Abstract The paradigm that permafrost-affected soils show restricted mineral nitrogen (N) cycling in favor of organic N compounds is based on the observation net mineralization rates these cold climates are negligible. However, we find here this perception wrong. By synthesizing published data plant-soil-microbe system permafrost ecosystems gross ammonification and nitrification active layers w...

Nitrification, the chemoautotrophic process by which NH4-N is converted to NO,-N, is an integral biogeochemical transformation in stream ecosystems. Previous research has shown that experimental addition of dissolved organic C inhibits rates of nitrification, and that NH4-N addition stimulates rates of nitrification. In many streams, large amounts of C and N may be present in particulate and so...

Turbic Cryosols (permafrost soils characterized by cryoturbation, i.e., by mixing of soil layers due to freezing and thawing) are widespread across the Arctic, and contain large amounts of poorly decomposed organic material buried in the subsoil. This cryoturbated organic matter exhibits retarded decomposition compared to organic material in the topsoil. Since soil organic matter (SOM) decompos...

Slow release of nitrate by charred organic matter used as a soil amendment (i.e. biochar) was recently suggested as potential mechanism of nutrient delivery to plants which may explain some agronomic benefits of biochar. So far, isolated soil-aged and composted biochar particles were shown to release considerable amounts of nitrate only in extended (>1 h) extractions ("slow release"). In this s...

Historically, terrestrial food web theory has been compartmentalized into interactions among aboveground or belowground communities. In this study we took a more synthetic approach to understanding food web interactions by simultaneously examining four trophic levels and investigating how nutrient (nitrogen and carbon) and detrital subsidies impact the ability of the belowground microbial commu...

The effect of the time of catch crop (field pea) incorporation [catch crop incorporated in the autumn (A) or in the spring (B) versus plots without a catch crop (C)] on the soil enzymes related to N transformation (urease - UR, protease - PRO, nitrate reductase - NR, arginine ammonification rate - AAR), the total N and mineral N as well as microbial biomass N (MBN) contents were investigated in...

Aim: There are few studies dealing with the biogeochemical processes occurring in small estuaries receiving high sewage loading in tropical regions. The aim of this investigation was to characterize the biogeochemical behavior of nutrients in superficial waters collected at the Iguaçu estuarine system, during specific conditions (neap tide), located at the inner sector of a heavily eutrophicate...

Monthly time-series data (1998–2009) of bottom water oxygen, nitrate and nitrite concentrations from the outer shelf (150m water depth) in the oxygen minimum zone offshore Peru were coupled to a layered biogeochemical sediment model to investigate benthic-pelagic coupling over multi-annual time scales. The model includes the mineralization of four reactive pools of particulate organic carbon (P...

Here we present the physiological features of Pseudomonas extremaustralis strain USBA-GBX-515 (CMPUJU 515), isolated from soils in Superparamo ecosystems, > 4000 m.a.s.l, in the northern Andes of South America, as well as the thorough analysis of the draft genome. Strain USBA-GBX-515 is a Gram-negative rod shaped bacterium of 1.0-3.0 μm × 0.5-1 μm, motile and unable to form spores, it grows aer...

Biomineralization is a universal phenomenon in the ocean that plays an important role marine geochemical circulation. The genus Alteromonas indigenous taxon with wide distribution and various ecological roles ocean, but biomineralization by this has not been reported. In study, five spp. were found to induce mineral crystal formation of different shapes sizes agar media. Further studies on deep...