Background It is now apparent that the complex microbial communities found on and in the human body vary across individuals. What has largely been missing from previous studies is an understanding of how these communities vary over time within individuals. To the extent to which it has been considered, it […]
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 […]
We present an approach to estimate the feedback from large-scale thawing of permafrost soils using a simplified, data-constrained model that combines three elements: soil carbon (C) maps and profiles to identify the distribution and type of C in permafrost soils; incubation experiments to quantify the rates of C lost after […]
Fossil Creek Restoration Can we restore a river after a century of disturbance? Research in the Marks Lab has addressed the following questions: How did native species respond to restoration? Employing a BACI design (Before After Control Impact), we determined the relative importance of flow restoration versus non-native fish removal […]
Ecoss studies the interactions of plants with their physical and biotic environments at a fundamental level common to all organisms: gas exchange, energy balance, and water relations. We explore how plants make a living in diverse environments ranging from deserts to rainforests. A longstanding interest is the biophysical and ecological […]