Stocks of soil organic carbon represent a large component of the carbon cycle that may participate in climate change feedbacks, particularly on decadal and centennial timescales. For Earth system models (ESMs), the ability to accurately represent the global distribution of existing soil carbon stocks is a prerequisite for accurately predicting […]
Humans are altering the environment in many ways. While local environmental damage (landfills, oil spills, urban smog) is still prevalent, we now also realize that human activities are altering the Earth System as a whole, that our environmental crisis has become truly global.
This paper discusses the disturbances within and between ecosystems that result in element redistribution involving element transport in the biosphere, hydrosphere, lithosphere and atmosphere. It also discusses the disturbances (e.g. floods/landslides and vulcanism/dust storms) that redistribute and mobilize element in ratios that frequently differ from ecosystem stoichiometries, influence biogeochemical interactions […]
Methane consumption by temperate forest soils is a major sink for this important greenhouse gas, but little is known about how tree species influence CH4 uptake by soils. Here, we show that six common tree species in Siberian boreal and temperate forests significantly affect potential CH4 consumption in laboratory microcosms. […]
The labeled atoms of carbon and nitrogen are widely used in biology, biochemistry, and soil science. Both radioactive (14C) and stable (12C, 13C,15N) isotopes are used as such labels. Recently, an increase in mass spec-trometry sensitivity made it possible to study natural ratios of carbon (13C/12C) and nitrogen (15N/14N) stableisotopes […]
Increased carbon storage in ecosystems due to elevated CO2 may help stabilize atmospheric CO2 concentrations and slow global warming. Many field studies have found that elevated CO2 leads to higher carbon assimilation by plants, and others suggest that this can lead to higher carbon storage in soils, the largest and […]
1. Ecological restoration often involves returning ecosystem structure to some predisturbance reference state, but ecosystem function must also recover if restoration efforts are to be self-sustaining over the long term. In the south-western United States, ponderosa pine forest structure was altered by disruption of the fire regime following Euro-American settlement. […]
Foliar chemistry influences leaf decomposition, but little is known about how litter chemistry affects the assemblage of bacterial communities during decomposition. Here we examined relationships between initial litter chemistry and the composition of the bacterial community in a stream ecosystem. We incubated replicated genotypes of Populus fremontii and P. angustifolia leaf litter that differ […]
Background Forests can sequester carbon dioxide, thereby reducing atmospheric concentrations and slowing global warming. In the U.S., forest carbon stocks have increased as a result of regrowth following land abandonment and in-growth due to fire suppression, and they currently sequester approximately 10% of annual US emissions. This ecosystem service is […]
One difficulty in using bioremediation at a contaminated site is demonstrating that biodegradation is actually occurring in situ. The stable isotope composition of contaminants may help with this, since they can serve as an indicator of biological activity. To use this approach it is necessary to establish how a particular […]