Soil carbon and nitrogen mineralization: Theory and models across scales

雩风三日

Soil carbon and nitrogen mineralization: Theory and models across scales
土壤碳氮矿化:跨尺度理论与模型

      In the last 80 years, a number of mathematical models of different level of complexity have been developed to describe biogeochemical processes in soils, spanning spatial scales from few mm to thousands of km and temporal scales from hours to centuries. Most of these models are based on kinetic and stoichiometric laws that constrain elemental cycling within the soil and the nutrient and carbon exchange with vegetation and the atmosphere. While biogeochemical model performance has been previously assessed in other reviews, less attention has been devoted to the mathematical features of the models, and how these are related to spatial and temporal scales. In this review, we consider w250 biogeochemical models, highlighting similarities in their theoretical frameworks and illustrating how their mathematical structure and formulation are related to the spatial and temporal scales of the model applications. Our analysis shows that similar kinetic and stoichiometric laws, formulated to mechanistically represent the complex underlying biochemical constraints, are common to most models, providing a basis for their classification. Moreover, a historic analysis reveals that the complexity and degree and number of nonlinearities generally increased with date, while they decreased with increasing spatial and temporal scale of interest. We also found that mathematical formulations specifically developed for certain scales (e.g., first order decay rates assumed in yearly time scale decomposition models) often tend to be used also at other spatial and temporal scales different from the original ones,possibly resulting in inconsistencies between theoretical formulations and model application. It is thus critical that future modeling efforts carefully account for the scale-dependence of their mathematical formulations, especially when applied to a wide range of scales.

  近80年来，人们建立了许多不同复杂程度的数学模型，其空间尺度从几毫米到几千公里，时间尺度从几小时到几个世纪。这些模型大多基于动力学和化学计量学定律，这些定律限制了土壤中元素的循环以及与植被和大气之间的养分和碳交换。虽然生物地球化学模型的性能已经在其他评论中得到了评估，但很少关注模型的数学特征，以及这些特征与空间和时间尺度的关系。本文以w250生物地球化学模型为例，重点介绍了w250生物地球化学模型在理论框架上的相似性，并阐述了w250生物地球化学模型的数学结构和公式与模型应用的时空尺度之间的关系。我们的分析表明，类似的动力学和化学计量定律，机械地表示复杂的潜在生化约束，是大多数模型的共同之处，为它们的分类提供了基础。此外，历史分析表明，非线性的复杂性、程度和数量通常随时间的增加而增加，而随着兴趣的空间和时间尺度的增加而减少。我们还发现,数学公式专门为特定尺度发展(例如,一阶衰减率假设每年在时间尺度分解模型)往往也使用在其他时空尺度与原来的不同,可能导致理论公式和模型应用程序之间的矛盾。因此，未来的建模工作必须仔细考虑其数学公式的尺度依赖性，特别是当应用于广泛的尺度时。

Keywords:Decomposition models；Stoichiometry；Model classification；Mineralization–immobilization turnover；Microbial biomass；Nutrient limitation；Heterotrophic respiration；Decomposition；Spatial and temporal scales

关键词:分解模型，化学计量模型，分类，矿化固定周转，微生物生物量，养分限制，异养呼吸分解，时空尺度abstract