Soil-organic matter (SOM) is a complex array of components including soil fauna and flora at different stages of decomposition (Berg et al . , 1982). I ts concentration in soils can vary from 0.5% in mineral soils to almost 100% in peat soils (Brady, 1974). Organic matter (OM) in the surface mineral soil is considered a major determinant of forest ecosystem productivity because it affects water...

Microbially-derived carbon inputs to soils play an important role in forming soil organic matter (SOM), but detailed knowledge of basic mechanisms of carbon (C) cycling, such as stabilization of organic C compounds originating from rhizodeposition, is scarce. This study aimed to investigate the stability of rhizosphere-produced carbon components in a model laboratory mesocosm of Pinus resinosa ...

Soil organic matter (SOM) and the carbon and nutrients therein drive fundamental submicron- to global-scale biogeochemical processes and influence carbon-climate feedbacks. Consensus is emerging that microbial materials are an important constituent of stable SOM, and new conceptual and quantitative SOM models are rapidly incorporating this view. However, direct evidence demonstrating that micro...

A common finding in multiple CO(2) enrichment experiments in forests is the lack of soil carbon (C) accumulation owing to microbial priming of 'old' soil organic matter (SOM). However, soil C losses may also result from the accelerated turnover of 'young' microbial tissues that are rich in nitrogen (N) relative to bulk SOM. We measured root-induced changes in soil C dynamics in a pine forest ex...

Boone, 1994). Despite these efforts, no single fractionation method has been shown to cleanly distinguish Nitrogen mineralization in irrigated lowland rice (Oryza sativa L.) SOM fractions based on their contributions to soil N soils is poorly predicted by total soil C and N. To improve its prediction, two humic acid fractions were extracted with NaOH from lowland mineralization across a wide ra...

Bio-electrical responses obtained from freshwater sediments by employing microbial fuel cell (MFC) technology were investigated in this experimental study. During the electricity generation, organic matter in the sediment was microbially oxidized under anaerobic conditions with an electrode serving as a terminal electron acceptor. It was found that the sediment organic matter (SOM) associated w...

in this study, the role of soil properties in making difference between plant communitieswas examined. first, four plant types were identified, including pteropyrumaucheri-salsolarigida، astragalus gossypinus - acanthophyllum herateens، amygdalus scoparia – achilla millefolium and ephedra intermedia – erigon capestra, through randomized systematic sampling and field survey in representative are...

One of the main factors of water erosion is the natural characteristics of the soil called "erodibility" or"detachability". The present study aims to analyze the variations of soil erodibility factor in different plains and thefactors related to it. Erodibility is one the key factors in some models of erosion and sediment such as Universal SoilLoss Equation (USLE), Revised USLE (RUSLE), and Mod...

The effects of atmospheric nitrogen (N) deposition on organic matter decomposition vary with the biochemical characteristics of plant litter. At the ecosystem-scale, net effects are difficult to predict because various soil organic matter (SOM) fractions may respond differentially. We investigated the relationship between SOM chemistry and microbial activity in three northern deciduous forest e...

The impact of rising atmospheric carbon dioxide (CO2) may be mitigated, in part, by enhanced rates of net primary production and greater C storage in plant biomass and soil organic matter (SOM). However, C sequestration in forest soils may be offset by other environmental changes such as increasing tropospheric ozone (O3) or vary based on species-specific growth responses to elevated CO2. To un...