Some more of David Manning's PhD research just came out in Ecological Applications. The paper describes links between leaf litter stoichiometry and breakdown rate under ambient and nutrient-enriched conditions in our five study streams at Coweeta Hydrologic Laboratory. David's findings include homogenization of detrital stoichiometry across litter types under nutrient enrichment, as well as tight predictive relationships between litter stoichiometry and breakdown rates that may be useful for monitoring and management. Check it out here.
Last night Dan Nelson and Jon Benstead started the 15N additions in the four streams along our landscape temperature gradient in Iceland. So for the next five days each stream will have TWO drippers going - one adding phosphorus and one adding 15N-enriched nitrogen at tracer levels. Lots of work ahead of us as we follow where all the isotope goes and find out whether adding phosphorus has an effect on nitrogen uptake and routing through the food web. Below is a shot of Stream 11 (our coldest stream), with the phosphorus dripper on the right and metering pump delivering the isotope on the left.
Our streamside channel experiment is up and running in Iceland. This year we're crossing the temperature treatments with varying levels of phosphorus enrichment. We have some hypotheses about what might happen, but no clue what we'll actually see. That's what science is all about, right? Below are some shots of the channels and phosphorus drippers in action.
Congratulations to lab member Dr. Dan Nelson, who defended his dissertation last week. Dan did all the macroinvertebrate community and food web work for our whole-stream warming manipulation in Iceland. His papers will be rolling out very soon. Well done, Dan!
Early May saw Jon, Wyatt Cross, Alex Huryn, Philip Johnson and Jim Hood in Iceland to start the 2016 fieldwork. The first order of business for Wyatt and Jon was to start the phosphorus drippers in our four focal streams. As you can see below, there was still plenty of snow around, so we were setting up inside snow caves in two of the streams.
The rest of the time was spent setting up the streamside channel experiment (now in its third iteration), during which we were joined by Jim's new student, Lyndsie Collis. Predictably, it ended up being a ton of work with plenty of curve balls sprinkled throughout the whole process. Finally, the day after Alex and Jon left, Lyndsie and Jim got the experiment going. It's interesting to compare the set-up with the picture below from 2013. The temperature array is now twice the size and includes a dripper in each of the thirty channels, which contain a total of 3000 tiles. It's a beast.
Check out the new video podcast about our research project in Iceland. The podcast was funded by our NSF award and put together by our film team, Hans Glasmann (an MFA student in the Montana State University Science and Natural History Filmmaking Program) and Dennis Aig, the director of the School of Film and Photography at Montana State University.
Tanner Williamson's MS research just came out in Global Change Biology. The paper contains some very interesting data from our temperature manipulations in the stream-side channels up at Hengill. Check it out here.
The summer is finally here and Jon and Wyatt have arrived in Iceland to start the phosphorus additions to our four study streams up at Hengill. Tomorrow we'll see just how much snow is up at the field site. Hopefully, not TOO much, as lots of the white stuff can really slow things down. Watch this space.