Bacterial community dynamics were investigated in a land treatment unit (LTU) established at a site contaminated with highly weathered petroleum hydrocarbons in the C(10) to C(32) range. The treatment plot, 3,000 cubic yards of soil, was supplemented with nutrients and monitored weekly for total petroleum hydrocarbons (TPH), soil water content, nutrient levels, and aerobic heterotrophic bacteri...

Introduction: Soil heterotrophic respiration (Rh, an indicator of soil organic carbon decomposition) is an important carbon efflux of terrestrial ecosystems. However, the dynamics of soil Rh and its empirical relations with climatic factors have not been well understood. Methods: We incubated soils of three subtropical forests at five temperatures (10, 17, 24, 31, and 38 °C) and five moistures ...

Soil biological activity was calculated on a daily basis, using standard meteorological data from African weather stations, a simple soil water model, and commonly used assumptions regarding the relations between temperature, soil water content, and biological activity. The activity factor r(e_clim) is calculated from daily soil moisture and temperature, thereby taking the daily interaction bet...

To better understand how residue quality and seasonal conditions influence the flow of C from both root and straw residues into the soil microbial community, we followed the incorporation of C-labeled crimson clover (Trifolium incarnatum) and ryegrass (Lolium multiflorum) root and straw residues into the phospholipid fatty acids (PLFA) of soil microbial biomass. After residue incorporation unde...

Carbon sequestration in soil has emerged as a technology with significant potential to help stabilize atmospheric concentrations of greenhouse gases at non-threatening levels. Methods are thus needed to evaluate and recommend soil carbon sequestration practices based on their effects on carbon dynamics and environmental quality. There is scientific and practical consensus that simulation models...

Land use change (LUC) is the most dynamic force in terrestrial carbon stock change, and it is imperative to account for the dynamics of LUC in carbon stock change when forming land use policies. This paper explored the impacts of LUCs on carbon (C) stocks at a county scale and detected changes of soil C stocks within a county-scale land use planning policy. The LUCs within 1979–2006 in Fuyang C...

Examining the responses of root standing crop (biomass and necromass) and chemistry to soil warming is crucial for understanding root dynamics and functioning in the face of global climate change. We assessed the standing crop, total nitrogen (N) and carbon (C) compounds in tree roots and soil net N mineralization over the growing season after 6 years of experimental soil warming in a temperate...

Climate change factors such as elevated atmospheric carbon dioxide (CO₂) and ozone (O₃) can exert significant impacts on soil microbes and the ecosystem level processes they mediate. However, the underlying mechanisms by which soil microbes respond to these environmental changes remain poorly understood. The prevailing hypothesis, which states that CO₂- or O₃-induced changes in carbon (C) avail...

Afforestation of former croplands has been proposed as a promising way to mitigate rising atmospheric CO2 concentration in view of the commitment to the Kyoto Protocol. Central to this C sequestration is the dynamics of soil organic C (SOC) storage and stability with the development of afforested plantations. Our previous study showed that SOC storage was not changed after afforestation except ...

Regulatory mechanisms of soil respiratory carbon (C) release induced by substrates (i.e., plant derived substrates) are critical for predicting ecosystem responses to climate change, but the mechanisms are not well understood. In this study, we sampled soils from a long-term field manipulative experiment and conducted a laboratory incubation to explore the role of substrate supply in regulating...