Estimation of chlorophyll in Quercus leaves using a portable chlorophyll meter: effects of species and leaf age

• The potential of a chlorophyll meter (CCM-200, Opti-Sciences, Tyngsboro, MA, USA) for the estimation of total leaf chlorophyll contents was evaluated in leaves of different developmental stages for Quercus pyrenaica Willd., Q. faginea Lam., Q. suber L. and Q. ilex L. subsp. ballota (Desf.) Samp. • For all species and leaf stages, a strong non-linear relationship ( P < 0.0001) was found between the chlorophyll content index (CCI) and leaf chlorophyll content per unit area. In all species, the slope of the CCI-chlorophyll content relationship varied during leaf development, suggesting that caution should be exercised when using the CCM-200, since the interpretation of CCI readings should be limited to samples of similar leaf age. Also, the data indicate that the models should also be speciesspecific, owing to differences in the intercept and/or slope of the equations. • The addition of fresh LMA as a complementary parameter improved the accuracy of chlorophyll estimation in non-species-specific equations to a considerable extent when leaf samples of similar development were considered. • After due consideration, it may be concluded that the CCM-200 chlorophyll meter is a reliable method for acquiring an estimation of chlorophyll contents in Mediterranean Quercus species, with potential use as an effective tool in forest management.