Functional leaf and stem traits of the Oaks of the Americas

Leaf and stem trait data: Measured interspecific variation of Quercus (L.) - totaling 15+ functional traits for 135* American oak species. Our goal was to hand-measure/characterize as many North American species as possible. Measurements include: (1) specific leaf area (SLA, mm2 mg), an important leaf economic spectrum (LES) trait associated with leaf lifespan, resource acquisition, and nutrient use (Wright et al., 2004; Reich, 2014), (2) perimeter per unit leaf area (PLA, cm−1), a leaf trait that increases with degree of lobing and decreases with leaf size and is associated with hydraulic conductance and boundary layer resistance for all species (Sack et al., 2003; Kaproth and Cavender‐Bares, 2016), (3) total length of major veins per area (cm−1), associated with leaf hydraulic function (Sack and Scoffoni, 2013), (4) leaf length (mm), (5) petiole length (mm), and (6) stem specific density (g·cm−3), associated with mechanical strength and drought tolerance (Cornelissen et al., 2003; Kunstler et al., 2015). Specimens from sunlit branches were pressed and dried alongside samples collected for herbarium specimens as part of the Oaks of the Americas Project (Hipp et al., 2018).