6.3 Diagnosing leaf water status and leaf hydraulic strategy
Seasonal midday ΨL values varied across species and stands, but in general, Q. alba experienced a lower overall midday ΨL and a broader range. Larger species-specific declines in midday ΨL occurred in the more arid forest stands (e.g., NC_E chronosequence and MO, Table 1), while the smallest occurred in NC_W 15yo (Fig. 6a). Leaf hydraulic strategy was primarily associated with species (Fndf,ddf = 22.20,p = <0.001), and no influence of age on mean ΨL interquartile ranges were detected (age and age-species interactions not significant). The L. tulipifera andA. saccharum mean ΨL interquartile ranges were indistinguishable, but significantly lower than Q. alba (Fig. 6b). Overall, Q. alba displayed more anisohydric behavior whileL. tulipifera and A. saccharum were more isohydric.