A representation of the phosphorus cycle for ORCHIDEE (revision 4520)
A representation of the phosphorus cycle for ORCHIDEE (revision 4520)
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DOI：
10.5194/gmd-10-3745-2017
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发表时间：
2017-10-12
影响因子：
5.1
通讯作者：
Ciais, Philippe
中科院分区：
文献类型：
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作者：
Goll, Daniel S.;Vuichard, Nicolas;Ciais, Philippe
尽管关于氮和磷供应对未来土地碳吸收的重要性存在广泛的科学争论，但陆地表面模型很少纳入陆地磷循环及其与碳循环的相互作用。我们描述了ORCHIDEE陆地表面模型的陆地磷循环表示，并根据夏威夷土壤形成时间序列的养分操纵实验数据对其进行了评估。ORCHIDEE解释了植被营养状态对组织养分浓度、光合作用、植物生长、生物量分配、生化（磷酸酶介导）矿化和生物固氮的影响。凋落物养分含量（质量）的变化影响分解的碳利用效率，进而影响植被的养分有效性。该模型明确地考虑了根区磷消耗作为根磷吸收和磷从土壤到根表面运输的函数。该模型捕获了土壤发育早期（300年）和后期（4.1百万年数）植被叶片化学计量学的观测差异。净初级生产力对添加氮、磷或两者同时增加的敏感性的对比一般可由模型再现。结果表明，该模型模拟了氮胁迫缓解对叶水平生产力的优先刺激，而磷胁迫缓解对叶水平生产力和叶面积指数的同等刺激。模型中的养分利用效率低于观测值，主要是由于木质生物量的养分含量和周转存在偏差。结果表明，ORCHIDEE能够沿土壤发育时间序列重现由氮向磷限制的净初级生产力的转变，以及净初级生产力对养分添加的对比响应。
Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the ORCHIDEE land surface model, and evaluate it with data from nutrient manipulation experiments along a soil formation chronosequence in Hawaii.ORCHIDEE accounts for the influence of the nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated) mineralization, and biological nitrogen fixation. Changes in the nutrient content (quality) of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from the soil to the root surface.The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300-year) and a late (4.1 Myr) stage of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus, or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower than observed primarily due to biases in the nutrient content and turnover of woody biomass.We conclude that ORCHIDEE is able to reproduce the shift from nitrogen to phosphorus limited net primary productivity along the soil development chronosequence, as well as the contrasting responses of net primary productivity to nutrient addition.