Analysis of gas exchange in trees of the Caatinga, Brazil

Abstract

In the Brazilian semiarid region, the high temperatures in association with the high level of solar radiation and variations in the concentration of CO2 which of focus on plants may influence the physical conformation of vegetables and their growth. On the basis of the above, the objective of this work to evaluate the content of gas exchange and chlorophyll in plants typical of Caatinga, associating possible interference of the power plant Borborema thermal S/A. the study carried out in the period of 2014-2018 with botanical species in two areas of the caatinga of Paraiba. To analyze the variables used the infra Red Gas Analyzer (RGA) and the SPAD. In using SPAD equipment it was found that the species had higher SPAD value were Aspidosperma pyrifolium Mart., (SPAD=50) P300. As the analyzes of gas exchange by the LCpro+, obtained greater record in plant Aspidosperma pyrifolium Mart. In point (P400). The maximum values of E and points were recorded (P600) (E=3.44>335 mmol.H2O.m-².s-¹) and (P100) (E=3.16mmol.H2O.m-².s-¹), both second collection. The first collection the highest registered was E=2.30mmol.H2O.m-².s-¹ (P600), Ziziphus species Joazeiro. In relation of the Tukey test, it was found that the transpiration of tree species, were higher in the second collection, the range of confidence (a, b) were significantly different. It was concluded that the indexes were higher by SPAD the occasion of the 2ª collection. The Ci presented low variation between the two periods. It was so, a non-correlation between the collections and areas surveyed.