Shifting Mountain Tree Line Increases Soil Organic Carbon Stability Regardless of Land Use.

Climate and land use changes are causing trees line to shift up into mountain meadows. The effect of this vegetation change on the partitioning of soil carbon (C) between the labile particulate organic matter (POM-C) and stable mineral-associated organic matter (MAOM-C) pools is poorly understood. Therefore, we assessed these C pools in a 10 cm topsoil layer along forest-meadow ecotones with different land uses (reserve and pasture) in the Northwest Caucasus of Russia using the size fractionation technique (POM 0.

Contribution of microbial activity and vegetation cover to the spatial distribution of soil respiration in mountains.

The patterns of change in bioclimatic conditions determine the vegetation cover and soil properties along the altitudinal gradient. Together, these factors control the spatial variability of soil respiration () in mountainous areas. The underlying mechanisms, which are poorly understood, shape the resulting surface CO flux in these ecosystems.

Straw amendment and nitrification inhibitor controlling N losses and immobilization in a soil cooling-warming experiment.

It is common practice in agriculture to apply high‑carbon amendments, e.g. straw, or nitrification inhibitors (NI) to reduce soil nitrogen (N) losses.

Temperature Sensitivity of Topsoil Organic Matter Decomposition Does Not Depend on Vegetation Types in Mountains.

Rising air temperatures caused by global warming affects microbial decomposition rate of soil organic matter (SOM). The temperature sensitivity of SOM decomposition (Q) may depend on SOM quality determined by vegetation type. In this study, we selected a long transect (3.

Response of bacterial and fungal communities to high petroleum pollution in different soils.

Petroleum pollution of soils is a major environmental problem. Soil microorganisms can decompose a significant fraction of petroleum hydrocarbons in soil at low concentrations (1-5%). This characteristic can be used for soil remediation after oil pollution.

Impact of forest cover and conservation agriculture on sediment export: A case study in a montane reserve, south-western China.

Reforestation and agricultural conservation have long been recognized as important in reducing on-site soil loss and off-site sediment export. Quantitative assessment of their effectiveness is critical, and assists cost-benefit analysis and decision-making in land management and landscape planning. We applied a paired watershed approach to monitor 1-year sediment export in two watersheds with forest-dominated (reference) and mosaic (target) land use in the Naban River Watershed National Natural Reserve (NRWNNR) in Xishuangbanna, south-western China.

Nitrogen availability regulates topsoil carbon dynamics after permafrost thaw by altering microbial metabolic efficiency.

Input of labile carbon may accelerate the decomposition of existing soil organic matter (priming effect), with the priming intensity depending on changes in soil nitrogen availability after permafrost thaw. However, experimental evidence for the linkage between the priming effect and post-thaw nitrogen availability is unavailable. Here we test the hypothesis that elevated nitrogen availability after permafrost collapse inhibits the priming effect by increasing microbial metabolic efficiency based on a combination of thermokarst-induced natural nitrogen gradient and nitrogen addition experiment.

Temperature sensitivity and enzymatic mechanisms of soil organic matter decomposition along an altitudinal gradient on Mount Kilimanjaro.

Short-term acceleration of soil organic matter decomposition by increasing temperature conflicts with the thermal adaptation observed in long-term studies. Here we used the altitudinal gradient on Mt. Kilimanjaro to demonstrate the mechanisms of thermal adaptation of extra- and intracellular enzymes that hydrolyze cellulose, chitin and phytate and oxidize monomers ((14)C-glucose) in warm- and cold-climate soils.

Microbial growth and carbon use efficiency in the rhizosphere and root-free soil.

Plant-microbial interactions alter C and N balance in the rhizosphere and affect the microbial carbon use efficiency (CUE)-the fundamental characteristic of microbial metabolism. Estimation of CUE in microbial hotspots with high dynamics of activity and changes of microbial physiological state from dormancy to activity is a challenge in soil microbiology. We analyzed respiratory activity, microbial DNA content and CUE by manipulation the C and nutrients availability in the soil under Beta vulgaris.

Soil C and N availability determine the priming effect: microbial N mining and stoichiometric decomposition theories.

The increasing input of anthropogenically derived nitrogen (N) to ecosystems raises a crucial question: how does available N modify the decomposer community and thus affects the mineralization of soil organic matter (SOM). Moreover, N input modifies the priming effect (PE), that is, the effect of fresh organics on the microbial decomposition of SOM. We studied the interactive effects of C and N on SOM mineralization (by natural (13) C labelling adding C4 -sucrose or C4 -maize straw to C3 -soil) in relation to microbial growth kinetics and to the activities of five hydrolytic enzymes.

Stimulation of r- vs. K-selected microorganisms by elevated atmospheric CO(2) depends on soil aggregate size.

Increased root exudation under elevated atmospheric CO(2) and the contrasting environments in soil macro- and microaggregates could affect microbial growth strategies. We investigated the effect of elevated CO(2) on the contribution of fast- (r-strategists) and slow-growing (K-strategists) microorganisms in soil macro- and microaggregates. We fractionated the bulk soil from the ambient and elevated (for 5 years) CO(2) treatments of FACE-Hohenheim (Stuttgart) into large macro- (>2 mm), small macro- (0.