Soil organic matter turnover: Global implications from δ13C and δ15N signatures

The Science of The Total Environment, Journal Year: 2023, Volume and Issue: 912, P. 169423 - 169423

Published: Dec. 20, 2023

Language: Английский

---

Reduced accrual of mineral-associated organic matter after two years of enhanced rock weathering in cropland soils, though no net losses of soil organic carbon

Biogeochemistry, Journal Year: 2024, Volume and Issue: 167(8), P. 989 - 1005

Published: July 23, 2024

Abstract Enhanced rock weathering (ERW), the application of crushed silicate to soil, can remove atmospheric carbon dioxide by converting it (bi) carbonate ions or solid minerals. However, few studies have empirically evaluated ERW in field settings. A critical question remains as whether additions might positively negatively affect soil organic matter (SOM)—Earth’s largest terrestrial (C) pool and a massive reservoir nitrogen (N). Here, three irrigated cropland trials California, USA, we investigated effect meta-basalt on different pools (i.e., mineral-associated matter, MAOM, particulate POM), active microbial biomass, community composition. After 2 years additions, MAOM stocks were lower upper surface (0–10 cm) plots with compared unamended control plots. At sites where baseline pre-treatment data available, neither total SOC nor SON decreased over study accrual rate MAOM-C MAOM-N at 0–10 cm was vs. controls. Before is deployed large scales, our results suggest that should assess effects SOM pools, especially multi-year time scales environmental contexts, accurately changes net C understand mechanisms driving interactions between cycling.

Language: Английский

---

Biogeochemistry of Riverine Organic Matter Inputs to the Patagonian Fjords and Implications for Fjord Organic Carbon Budgets

Journal of Geophysical Research Biogeosciences, Journal Year: 2025, Volume and Issue: 130(1)

Published: Jan. 1, 2025

Abstract Fjords are increasingly recognized as hotspots for organic carbon (OC) burial. The OC buried in fjords is of both marine and terrestrial origin, with a predominance worldwide. proportions traditionally calculated using end‐member modeling based on δ 13 C and/or N/C. However, characterizing the remains challenge, authors inconsistently measurements obtained land plants, soils, river sediments. Here, we analyzed TOC, C, N/C composition soil samples, suspended sediments, bulk grain‐size fractions sediments from main rivers discharging into Patagonian (44–48°S), to identify processes that affect biogeochemistry matter reaching via rivers. Radiocarbon indicate contain 0.18% petrogenic variable concentrations biospheric OC. Despite significantly decreasing precipitation, relatively stable around −27‰. In contrast, highly variable, mostly due high contribution nitrogen glacier‐fed Furthermore, varies sediment grain size, making it virtually impossible define fixed value represent end‐member. By comparison, size has limited influence C. Overall, our results support use riverine mixing models, regardless presence glaciers watershed, they suggest fraction fjord may have been underestimated.

Language: Английский

---

Afforestation and wildfire-induced grassland degradation: Impact on soil carbon dynamics in temperate grasslands, Drakensberg, South Africa

CATENA, Journal Year: 2025, Volume and Issue: 252, P. 108886 - 108886

Published: March 5, 2025

Language: Английский

---

Carbon dynamics and pathways in soil density fractions across different land-use types over 3000 years: Insights from 13C natural abundance

CATENA, Journal Year: 2025, Volume and Issue: 254, P. 108968 - 108968

Published: March 24, 2025

Language: Английский

---

Impacts of repeated forest fires and agriculture on soil organic matter and health in southern Amazonia

CATENA, Journal Year: 2025, Volume and Issue: 254, P. 108924 - 108924

Published: March 26, 2025

Language: Английский

---

Turnover of soil microaggregate‐protected carbon and the challenge of microscale analyses

Journal of Plant Nutrition and Soil Science, Journal Year: 2024, Volume and Issue: 187(1), P. 143 - 152

Published: Jan. 18, 2024

Abstract Background Microaggregates are suspected to protect soil organic carbon (SOC) from microbial decay, but its residence time is not well understood. Aims We aimed at unraveling the relevance of microaggregates for C storage and testing hypothesis that in interior aggregates older, compared exterior. Methods sampled under C3 vegetation a site where cropping shifted C4 36 years ago. isolated free macroaggregate‐occluded size fractions (250–53 µm) by wet sieving ultrasound, manually therefrom, analyzed whether vegetation‐related differences δ 13 could be traced exterior microaggregate cross‐sections using elemental laser ablation‐isotope ratio mass spectrometry. Results Size fraction weights comprised <5% microaggregates. Based on source partitioning approach including C3‐ C4‐derived C, we found mean times SOC occluded 62 105 years, respectively. Thus, was longer than (35 years) bulk (58 years). The small‐scale variability within aggregate considerable, both soil, yet without significant ( p = 0.46) between locations. Conclusions conclude do persist an intact form such long‐term systematic patterns parts can develop.

Language: Английский

---

Stable isotope analysis in soil prospection reveals the type of historic land-use under contemporary temperate forests in Europe

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: June 26, 2024

Abstract The determination of δ 13 C and 15 N values is a common method in archaeological isotope analysis—in studying botanical human remains, dietary practices, less typically soils (to understand methods agricultural cultivation, including fertilization). Stable measurements are also commonly used ecological studies to distinguish different ecosystems trace diachronic processes biogeochemical mechanisms, however, the application this geochemical prospection, for determining historic land-use impact, remains unexplored. study at hand focuses on deserted site Cistercian manor, dating from thirteenth fifteenth centuries. Isotopic anthropogenically influenced have been compared approximately 400 archaeobotanical, soil, sediment samples collected globally. results reveal potential soil impact past land use as identify specific types activities, distinguishing crop production or grazing. ratios likely reflect fertilization practices and—in case—the indicate presence cereal cultivation (C 3 cycle plants) that medieval manor was primarily grain rather than animal husbandry.

Language: Английский

---

Vegetation Types Can Affect Soil Organic Carbon and δ13C by Influencing Plant Inputs in Topsoil and Microbial Residue Carbon Composition in Subsoil

Sustainability, Journal Year: 2024, Volume and Issue: 16(11), P. 4538 - 4538

Published: May 27, 2024

Plantation is an economical and effective method of ecological restoration, which also a common means to increase soil organic carbon (SOC) content. However, the effects vegetation types on SOC accumulation δ13C distribution during restoration are still not clear. Therefore, we evaluated soils under four measures: plantation (PL, dominated by Olea europaea ‘Leccino’), grasslands [GLs, Setaria viridis], croplands [CLs, Zea mays] shrublands (SLs, Lycium chinense Mill), after 11-year restoration. natural stable isotope abundance in recovery modes were determined, while amino sugars (ASs) lignin phenols (LPs) used as biomarkers identify microbial- plant-derived carbon, respectively. The results showed that SOC, AS, LP decreased with increasing depth, same trend topsoil (0–20 cm). ASs subsoil (40–50 cm) significantly higher GLs than CLs PL, fungi residue was subsoil. mainly affected plant factors, especially litter. With effect plants decreased, microorganisms increased. Vegetation could affect influencing inputs topsoil. In subsoil, differences microbial compositions different enrichment. study revealed emphasized can input provided reference for development management policies areas.

Language: Английский

---

Carbon Balance in Soils under Conifers and Broadleaved Species within La Sierra, Dominican Republic

Published: July 15, 2024

Our research assesses the effects of four forest species, namely Swietenia macrophylla King, mahogany (L.) Jack., Pinus occidentalis Swartz, and caribaea Morelet var. Caribaea, on organic carbon (OC) dynamics dioxide equivalent balance (BCO2 Eq.) in soils beneath these species. Reforestation projects study region cover 1,200, 543, 770, 1,152 hectares, with respectively, being most relevant species reforestation within country. To determine BCO2 Eq. per unit area, we compared greenhouse gas (GHG) fluxes (CO2), methane (CH4), nitrous oxide (N2O) OC reserves found mineral soil to a depth 30 cm litter. For 18 months, conducted field measurements sixteen stands, for each results indicate that S. absorbed highest amount CO2, while released into atmosphere. from was -23.19 metric tons CO2 ha-1 year-1, P. occidentalis, mahogany, caribaea, corresponding quantities were -3.838, -2.299, +0.982, respectively. During measurement period, under macrophylla, net sinks Eq., behaved as source. The absorption rate atmosphere approximately 6, 10, 24 times higher when respective rates mahagony.

Language: Английский

---