milr] we don't ually sethem until ey're a w years d. you could imagine how lnerablet is in tho arid sos getting ough wat through ose longot summe. buif mom w living therfor 4,00years, then that was a pretty good place. the estimates are less than 1% of survival, but if they survive those first few years, they're pretty good to go. and really there isn't much that kills the bristlecone. (upbeat music) (wind whirling) as an historical ecologist, i think a lot about times when there were trees, but no humans. and so sometimes i'll go to places where there was before humans in my mind, because i know those places well from studying them where pines evolved and the bristlecones and the mber pin forests e those aces. am interestein trying tundersta how ese treein a mounta environnt torated hioric tural clate chge, because think that cane useful for derstandg what will comin the fure thugh the owth ringof the wd. i can constrt the pa climate and i n know h they resnded. soo see a 000 yearld tree and tohink of w much it'endured anwhat is le to