A bunch of new publications have appeared this year (the eventual products of past rejection woes...). One was Jim Hood's GCB paper that presents the ecosystem metabolism and nutrient uptake data from the pre-warming year and the first year of warming from our whole-stream temperature manipulation in Iceland. As the before-after pictures above show, some of the results were quite dramatic (that's the green alga Ulva, which went nuts in the summer after we began warming by less than 4 degrees C). Post-warming shifts in community structure were also associated with a dramatic increase in the nutrient use efficiency of the primary producers in the stream. These sorts of interactions between temperature and nutrient cycling are exactly what our research program in Iceland was designed to uncover. Good stuff.
Another notable recent publication from the lab is Mick Demi's Ecology paper that describes the responses of five macroinvertebrate communities to experimental manipulations of dissolved N:P. The results are a convincing demonstration of P limitation of invertebrate production in food webs that are based almost exclusively on leaf litter. The plot below shows response ratios of primary consumer production and litter N:P ratio in the five streams over the two years of N and P enrichment (the regression used the average of the two years in each stream). The plot shows that the largest increases in macroinvertebrate production were associated with the largest decreases in the N:P ratio of litter. Well done to Mick for revealing these patterns. Only someone who is familiar with calculating invertebrate production will appreciate what an ungodly amount of work went into a plot like this!