Aspectos ecofisiológicos de dez espécies em uma área de caatinga no município de Cabaceiras, Paraíba, Brasil

In order to evaluate the transpiration (E), diffusive resistance (Rs), leaf temperature (Tf) and proline contents in ten species occurring in the “caatinga” dry forest in the beginning of the dry season, a research project was developed at Cabaceiras County, Paraiba State, in Brazil. A randomized design was used consisting of ten species (Capparis flexuosa, Ziziphus joazeiro, Schinopsis brasiliensis, Croton sonderianus, Bauhinia cheilantha, Caesalpinia pyramidalis, Maytenus rigida, Aspidosperma pyrifolium, Croton campestris e Jatropha pohliana, four hours of assessment (7, 10 a.m. and 13, 16 p.m.) with four replications. The Tf was higher than the air temperature for all assessments, but Capparis flexuosa maintained similar Tf values in the hottest hours of the day. Differences in the magnitude of values among species and hours of evaluation were observed. C. flexuosa presented the highest values of E at 10:00 a.m. and 1:00 p.m.. The shortest values of E were observed in C. campestris and J. pohliana. This latter specie showed the biggest Rs. Variation in proline contents in the leaves among the species was verified. C. pyramidalis, B. cheilantha and C. campestris showed the biggest proline concentration. The species studied use different ways to survive under water deficit periods through stomactic control and osmotic adjustment.