In just one week, Kyleen Kelly and I will be driving up to Grand Teton National Park in Wyoming to sample endangered white bark pines from the (aptly named) White Bark Pine Moraine Lake watershed. Other researchers have cored lakes in the area for long term records of ecological conditions. Our sampling of watershed trees will provide additional information for interpreting sediment core data and assessing climate change impacts on a high-elevation endangered species.
Kyleen has obtained a permit from GTNP to core 20 white bark pines. Coring is a non-lethal (though slightly destructive) way to sample individual tree rings throughout the life of the tree. A borer (shown in the photo to the right) is used to drill into the tree. The borer is hollow, and so cores out a small cross-section of the tree. This core can then be removed and used to analyze individual ring width patterns, and to perform various biogeochemical analyses of the wood contents of each ring (for example, nitrogen isotope analysis, as discussed in my previous post). Coring leaves a small (a few mm in diameter) hole through the center of the tree. There is a short window of time when this hole may make the tree slightly more susceptible to disease or insects; however, most trees are capable of rapidly sealing off the bore hole to prevent such problems. In fact, if a researcher is too slow in removing the borer from the tree while coring, some trees can respond so quickly as to seal the borer into the tree. Kyleen and I will also sterilize the borer with ethanol between cores so as not to spread disease between trees.
In addition to coring white bark pine, Kyleen and I will also measure diameter at breast height (DBH, a standard measure of tree size) and height of other white bark pines in the area. This will give us an estimate of the age structure of the stand (larger/taller trees being older). At this point, we are unsure of the number of trees in the stand at White Bark Pine Moraine Lake, so we will either sample all the white bark pines (if the stand is small), or set up transects to randomly sample throughout the stand (if the stand is large). We will also take detailed notes and photos of the general site characteristics, as well as micro-conditions of each cored tree. We also plan to document other vegetation present to aid in the identification of macrofossils within the White Bark Pine Moraine Lake sediment core.
We will leave Kansas on Monday, driving out to Wyoming over a two-day roadtrip. We will then stay at GTNP for two weeks to provide ample time for all the sampling described above. We hope to also have a little time for personal site-seeing, if the sampling goes smoothly.
Check back here for exciting updates (and photos!) of our beautiful field site!