Elevated CO2 is expected to lower plant nutrient concentrations via carbohydrate dilution and increased nutrient use efficiency. Elevated CO2 consistently lowers plant foliar nitrogen, but there is no consensus on CO2 effects across the range of plant nutrients. We used meta-analysis to quantify elevated CO2 effects on leaf, stem, root, […]
Plant growth often responds rapidly to experimentally simulated climate change1, 2. Feedbacks can modulate the initial responses3, but these feedbacks are difficult to detect when they operate on long timescales4. We transplanted intact plant–soil mesocosms down an elevation gradient to expose them to a warmer climate and used collectors and […]
Evidence is mounting that extinctions are altering key processes important to the productivity and sustainability of Earth’s ecosystems1, 2, 3, 4. Further species loss will accelerate change in ecosystem processes5, 6, 7, 8, but it is unclear how these effects compare to the direct effects of other forms of environmental […]
Global environmental changes are expected to alter ecosystem carbon and nitrogen cycling, but the interactive effects of multiple simultaneous environmental changes are poorly understood. Effects of these changes on the production of nitrous oxide (N2O), an important greenhouse gas, could accelerate climate change. We assessed the responses of soil N2O […]
Carbon uptake by forests is a major sink in the global carbon cycle, helping buffer the rising concentration of CO2 in the atmosphere, yet the potential for future carbon uptake by forests is uncertain. Climate warming and drought can reduce forest carbon uptake by reducing photosynthesis, increasing respiration, and by […]
The Rehai and Ruidian geothermal fields, located in Tengchong County, Yunnan Province, China, host a variety of geochemically distinct hot springs. In this study, we report a comprehensive, cultivation-independent census of microbial communities in 37 samples collected from these geothermal fields, encompassing sites ranging in temperature from 55.1 to 93.6°C, […]
Male circumcision reduces female-to-male HIV transmission. Hypothesized mechanisms for this protective effect include decreased HIV target cell recruitment and activation due to changes in the penis microbiome. We compared the coronal sulcus microbiota of men from a group of uncircumcised controls (n = 77) and from a circumcised intervention group […]
Branched glycerol dialkyl glycerol tetraethers (bGDGTs) are membrane-spanning lipids that likely stabilize membranes of some bacteria. Although bGDGTs have been reported previously in certain geothermal environments, it has been suggested that they may derive from surrounding soils since bGDGTs are known to be produced by soil bacteria. To test the […]
At 6 A.M. on the first day of winter break, a van full of high school stu- dents and teachers set out for Fossil Creek in Arizona to conduct measurements for an ongoing environmental project (which monitors changes to the creek). The group had a long day ahead—hiking about 7 […]
Travertine deposits of calcium carbonate can dominate channel geomorphology in streams where travertine deposition creates a distinct morphology characterized by travertine terraces, steep waterfalls, and large pools. Algae and microorganisms can facilitate travertine deposition, but how travertine affects material and energy flow in stream ecosystems is less well understood. Nearly […]