This paper advances our understanding of forest responses to elevated CO2 by considering implications for nutrient availability across the soil profile and the particular role of nutrient recycling in the rhizosphere versus soil organic matter mineralization.

Application for BG Letter format accepted.

Yedema et al. used multiple biomarkers and palynological proxies to track the fate of plant-derived, soil-microibal, fluvial, and marine-produced organic matter in the coastal sediments of the northern Gulf of Mexico. The key findings show plant-derived materials reaching the deepest waters in contrast to fluvial organic matter confined to the proximity of the river mouth. This source-specific difference in the coastal distribution and storage of organic matter can greatly contribute to elucidating the role of terrestrial organic matter in coastal carbon sequestration.

This laboratory and protein database research by Fabisik and co-workers demonstrates that the widespread freshwater cyanobacterium Microcystis aeruginosa is capable of producing nitrous oxide, a very potent greenhouse gas, from nitrite. This discovery poses the important question about the relevance of these organisms for global nitrous oxide emissions into the atmosphere and their response to environmental change.