Trade‐offs in soil carbon protection mechanisms under aerobic and anaerobic conditions

Global Change Biology, Год журнала: 2020, Номер 26(6), С. 3726 - 3737

Опубликована: Март 30, 2020

Oxygen (O2 ) limitation is generally understood to suppress oil carbon (C) decomposition and a key mechanism impacting terrestrial C stocks under global change. Yet, O2 may differentially impact kinetic or thermodynamic versus physicochemical protection mechanisms, challenging our understanding of how soil respond climate-mediated changes in dynamics. Although new litter inputs, release physicochemically protected due iron (Fe) reduction could potentially sustain losses. To test this trade-off, we incubated two disparate upland soils that experience periodic limitation-a tropical rainforest Oxisol temperate cropland Mollisol-with added either aerobic (control) anaerobic conditions for 1 year. Anoxia suppressed total loss by 27% the 41% Mollisol relative control, mainly decrease litter-C decomposition. However, anoxia sustained even increased native soil-C (11.0% vs. 12.4% control 12.5% 5.3% Mollisol, terms initial mass), it stimulated losses metal- mineral-associated C. Solid-state 13 nuclear magnetic resonance spectroscopy demonstrated decreased protein-derived but lignin- carbohydrate-C control. Our results indicate trade-off between kinetic/thermodynamic mechanisms conditions, whereby was compensated more extensive both soils. This challenges common assumption inherently protects illustrates vulnerability events characteristic warmer wetter future climate.

Язык: Английский

---

Delineating the Role of Calcium in the Large‐Scale Distribution of Metal‐Bound Organic Carbon in Soils

Geophysical Research Letters, Год журнала: 2021, Номер 48(10)

Опубликована: Май 4, 2021

Abstract Metal‐bound organic carbon (OC) is vital for the persistence of soil (SOC). However, its relative importance in different land types (e.g., upland vs. wetland) remains unclear. Here by analyzing metal‐bound OC classic citrate‐bicarbonate‐dithionite method (OC CBD ) from 62 soils contrasting environments, we find that constitutes an equally important proportion SOC %) wetlands as uplands. Land‐use type and calcium (Ca) content are best predictors %, likely owing to contribution directly associated with sulfate‐extractable Ca Na2SO4 Ca's bridging aggregating effect on . By further separating , accounts ∼24% Tibetan‐Mongolian grasslands shift S‐shaped mode along pH gradient (6–9). These findings highlight distribution at regional scales.

Язык: Английский

---

Straw returning mediates soil microbial biomass carbon and phosphorus turnover to enhance soil phosphorus availability in a rice-oilseed rape rotation with different soil phosphorus levels

Agriculture Ecosystems & Environment, Год журнала: 2022, Номер 335, С. 107991 - 107991

Опубликована: Май 2, 2022

Язык: Английский

---

Association of Organic Carbon With Reactive Iron Oxides Driven by Soil pH at the Global Scale

Global Biogeochemical Cycles, Год журнала: 2022, Номер 36(1)

Опубликована: Янв. 1, 2022

Abstract Association of organic carbon (C) with iron (Fe) minerals is one important mechanism for long‐term terrestrial C storage. Yet, specific edaphic variables that directly contribute to Fe‐associated across diverse soil types are still unclear. Through analyzing soils from the National Ecological Observatory Network (NEON) and other published data, here we show pH primarily controls globe. in most ranged 0 20 g kg −1 soil, a strong increase 4.2 3.5, but small change > 4.2. A microcosm experiment further showed raising by liming reduced formation an acidic Oxisol. Together, these findings demonstrate dominant role controlling abundance C.

Язык: Английский

---

Microbial autotrophy explains large‐scale soil CO₂ fixation

Global Change Biology, Год журнала: 2022, Номер 29(1), С. 231 - 242

Опубликована: Окт. 13, 2022

Microbial communities play critical roles in fixing carbon from the atmosphere and it soils. However, large-scale variations drivers of these microbial remain poorly understood. Here, we conducted a survey across China found that soil autotrophic organisms are for explaining CO2 fluxes to In particular, showed fixation rates highly correlated those bacteria phototrophic protists. Paddy soils, supporting larger proportion obligate bacterial protist autotrophs, display four-fold over upland forest Precipitation pH, together with key ecological clusters microbes, also played important controlling fixation. Our work provides novel quantification on contribution terrestrial microbes processes at large scale, implications global regulation under climate change.

Язык: Английский

---