Leaf traits, sclerophylly and growth habits in plant species of a semiarid environment

• DOI: 10.1007/s40415-017-0416-x
• Publication Date: 2017-10-19T14:53:34Z
• Authors: Angélica Guerra; Edna Scremin-Dias
• Keywords: 0106 biological sciences; 15. Life on land; 01 natural sciences

Plants that grow in semiarid environments can sustain a positive equilibrium between water absorption and loss. This equilibrium is reminiscent of structural traits acquired throughout their evolutionary history. Woody species often possess sclerophyllous characteristics when growing in dry environments. Herbs on the other hand commonly shed leaves during unfavorable conditions, such as drought, allowing them to grow and establish themselves rapidly, and therefore are less sclerophyllous. Based on observations of species representing different growth habits, and considering xeric habitats, we raised the hypothesis that woody species will posses sclerophyllous traits and that these traits will vary among growth habits. We evaluated morphoanatomical traits that were previously described in the literature as being adaptations to arid environments, of 16 species, of four different growth habits, that co-occur in the Brazilian “Chaco”. Only vine species showed adaptive convergence to dry environments. Woody species were found to possess sclerophyllous traits, including thicker leaves, well-developed palisade parenchyma and the presence of sclerenchyma. Herbaceous species exhibited mesomorphic traits, including larger leaves and little or no sclerenchyma. We concluded that all the analyzed species possess adaptations to the dry environment, although not all of them are sclerophyllous. As expected, woody species and herbaceous species possess different strategies for adapting to environmental conditions.