Author(s): REZENDE, L. F. C.; ARENQUE, B. C.; AIDAR, S. de T.; MOURA, M. S. B. de; RANDOW, C. V.; TOURIGNY, E.; MENEZES, R. S. C.; OMETTO, J. P. H. B.

Summary: Vcmax is the rate of maximum velocity of carboxylation of plants and is considered one of the most critical parameters for changes in vegetation in face of global changes and it has a direct impact on gross primary productivity. Physiological processes are considered the main sources of uncertainties in dynamic global vegetation models (DGVMs). The Caatinga biome, in the semiarid region of northeastern Brazil, is extremely important due to its biodiversity and endemism. In a field work realized in an area of preserved Caatinga forest, measurements of carbon assimilation (in response to light and CO2) were performed on 11 individuals of a native species. These results of Vcmax measurements in Caatinga were compared with parameterization of models, revealing that Vcmax is not well adjusted in several DGVMs. Also, the values obtained in the Caatinga field experiments were very close to empirical values obtained in the Northern hemisphere (Austria). These ecophysiological measurements can contribute in understanding of this biome

Publication year: 2016

Types of publication: Journal article

Unit: Embrapa Semi-arid Region

Keywords: Bioma Caatinga, Caatinga, Dynamic global vegetation models, Plant functional types, Planta nativa, Recurso natural, Vegetação