岩石风化的新P输入比新N输入提供的植物吸收总量的比例要小得多，这表明生态系统内部P循环对支持植物生长的重要性。养分利用效率，定义为总初级生产（GPP）与植物养分吸收的比率，根据我们的模型结果进行诊断，并在生物群系之间进行比较。热带森林的氮利用效率最低，磷利用效率最高。敏感性和不确定性分析表明，叶片、根和木材的npp分配分数对养分利用效率估算的不确定性贡献最大。修正npp分配分数的偏差产生了从热带到北方生态系统的更合理的N和P利用效率梯度，并强调了准确测量C分配对理解N和P循环的关键作用。
Abstract. Global terrestrial nitrogen (N) and phosphorus (P) cycles are coupled to the global carbon (C) cycle for net primary production (NPP), plant C allocation, and decomposition of soil organic matter, but N and P have distinct pathways of inputs and losses. Current C-nutrient models exhibit large uncertainties in their estimates of pool sizes, fluxes, and turnover rates of nutrients, due to a lack of consistent global data for evaluating the models. In this study, we present a new model–data fusion framework called the Global Observation-based Land-ecosystems Utilization Model of Carbon, Nitrogen and Phosphorus (GOLUM-CNP) that combines the CARbon DAta MOdel fraMework (CARDAMOM) data-constrained C-cycle analysis with spatially explicit data-driven estimates of N and P inputs and losses and with observed stoichiometric ratios. We calculated the steady-state N- and P-pool sizes and fluxes globally for large biomes. Our study showed that new N inputs from biological fixation and deposition supplied >20 % of total plant uptake in most forest ecosystems but accounted for smaller fractions in boreal forests and grasslands. New P inputs from atmospheric deposition and rock weathering supplied a much smaller fraction of total plant uptake than new N inputs, indicating the importance of internal P recycling within ecosystems to support plant growth. Nutrient-use efficiency, defined as the ratio of gross primary production (GPP) to plant nutrient uptake, were diagnosed from our model results and compared between biomes. Tropical forests had the lowest N-use efficiency and the highest P-use efficiency of the forest biomes. An analysis of sensitivity and uncertainty indicated that the NPP-allocation fractions to leaves, roots, and wood contributed the most to the uncertainties in the estimates of nutrient-use efficiencies. Correcting for biases in NPP-allocation fractions produced more plausible gradients of N- and P-use efficiencies from tropical to boreal ecosystems and highlighted the critical role of accurate measurements of C allocation for understanding the N and P cycles.