Understanding impacts of drought on tree growth and forest health is of major concern given projected climate change. Droughts may become more common in the Southwest due to extreme temperatures that will drive increased evapotranspiration and lower soil moisture, in combination with uncertain precipitation changes. Utilizing ~1.3 million tree-ring widths […]
Both geomorphic setting and dynamic environmental variables influence riverine wetland vegetation distributions. Most studies of species distributions in riverine systems emphasize either hydrological variability or geomorphic controls, but rarely consider the interaction between the two. It is unknown whether and to what extent the relationship between the geomorphic template and […]
The Arctic continues to warm at a rate that is currently twice as fast as the global average (see essay on Surface Air Temperature). Warming is causing normally frozen ground (permafrost) to thaw, exposing significant quantities of organic soil carbon to decomposition by soil microbes (Romanovsky et al. 2010, Romanovsky […]
Optimality theory states that whole-tree carbon gain is maximized when leaf N and photosynthetic capacity profiles are distributed along vertical light gradients such that the marginal gain of nitrogen investment is identical among leaves. However, observed photosynthetic N gradients in trees do not follow this prediction, and the causes for […]
Giant Sequoia trees can be thousands of years old, are the most massive organisms on Earth, and reach astounding heights. But they can’t just keep on getting taller indefinitely, it seems. There are limits. Figuring out these limits and how they shape these giant forests is a main focus of Professor George Koch’s research, […]
Water plus soil makes mud, right? It’s definitely mud when it’s on the kitchen table at home. But for the Center for Ecosystem Science and Society (Ecoss), water plus soil makes paint, and it enjoyed centerpiece status on our table in Science in the Park in Flagstaff, last weekend, part […]
Plants can grow faster as atmospheric CO2 concentrations increase, but only if they have enough nitrogen or partner with fungi that help them get it, according to new research published this week in Science. The study was lead by César Terrer Moreno, a PhD student at Imperial College London, and […]
This story in the Washington Post (June 3, 2016) provides details on a major and surprising new report from the U.S. Geological Survey. The document raises questions about what will be the true carbon consequences of Alaska’s ongoing warming. Ted Schuur, permafrost researcher at Ecoss says about the new study “It’s important to remember […]
The future carbon balance of high-latitude ecosystems is dependent on the sensitivity of biological processes (photosynthesis and respiration) to the physical changes occurring with permafrost thaw. Predicting C exchange in these ecosystems is difficult because the thawing of permafrost is a heterogeneous process that creates a complex landscape. We measured […]
Soil organic matter (SOM) is heterogeneous in structure and has been considered to consist of various pools with different intrinsic turnover rates. Although those pools have been conceptually expressed in models and analyzed according to soil physical and chemical properties, separation of SOM into component pools is still challenging. In […]