High latitude warming and permafrost thaw will expose vast stores of deep soil organic carbon (SOC) to decomposition. Thaw also changes water movement causing either wetter or drier soil. The fate of deep SOC under different thaw and moisture conditions is unclear. We measured weekly growing-season δ13C of ecosystem respiration […]
A mini-symposium and short training course on ‘New Advances in Land Carbon Cycle Modeling’ was held May 20-26, 2018 at Northern Arizona University in Flagstaff, USA. The mini-symposium and short training course were organized by ECOSS professor Yiqi Luo and Research Associate Lifen Jiang and focused on new theory on […]
Many Low Arctic tundra regions are currently undergoing a vegetation shift towards increasing growth and groundcover of tall deciduous shrubs due to recent climate warming. Vegetation change directly affects ecosystem carbon balance, but it can also affect soil biogeochemical cycling through physical and biological feedback mechanisms. Recent studies indicate that […]
Paleo-redox proxies are crucial for reconstructing past bottom water oxygen concentration changes brought about by ocean circulation and marine productivity shifts in response to climate forcing. Carbonate I/Ca ratios of multiple benthic foraminifera species from Ocean Drilling Program Hole 1017E—a core drilled within the Californian oxygen minimum zone (OMZ), on […]
Permafrost is a distinct feature of the terrestrial Arctic and is vulnerable to climate warming. Permafrost degrades in different ways, including deepening of a seasonally unfrozen surface and localized but rapid development of deep thaw features. Pleistocene ice-rich permafrost with syngenetic ice-wedges, termed Yedoma deposits, are widespread in Siberia, Alaska, […]
How healthy will Earth’s ecosystems be in 2027, 2067 and beyond? It’s an important question to ask, especially on World Environment Day, June 5. To find answers, scientists affiliated with the National Science Foundation’s (NSF) Long-Term Ecological Research (LTER) network came together this spring at an NSF LTER mini-symposium. “Arctic […]
Temperature rise in the Arctic is causing deepening of active layers and resulting in the mobilization of deep permafrost dissolved organic matter (DOM). However, the mechanisms of DOM mobilization from Arctic soils, especially upper soil horizons which are drained most frequently through a year, are poorly understood. Here we conducted […]
Ecosystems acquire nitrogen from the atmosphere, but this source can’t account for the large nitrogen capital of some systems. The finding that bedrock can also act as a nitrogen source may help solve the riddle.
Recent observations suggest that permafrost thaw may create two completely different soil environments: aerobic in relatively well-drained uplands and anaerobic in poorly drained wetlands. The soil oxygen availability will dictate the rate of permafrost carbon release as carbon dioxide (CO2) and as methane (CH4), and the overall effects of these […]
Elevated carbon dioxide (CO2) caused greater accumulation of carbon (C) and nutrients in both vegetation and O horizons over a 5-yr sampling period in a scrub oak ecosystem in Florida. Elevated CO2 had no effect on any measured soil property except extractable phosphorus (P), which was lower with elevated CO2 […]