Tundra ecosystems are typically carbon (C) rich but nitrogen (N) limited. Since biological N2 fixation is the major source of biologically available N, the soil N2-fixing (i.e., diazotrophic) community serves as an essential N supplier to the tundra ecosystem. Recent climate warming has induced deeper permafrost thaw and adversely affected […]
Labile carbon (C) input to soil can accelerate or slow the decomposition of soil organic matter, a phenomenon called priming. However, priming is difficult to predict, making its relationship with C input elusive. To assess this relationship, we added 13C-glucose at five levels (8 to 1606 μg C g−1 week−1) to the soil from […]
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.
The cryosphere—the portion of the Earth’s surface where water is in solid form for at least one month of the year—has been shrinking in response to climate warming. The extents of sea ice, snow, and glaciers, for example, have been decreasing. In response, the ecosystems within the cryosphere and those […]
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 […]
The article focuses on the decommissioning of dams across the United States. Many dams were built after World War II to provide sources of hydraulic power. Now that these power suppliers make up little of the nation’s power resources, policy makers, conservationists, and environmentalists are opting to decommission the dams. […]
Isoprenoidal glycerol dialkyl glycerol tetra ethers (iGDGTs) are core membrane lipids of many archaea that enhance the integrity of cytoplasmic membranes in extreme environments. We examined the iGDGT profiles and corresponding aqueous geochemistry in 40 hot spring sediment and microbial mat samples from the U.S. Great Basin with temperatures ranging […]
High daily temperature range of soil (DTRsoil) negatively affects soil microbial biomass and activity, but its interaction with seasonal soil moisture in regulating ecosystem function remains unclear. For our 5-year field study in the Chihuahuan Desert, we suspended shade cloth 15 cm above the soil surface to reduce daytime temperature […]
Sunrise over the subtropical oak woodland, elevated CO2 experiment at the Kennedy Space Center, Florida. The experiment used open-top chambers to increase CO2 concentrations, with paired chambers with no extra CO2 serving as controls. The experiment ran from 1996-2007. Photo credit: Bert Drake.
The Carbon Copy is the Ecoss bi-monthly newsletter featuring news, publications, and comment from around the research center. Read past issues: February 2023 November 2022