Soil microbial organisms are central to carbon (C) and nitrogen (N) transformations in soils, yet not much is known about the stable isotope composition of these essential regulators of element cycles. We investigated the relationship between C and N availability and stable C and N isotope composition of soil microbial […]
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 […]
Despite increasing interest in the effects of climate change on soil processes, the response of nitrification to elevated CO2remains unclear. Responses may depend on soil nitrogen (N) status, and inferences may vary depending on the methodological approach used. We investigated the interactive effects of elevated CO2 and inorganic N supply […]
Disturbances alter ecosystem carbon dynamics, often by reducing carbon uptake and stocks. We compared the impact of two types of disturbances that represent the most likely future conditions of currently dense ponderosa pine forests of the southwestern United States: (1) high-intensity fire and (2) thinning, designed to reduce fire intensity. […]
Understanding how elevated atmospheric CO2 alters the formation and decomposition of soil organic carbon (SOC) is important but challenging. If elevated CO2 induces even small changes in rates of formation or decay of SOC, there could be substantial feedbacks on the atmosphere’s concentration of CO2. However, the long turnover times […]
[1] The future size of the terrestrial methane (CH4) sink of upland soils remains uncertain, along with potential feedbacks to global warming. Much of the uncertainty lies in our lack of knowledge about potential interactive effects of multiple simultaneous global environmental changes. Field CH4 fluxes and laboratory soil CH4 consumption were […]
Forestry – including afforestation (the planting of trees on land where they have not recently existed), reforestation, avoided deforestation, and forest management – can lead to increased sequestration of atmospheric carbon dioxide and has therefore been proposed as a strategy to mitigate climate change. However, forestry also influences land-surface properties, […]
We determined the response of terrestrial methane (CH4) uptake to 4 years of full-factorial manipulations of precipitation and temperature in four ecosystems along a 50 km warm and dry to cold and wet climatic gradient (desert grassland, pinyon-juniper woodland, ponderosa pine forest, and mixed conifer forest). Our goals were to determine whether […]
In order to study controls on metabolic processes in soils, we determined the dynamics of 13CO2 production from two position-specific 13C-labeled pyruvate isotopologues in the presence and absence of glucose, succinate, pine, and legume leaf litter, and under anaerobic conditions. We also compared 13CO2 production in soils along a semiarid […]
Global mean temperature is predicted to increase by 2–7 °C and precipitation to change across the globe by the end of this century. To quantify climate effects on ecosystem processes, a number of climate change experiments have been established around the world in various ecosystems. Despite these efforts, general responses of […]