Chlorophyll fluorescence varies more across seasons than leaf water potential in drought-prone plants.

Bruno H.P Rosado,Eduardo A De Mattos

doi:10.1590/0001-3765201620150013

Abstract

Among the effects of environmental change, the intensification of drought events is noteworthy, and tropical vegetation is predicted to be highly vulnerable to it. However, it is not clear how tropical plants in drought-prone habitats will respond to this change. In a coastal sandy plain environment, we evaluated the response of six plant species to water deficits across seasons, the relationship between their morpho-physiological traits, and which traits would be the best descriptors of plants' response to drought. Regardless of leaf succulence and phenology, responses between seasons were most strongly related to chlorophyll fluorescence. In this study we have demonstrated that a better comprehension of how tropical species from drought-prone habitats cope with changes in water availability can be based on seasonal variation in leaf water potential and chlorophyll fluorescence. Temporal variation in leaf water potential and chlorophyll fluorescence was found useful for differentiating between groups of sandy soil species that are responsive or unresponsive to water availability. However, chlorophyll fluorescence appeared to be a more sensitive descriptor of their seasonal and short-term responses.

Highlights

In the current scenario of large-scale environmental change, the search for functional traits which will allow us to predict the response of communities and species to changes in conditions and resources has been identified as one of the 100 fundamental questions in ecology (Sutherland et al 2013)
We selected six shrub species based on variation in leaf succulence and phenology (Rosado and de Mattos 2007) in an area 300 m from the ocean: Clusia hilariana and Byrsonima sericea DC. (Malpighiaceae)
Clusia and Protium had higher values of Ψ throughout, the other species, md except for Erythroxylum, maintained similar values throughout the year, which were consistently lower than the dominant species

Summary

Introduction

In the current scenario of large-scale environmental change, the search for functional traits which will allow us to predict the response of communities and species to changes in conditions and resources has been identified as one of the 100 fundamental questions in ecology (Sutherland et al 2013). Among the effects of environmental change, the intensification of drought events is noteworthy (McDowell et al 2008, 2011), and several studies have identified plant physiological traits that may be descriptors for the responses of plants to water availability (Bartlett et al 2012, Choat et al 2012, Bhaskar and Ackerly 2006). DE MATTOS in tropical dry forests and savannas have been published (Bucci et al 2005, Franco 2002, Choat et al 2006, Méndez-Alonzo et al 2012), it is still unknown how tropical plants in other tropical drought-prone habitats (e.g. coastal sandy plains) will respond to drought, and which are the best traits for predicting this response

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Conclusion