Gas exchanges and photosynthetic efficiency in sub-forest species from Atlantic Forest

Magnólia Martins Alves,Renata Ranielly Pedroza Cruz,Manoel Bandeira De Albuquerque,Mário Luiz Farias Cavalcanti

doi:10.33448/rsd-v9i5.2870

Magnólia Martins Alves, Renata Ranielly Pedroza Cruz + Show 2 more

Open Access

https://doi.org/10.33448/rsd-v9i5.2870

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Abstract

The availability of light is one of the factors that most limits the photosynthesis of juvenile trees in the understory of the forest. The study was carried out in the Mata do Pau-Ferro State Park, located in the city of Areia, PB. The objective of this study was to evaluate how gas exchanges occur in individuals of Psychotria colorata (Willd. Ex Roem & Schult.), Senna georgica Irwin & Barneby, Himatanthus phagedaenicus (Mart.) Woodson, Solanum swartzianum Roem. & Schult, Psychotria carthagenensis Jacq.e Psychotria hoffmannseggiana (Willd. ex Schult.) in the understory of a remnant of Mata Atlântica. The rate of photosynthesis (A), transpiration (E), stomatal conductance (Gs), internal CO2 concentration (Ci) leaf temperature-air temperature (°C), and internal carbon (Ci), instantaneous efficiency of water use (EUA) (A/E), Intrinsic efficiency of water use (EiUC) (A/Gs) and the intrinsic efficiency of carboxylation (ratio A/Ci). The rates of maximum photosynthesis (A), photosynthesis (E) and stomatal conductance (Gs) were shown to be influenced by the time of day, as there was no interference of external factors in the diurnal patterns of gas exchange, variations are due to endogenous factors, probably due to the circadian rhythm. The parameter of the gas exchange of sub-forest species responds differently, in the small variations in the luminosity levels of the forest understory

Highlights

The Atlantic forest is recognized worldwide as the second largest tropical forest in the Americas (Myers et al, 2000)
The availability of light is one of the factors that most limits the photosynthesis of juvenile trees in the understory of the forest
The objective of this study was to evaluate how gas exchanges occur in individuals of Psychotria colorata

Summary

Introduction

The Atlantic forest is recognized worldwide as the second largest tropical forest in the Americas (Myers et al, 2000). The Atlantic Forest of Northeast Brazil hosts several pioneer species, which are divided into the portions of Ombrophylous Forest, Semidecidual and Decidual Seasonal Forest, occupying a currently area of about 2.21% of its original territory. These fragments are present in the states of Alagoas, Bahia, Ceará, Paraíba and Pernambuco (Alves et al, 2015). The light intensity is one of the main factors for plant growth and development, responsible for changes in stomatal conductance, remaining high until the leaf water potential is reduced, inducing stomata closure (Sesma et al, 2009). Ex Roem & Schult.), Senna georgica Irwin & Barneby, Himatanthus phagedaenicus (Mart.) Woodson, Solanum swartzianum Roem. & Schult, Psychotria carthagenensis Jacq.and Psychotria hoffmannseggiana (Willd. ex Schult.) in the sub-forest of a remnant of Atlantic Forest

Methodology

Results and Discussions

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Conclusion