Predawn Leaf Water Potential of Oak-Hickory Forest at Missouri Ozark (MOFLUX) Site: 2004-2020

Measurements of predawn leaf water potential (PLWP) have been made at weekly to biweekly intervals during the 2004 to 2020 growing seasons of the second-growth upland oak-hickory forests at the Missouri Ozark AmeriFlux (MOFLUX) site. The MOFLUX site is located in the University of Missouri Baskett Wildlife Research area (BWREA), situated in the Ozark Border Region of central Missouri, USA. More recent data will be added periodically. In each year, except for 2004, the first measurements occurred in mid-May. In all years, the last measurements took place in late October. Leaf samples were collected weekly or biweekly before dawn from canopy and sapling individuals of the common tree species at the site. A total of 20–21 samples were obtained each day with 6–7 taken from white oak (Quercus alba L.), and the rest, with at least two samples per species, distributed among black oak (Q. velutina Lam.), sugar maple (Acer saccharum Marsh.), shagbark hickory (Carya ovata (Mill.) K. Koch), white ash (Fraxinus americana L.), and eastern redcedar (Juniperus virginiana L.), roughly in proportion to their relative stem abundance in the stand.