This year the weather did a good job delaying the start of the planned simultaneous nitrogen isotope additions to our four focal streams (two warm, two cold), as we cannot start them if the streams are too high. We finally got a forecast for a break in the weather, so Mick and Jon started the drippers yesterday evening (in truly awful weather, as it happened). The good weather has now arrived and all 8 drippers (one for ammonium nitrate and one for 15N-enriched ammonium chloride and potassium nitrate in each stream) were behaving well when we changed the batteries after one day out of the scheduled five days of isotope addition. Fingers crossed that those five days go off without a hitch.
Tomorrow we take our first food web samples from the four streams, followed two days later by comprehensive water sampling for nitrogen concentrations and isotopes. More posts to follow.