Romul_Hum model of soil organic matter formation coupled with soil biota activity. I. Problem formulation, model description, and testing
| Autor: | Vladimir Shanin, Elena Zubkova, Maxim Shashkov, Cindy Shaw, S. S. Bykhovets, Alexander Komarov, Marina Nadporozhskaya, Oleg Chertov, Irina Priputina, Pavel Frolov, Pavel Grabarnik |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010504 meteorology & atmospheric sciences
biology Ecological Modeling Soil organic matter Soil biology Earthworm Soil science 04 agricultural and veterinary sciences Soil carbon Carbon sequestration biology.organism_classification 01 natural sciences Humus Soil respiration 040103 agronomy & agriculture 0401 agriculture forestry and fisheries Environmental science Soil ecology 0105 earth and related environmental sciences |
| Zdroj: | Ecological Modelling. 345:113-124 |
| ISSN: | 0304-3800 |
| Popis: | For many decades in the late 20th century, the processes involved in the formation of soil organic matter (SOM) (also known as humification) constituted one of the most important areas of scientific inquiry in soil science. However, these processes have not been included in modern models of SOM dynamics, despite their relevance to quantifying carbon stabilisation (i.e., sequestration) in soil. Furthermore, modern models have focussed on mineralisation processes (e.g., mainly microbial heterotrophic respiration) and have not included the important effects of soil fauna that are known as key agents of SOM formation. To address these issues, we developed a modelling approach predicated on the existence of definable stoichiometric relations among the processes leading to SOM formation that are mediated by soil biota (e.g., correlations among biotic respiration, production of faunal excrement, and necromass as sources of SOM formation). Soil respiration, a core rate variable in all SOM models, was associated with the production of faunal by-products in soil food webs as precursors of stable SOM, specifically micro- and meso-faunal excrement, necromass, and earthworm casts. We developed a food-web based module, using a synthesis of decades of published data, to describe micro- and meso-faunal excrement and necromass production. We developed a separate module for anecic earthworms, with explicit representation of processes related to fresh casts. The contributions of these two modules were compiled and integrated with the ROMUL model of SOM dynamics, without changing the structure of the original model. These modules enabled calculation of the proportional contribution of faunal by-products to humification (i.e., recalcitrant SOM formation) and carbon sequestration. Testing of the new version of the model, known as Romul_Hum, showed consistent accumulation of faunal by-products in the “final” SOM fractions: the well-decomposed SOM of the organic soil horizons and the stable SOM of the mineral soil. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect