Assessing foliar chlorophyll contents with the SPAD-502 chlorophyll meter: a calibration test with thirteen tree species of tropical rainforest in French Guiana
2010
Coste, Sabrina | Baraloto, Christopher | Leroy, Céline | Marcon, Eric | Renaud, Amélie | Richardson, Andrew | Roggy, Jean-Christophe | Schimann, Heidy | Uddling, Johan | Hérault, Bruno
Chlorophyll meters such as the SPAD-502 offer a simple, inexpensive and rapid method to estimate foliar chlorophyll content. However, values provided by SPAD-502 are unitless and require empirical calibrations between SPAD units and extracted chlorophyll values. [br/]Leaves of 13 tree species from the tropical rain forest in French Guiana were sampled to select the most appropriate calibration model among the often-used linear, polynomial and exponential models, in addition to a novel homographic model that has a natural asymptote. [br/]The homographic model best accurately predicted total chlorophyll content (μg cm−2) from SPAD units (R2 = 0.89). Interspecific differences in the homographic model parameters explain less than 7% of the variation in chlorophyll content in our data set. [br/]The utility of the general homographic model for a variety of research and management applications clearly outweighs the slight loss of model accuracy due to the abandon of the species’ effect.
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