Estudo comparativo da influência climática sobre a morfologia de plantas lenhosas da Caatinga nordestina e da Amazônia (Bacia do Rio Xingu)

Abstract

The analysis of the effects of some ecological parameters such as: water availability, temperature, seasonality, altitude and geographical distribution, on qualitative and quantitative anatomical characteristics, has demonstrated a special relationship between wood structures and climatic factors. In this context, this work aims to study, the anatomical pattern of wood structures of plants inhabiting opposite climatic conditions. The Amazon region was chosen, with species occurring in the dryland forest of the Xingu River basin and the Caatinga of the Northeast, with species occurring in Ceará, Piauí, Pernambuco and Bahia. The methodology used was the standard one for the anatomical study of wood, using histological sections and slides of macerated material. The technical terms used in the anatomical description are in accordance with the International Association of Wood Anatomists/IAWA. The data analysis was done in the digital image and analysis system MOCHA. A total of 72 species, distributed among 53 genera and 28 families, were studied for the Caatinga and 52 species distributed among 51 genera and 31 families, for the Amazon. A total of 71% of the Caatinga species had an average length of the vessel elements between 100-300 mm, which did not exceed 10% of the Amazon species, where the largest number of species, 51%, were in the 300-500 mm range. Besides this, other differences were also found in the diameter and arrangement of the vessels, number of vessels per mm, size of the rays, distribution of the axial parenchyma, etc. The anatomical structures of the analyzed woods for the two distinct regions, in general, showed a great heterogeneity between them. The presence of qualitative anatomical aspects and also the use of quantitative characters contributed to show the impacts of the environment on the wood anatomy.