The soil microbial carbon pump: From conceptual insights to empirical assessments

Global Change Biology, Год журнала: 2020, Номер 26(11), С. 6032 - 6039

Опубликована: Авг. 26, 2020

Abstract The global soil carbon (C) pool is massive, so relatively small changes in organic (SOC) stocks can significantly alter atmospheric C and climate. recently proposed concept of the microbial pump (MCP) emphasizes active role microbes SOC storage by integrating continual transformation from labile to persistent anabolic forms. However, has not been evaluated with data. Here, we combine datasets, including necromass biomarker amino sugars SOC, two long‐term agricultural field studies conducted large United States bioenergy research programs. We interrogate MCP investigating asynchronous responses land‐use change. Microbial appeared preferentially accumulate be dominant contributor accrual diversified perennial crops. Specifically, ~92% additional enhanced plant diversity was estimated C, >76% transition annual crops necromass. This suggests that stimulated agroecosystems. further delineate suggest parameters—soil capacity efficacy —reflecting conversion into contribution respectively, should serve as valuable metrics for future evaluating under alternative management changing climates.

Язык: Английский

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Changes in plant inputs alter soil carbon and microbial communities in forest ecosystems

Global Change Biology, Год журнала: 2022, Номер 28(10), С. 3426 - 3440

Опубликована: Янв. 29, 2022

Global changes can alter plant inputs from both above- and belowground, which, thus, may differently affect soil carbon microbial communities. However, the general patterns of how input them in forests remain unclear. By conducting a meta-analysis 3193 observations 166 experiments worldwide, we found that alterations aboveground litter and/or root had profound effects on communities forest ecosystems. Litter addition stimulated organic (SOC) pools biomass, whereas removal litter, roots or (no inputs) decreased them. The increased SOC under suggested benefit sequestration despite accelerated decomposition. Unlike removal, no altered particulate carbon, all detrital treatments did not significantly change mineral-associated carbon. In addition, contrastingly community, with shifting it toward fungi, bacteria. Furthermore, responses biomass to positively correlated rate total input, suggesting quantity is critical controller belowground processes. Taken together, these findings provide insights into understanding productivity allocation affects cycling, functioning ecosystems global changes. Future studies take full advantage existing detritus should focus relative roles forming its fractions.

Язык: Английский

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Decomposition and transformations along the continuum from litter to soil organic matter in forest soils

Forest Ecology and Management, Год журнала: 2021, Номер 498, С. 119522 - 119522

Опубликована: Июль 31, 2021

Until recently, the processes of litter decomposition and soil organic matter formation in forests have been studied isolation, which has hindered development a comprehensive understanding entire process. The last decade brought considerable progress this scientific endeavour response to challenge sequester atmospheric C forest soils. In paper we review key recent developments field describe our current collective transformation pathways ecosystems. Compelling evidence that most slow-cycling SOM microbially transformed forces us rethink standard technique measuring mass remaining litterbags during incubation indicate rates. Rather than indicating remains undecomposed, these measurements reflect net outcome two simultaneous processes: plant material accumulation microbial faunal products. Measurement both pools, rather just total is necessary understand processes. For example, apparent retarding effect available N on loss late-stage may actually result from promoting production biomass necromass, thereby increasing products decay. We recommend referring as ‘net remaining’ or ‘residue mass’ ‘litter mass’, acknowledge its changing composition proceeds. Decomposition with abundant detritivorous meso- macrofauna remain poorly understood consequence inability litterbag capture their influences (even differing mesh sizes). Long-term studies monitoring faecal subsequent transformations are urgently needed. Roots mycorrhizal fungal hyphae important sources SOM, including stable SOM. Fine roots (orders 1 2) decompose particularly slowly, do some hyphae, attributed cell-wall constituents such lignins, melanin glycoproteins. Convergence curves litters initially quickly slowly indicates leaf litter, root residues large labile contents can generate much recalcitrant litters. Transformation into follow many pathways, depending characteristics site. Key site properties influence biotic community present together determine pathway follows As such, occur along continuum between situations aboveground mainly humus accumulates surface, partially decomposed transferred mineral via bioturbation. Predicting likely should inform decisions how measure interpret particular

Язык: Английский

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Grazing and ecosystem service delivery in global drylands

Science, Год журнала: 2022, Номер 378(6622), С. 915 - 920

Опубликована: Ноя. 24, 2022

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that soil, are critical to explain delivery fundamental drylands Increasing pressure reduced service in warmer species-poor drylands, whereas positive effects were observed colder species-rich areas. Considering local abiotic biotic factors is key for understanding fate dryland ecosystems under climate change increasing human pressure.

Язык: Английский

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Effects of plant diversity on soil carbon in diverse ecosystems: a global meta‐analysis

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Год журнала: 2019, Номер 95(1), С. 167 - 183

Опубликована: Окт. 18, 2019

ABSTRACT Soil organic carbon (SOC) is a valuable resource for mediating global climate change and securing food production. Despite an alarming rate of plant diversity loss, uncertainties concerning the effects on SOC remain, because not only stimulates litter inputs via increased productivity, thus enhancing SOC, but also microbial respiration, reducing SOC. By analysing 1001 paired observations mixtures corresponding monocultures from 121 publications, we show that both content stock are average 5 8% higher in species than monocultures. These positive mixture increase over time more pronounced deeper soils. Microbial biomass carbon, indicator release formation, increases, proportion lower mixtures. Moreover, these species‐mixture consistent across forest, grassland, cropland systems independent background climates. Our results indicate converting 50% forests to would 2.70 Pg C soil annually period 20 years: about 30% annual fossil‐fuel emissions. study highlights importance preservation maintenance sequestration discussions policy.

Язык: Английский

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