I recieved the results back from the lab some time ago. There were no differences were seen between seabird and non-seabird or between treatments except for Rhabdothamnus solandri, which expressed higher δ15N values in areas of increasingly dense burrow colonies. In this study Rhabdothamnus solandri, as the only member of its genus is hard to generalize, but its family is a bit more widespread. It is a long living, flowing shrub, that requires birds for pollination. This plant expressed higher δN15 values in areas with more seabirds, meaning that of the nitrogen in its leaves, more of it was from a marine source than plants in areas with fewer burrows.
This was unexpected since the seabird colonies were so much more dense than what I had studied in Kauai. I am collaborating with some other researchers who are looking into this topic. I will post more on this as I have time to work on it and as more research comes to light.
This was unexpected since the seabird colonies were so much more dense than what I had studied in Kauai. I am collaborating with some other researchers who are looking into this topic. I will post more on this as I have time to work on it and as more research comes to light.