【元素循环】Jonathan Cole. Freshwater in flux. Nature Geoscience 2013 6: 13–14
Abstract
A surprising fraction of Earth's element cycling takes place in inland waters. Jonathan Cole suggests that interactions between these water bodies and the terrestrial biosphere are more extensive and interesting than previously thought.
【大气中的氧气】James Kasting. The mystery of atmospheric oxygen. Nature Geoscience 2013 6: 9–10
Abstract
Readily available O2 is vital to life as we know it. James Kasting looks at how and when the first whiffs of oxygen began to reach the Earth's atmosphere.
【北极土壤CO2排放】Rose M. Cory Byron C. Crump Jason A. Dobkowski and George W. Kling. Surface exposure to sunlight stimulates CO2release from permafrost soil carbon in the Arctic. PNAS
Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost allowing for microbial respiration of previously frozen C. Furthermore soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to surface waters. Once exposed the fate of this C is unknown but will depend on its reactivity to sunlight and microbial attack and the light available at the surface. In this study we manipulated water released from areas of thermokarst activity to show that newly exposed DOC is >40% more susceptible to microbial conversion to CO2 when exposed to UV light than when kept dark. When integrated over the water column of receiving rivers this susceptibility translates to the light-stimulated bacterial activity being on average from 11% to 40% of the total areal activity in turbid versus DOC-colored rivers respectively. The range of DOC lability to microbes seems to de