In stratified lakes, a large portion of phytoplankton biomass is found—not at the surface, where sampling is easiest—but somewhere down the water column, in what is known as a subsurface chlorophyll maximum (SSCM). Researchers in Global Lake Ecological Observatory Network (GLEON) compared automated high-frequency chlorophyll fluorescence (ChlF) profiles with surface samples and discrete depth profiles. In 7 of the 11 lakes studied, automated sampling captured the presence of SSCM’s that would have been missed by conventional sampling.
How-and when-do ecosystems change character? Are those shifts reversible? And what signs might precede them? Such questions are hard enough to answer in a single place. One might think that incorporating different kinds of ecosystems would only complicate the problem. But a group of scientists in the Long-Term Ecological Research Network is finding a remarkably consistent pattern by combining models and data across several long-term ecological experiments.
Landscape ecologists and nature-lovers are well aware of the way that valleys collect deeper, moister soils than neighboring hill slopes and crests. Now, researchers at Coweeta LTER have have found that cool air, sliding downslope from higher elevations and pooling in mountain valleys, subsidizes productivity in a different way. The cold air drainage was most prevalent at night and in the evenings, so it had little effect on photosynthesis, but reduced plant and soil respiration by about 8 percent. Overall, the authors estimate it boosted annual net carbon uptake by about 15 percent.
PhysFest participants measure gas exchange on an annually-burned watershed. On June 5th, 45 plant eco-physiologists traveled to Kansas from all corners of the country to take part in the inaugural PhysFest. This “un-meeting,” held at the Konza Prairie Biological Station and LTER Site and hosted by the Kansas State Plant EcoPhys Lab, aimed to break all… Read more »
Early this year the annual Long Term Ecological Research (LTER) Mini-Symposium scheduled for Thursday, March 5, 2015, had to be postponed when inclement weather forced the closure of the National Science Foundation (NSF) (see http://bit.ly/1NkuT9Q). At the time we reported that webcasts of the talks would be presented in blocks of two or three at… Read more »