Understanding the response of permafrost microbial communities to climate warming is crucial for evaluating ecosystem feedbacks to global change. This study investigated soil bacterial and archaeal communities by Illumina MiSeq sequencing of 16S rRNA gene amplicons across a permafrost thaw gradient at different depths in Alaska with thaw progression for […]
The linkages between fluvial geomorphology and aquatic ecosystems are commonly conceptualized as a one-way causal chain inwhich geomorphic processes create the physical template for ecological dynamics. In streams with a travertine step-pool morphology, however, biotic processes strongly influence the formation and growth of travertinedams, creating the potential fornumerous feedbacks.Herewetakeadvantage of […]
Evapotranspiration (ET) comprises a major portion of the water budget in forests, yet few studies have measured or estimated ET in semi-arid, high-elevation ponderosa pine forests of the south-western USA or have investigated the capacity of models to predict ET in disturbed forests. We measured actual ET with the eddy […]
Rising temperatures are expected to reduce global soil carbon (C) stocks, driving a positive feedback to climate change1, 2, 3. However, the mechanisms underlying this prediction are not well understood, including how temperature affects microbial enzyme kinetics, growth efficiency (MGE), and turnover4, 5. Here, in a laboratory study, we show […]
Rising atmospheric CO2 concentrations may alter the nitrogen (N) content of ecosystems by changing N inputs and N losses, but responses vary in field experiments, possibly because multiple mechanisms are at play. We measured N fixation and N losses in a subtropical oak woodland exposed to 11 years of elevated […]
Bacteria grow and transform elements at different rates, and as yet, quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to stable isotope probing (SIP) that enables […]
Old soil carbon (C) respired to the atmosphere as a result of permafrost thaw has the potential to become a large positive feedback to climate change. As permafrost thaws, quantifying old soil contributions to ecosystem respiration (Reco) and understanding how these contributions change with warming is necessary to estimate the […]
On January 5th, Bruce Hungate presented at Science on Tap at the Green Room, Flagstaff. Featuring an update on the Paris agreement (COP21), new science, legal intrigue, and what Elvis can teach us about climate models.
Overview Using a technique called data-assimilation, we can inform existing ecosystem models with measurements from field experiments. In combination with meta-analysis, this approach becomes a powerful statistical tool to improve our predictions of ecosystem responses to global change. We recently used data-assimilation to study the effect of warming and CO2 enrichment on […]
Overview Most global change research focuses on individual components, but the environment is changing in multiple ways simultaneously. The Jasper Ridge Global Change Experiment seeks to find out how these combined changes will affect ecosystems. Researchers tested the response of a California grassland to: climate change elevated atmospheric carbon dioxide […]