Melissa (Lissy) Enright, a graduate student in ECOSS at NAU, shared her research on the hydraulics (water movement) of giant redwood trees with the high school students in the iCREATE class at NAU.
Lissy shared some of her background with the students including working on an oceanographic vessel with the Sea Education Association, working for the National Park Service in Hawaii, and for American Conservation Experience as an AmeriCorps Member in both Flagstaff and Alaska! She also worked with Honko, an NGO (non-governmental organization) working in partnership with the coastal communities of Madagascar on mangrove conservation. She showed the students the website for the Student Conservation Association where you can search through their list of opportunities, including those for students under 18 years old!
Lissy's experience helped her to get a "real job" working with the US Forest Service in Alaska doing a Forest Inventory and Assessment. She also worked in Northern California where she now has her research area studying water stress at the top of Redwood trees.
Lissy illustrated how the stems of the tree branches can get embolisms (air bubbles) from high water stress. She climbs the trees using a jumar system and then brings the branches home to Flagstaff to study the hydraulic conductivity of the tree.
Lissy asked the students why the pine needles and branches might be ore water stressed at the top of the trees than down below. Even though the base of the redwood is in an often moist environment, the tops of the trees are more exposed to sun; but the primary reason is that water is pulled all the way up the xylem (water tubes) of the tree from the ground to 250-400 feet! So the top of the tree is more like a dry climate.
Lissy took the students into the laboratory where she measures the hydraulic conductivity of the branches. She had them assist her with several experimental procedures she uses to determine levels of water stress in the redwood trees.
Thank you, Lissy, for the wonderful presentation and the engaging hands-on research in your lab!
Flagstaff STEM Coordinator