Journal of Ecology & Sustainability

Soil Organic Carbon Depletion and Microbial Community Restructuring Under Chronic Nitrogen Deposition in Temperate Deciduous Forest Ecosystems: Evidence from a 12-Year Mesocosm Experiment

Casey Robinson — 2026-04-13

Chronic atmospheric nitrogen (N) deposition exerts profound yet heterogeneous effects on soil organic carbon (SOC) dynamics and belowground microbial assemblages in temperate deciduous forests. This study integrates 12 years of manipulative mesocosm data from a mixed Quercus–Fagus stand to quantify SOC mineralization rates, fungal-to-bacterial biomass ratios, and extracellular enzyme stoichiometry under simulated N loading gradients (0–60 kg N ha⁻¹ yr⁻¹). Phospholipid fatty acid (PLFA) profiling and metagenomic sequencing revealed a significant suppression of ectomycorrhizal fungal guilds and a concomitant shift toward copiotrophic bacterial dominance at deposition rates exceeding 30 kg N ha⁻¹ yr⁻¹. SOC stocks declined by 18.4% in high-N treatments, driven primarily by enhanced oxidative enzyme activity. These findings underscore critical thresholds for N-mediated destabilization of forest carbon sequestration and inform deposition-sensitive ecosystem management frameworks.

Biogeochemical Nitrogen Cycling Versus Phosphorus Stoichiometry in Temperate Wetland Restoration: A Comparative Evaluation of Nutrient-Driven Macrophyte Community Assembly Trajectories

Chris Jones — 2026-04-13

Wetland restoration strategies frequently diverge on whether nitrogen (N) or phosphorus (P) dynamics serve as the primary lever governing macrophyte community reassembly. This study conducted a paired-catchment comparative analysis across twelve restored temperate freshwater wetlands in Central Europe and East Asia, quantifying N:P stoichiometric ratios, denitrification potential, and phosphorus sorption capacity over a 36-month chronosequence. Redundancy analysis and structural equation modelling revealed that P-limitation thresholds exerted stronger directional control over late-successional macrophyte functional trait composition, whereas N-loading governed early colonisation rates. Sediment redox gradients acted as a confounding modifier of both nutrient pathways. These findings challenge the prevalent N-centric paradigm in eutrophication management and provide quantitative benchmarks for adaptive nutrient-targeting protocols in temperate wetland restoration planning.

Soil Carbon Sequestration Dynamics Under Differential Mycorrhizal Inoculation Regimes in Fragmented Temperate Deciduous Woodlands: A Microcosm-to-Landscape Scaling Analysis

Cameron King — 2026-04-13

Mycorrhizal fungal networks play a pivotal yet poorly quantified role in mediating soil organic carbon (SOC) stabilization within fragmented temperate deciduous woodlands. This study examined arbuscular and ectomycorrhizal inoculation gradients across experimentally isolated woodland patches in central Germany, combining phospholipid fatty acid (PLFA) profiling, stable isotope (δ¹³C) tracing, and landscape-scale LiDAR-derived canopy fragmentation indices. Results from 48 monitored microcosm plots, upscaled using spatially explicit carbon flux modelling, demonstrated that ectomycorrhizal dominance significantly enhanced recalcitrant SOC fractions (particulate organic matter; POM) by 23.4% relative to arbuscular-dominated plots. Edge-effect amplification under high landscape fragmentation reduced mycorrhizal hyphal network continuity by up to 38%, substantially diminishing SOC stabilization efficiency. These findings highlight the critical interdependence between woodland patch geometry, mycorrhizal community structure, and long-term carbon sink functionality.