Theses and Dissertations

INFLUENCE OF PRETREATMENTS ON PHYSIOLOGICAL STATUS AND POST-PLANTING SURVIVAL OF THORNFOREST SEEDLINGS IN A RESTORATION CONTEXT

Douglas Evan Mainhart, The University of Texas Rio Grande Valley

Copyright 2023 The Author. All Rights Reserved.

Abstract

Semi-arid ecosystems across the globe have faced land conversion posing a threat to the important ecosystem services they provide. Revegetation-centered restoration efforts in arid regions have low success due to limited water availability and higher temperatures. Typically, practitioners utilize methods that modify field conditions around seedlings to mitigate these stressors. I evaluated the efficacy of in-nursery treatments to improve plant water status. Three pretreatments were applied: elevated CO2, drought hardening, and an antitranspirant foliar spray. My goal was to understand how these pretreatments would impact survival and growth in the field and what physiological traits they altered. Elevated CO2 and drought treatments significantly increased osmotic potential in two of the species. The antitranspirant significantly reduced stomatal conductance for at least four days after treatment. Treatments modified plant physiology and showed signs of reducing water loss but had no impact on survival or growth in the field under favorable weather conditions.