Ecophysiological aspects and phenotypic plasticity in Eugenia stipitata during the production stage in four landscapes of the Colombian Amazon region

摘要

In the tropics, species management in agroforestry conditions has defined changes for the resources available for plant productive performance. Under the vision of physiological integral evaluation responses in field conditions, we conducted a study of the variations in plasticity and ecophysiological parameters of five /:'. stipitata morphotypes during the production stage in four physiographic units of the Colombian Amazon, recording the daily movements of the variables associated with gas exchange, chlorophyll fluorescence, water balance and phenotypic plasticity during the dry and wet seasons of the region. The responses in the gas exchange variables were significantly influenced by the environment, with the rate of photosynthesis (A), transpiration rate (E), and stomatal conductance (gs) being more affected. The chlorophyll fluorescence reflected a regulatory mechanism for the dissipation of thermal energy that allows these plants to cope with periods of high light intensity, especially duringthe dry season. The negative water potential values, mainly around noon in all of the cases, indicated a moderate water stress as observed during the dry season, matching the reversible photoinhibition processes. Finally, it was noted that, under favorable conditions, such as on the floodplain, high terrace and low terrace stress resistance syndromes were observed, as determined by the adjusted response to the water stress of the dry season; while, in the dissected Amazon floodplain, there were adaptive responses.