Relationship between hydraulic structure and xylem anatomy in Chamaecrista species along the climatic gradient

Abstract

The ecological heterogeneity of tropical ecosystems is related to the high diversity of plant species. The growth and survival of these species depend on morphological and functional traits, such as wood anatomy and water transport capacity. In this project we will investigate how the vascular structure of the xylem is related to the hydraulic functions along of climatic gradient, especially water availability; seeking to understand how this relationship of form and function evolved throughout history in a highly diverse lineage of legumes in native Brazilian ecosystems. For this, the anatomical structure of the xylem and the efficiency, safety and hydraulic safety margin of 15 species of Chamaecrista that live in different climatic conditions will be analyzed quantitatively, sampling species from the Caatinga, Cerrado and Campos Rupestres. We expect to find different evolutionary solutions of the xylem vascular system and a diversification of hydraulic strategies, with the variation of climatic conditions being determinant for the evolution of the relationship between xylem anatomy (shape) and hydraulic efficiency- safety (function) in this plant lineage. The importance of investigating this knowledge gap is to understand in more depth the relationship between form and function in plant lineages that have diversified in tropical ecosystems, considering the historical context that connects the species. Furthermore, the most likely explanation for what we expect to find is that ecological filters, specially hydraulic gradient, and evolutionary history determine various aspects of the wood anatomy and hydraulic structure of plants, whose disruption needs to be investigated experimentally. This project is linked and will bring relevant contributions to the ongoing project Auxilio Jovem Pesquisador BIOTA coordinated by Prof. Anselmo Nogueira (2019/19544-7).