Impact of ecohydrological fluctuations on iron-redox cycling

TitleImpact of ecohydrological fluctuations on iron-redox cycling
Publication TypeJournal Article
Year of Publication2019
AuthorsCalabrese, S, Porporato, A
JournalSoil Biology and Biochemistry
Pagination188 - 195
KeywordsHydrologic control, Iron and carbon model, Plant uptake, Soil iron redox, Soil moisture variability
AbstractBecause of its interaction with plants, carbon decomposition, and soil properties, soil iron cycle has been recognized as an important player in the carbon and other biogeochemical cycles. The impact of the hydrologic cycle and plants on it, however, remains largely unexplored. Here we focus on terrestrial ecosystems and develop a dynamical system to analyze the coupling between iron and carbon dynamics in the soil root zone as driven by fluctuations in soil moisture. Particular emphasis is placed on the modeling of the soil organic matter, the Fe-reducing population, the iron Fe2+-Fe3+ cycling, and the soil moisture level, which controls the redox rates. Informed by laboratory and field measurements from a tropical forest, our results suggest that soil moisture and litterfall rates are the primary drivers of iron fluctuations at daily-to-seasonal temporal scales. We also emphasize the important role of soil iron cycle in the decomposition of the organic matter.