How will Eucalyptus tree species respond to global climate change? : a comparison of temperature responses of photosynthesis

Abstract

The response of leaf net photosynthesis (An) to temperature, including diurnal temperature fluctuations and extreme high temperature events, is a critical physiological response determining where plants can grow and survive. Plants commonly show flexible acclimation of leaf photosynthesis to temperatures that relate to the thermal regime in which they are grown, across different seasons of the year, and across different geographical regions experiencing different climates. However, such responses have been found to be highly variable among species, and have not yet been well quantified. Therefore, the overall research goal for this thesis is to contribute to the knowledge of how Eucalyptus species may respond to climate, in particular seasonal temperature changes, via (i) quantifying the relative importance of three key underlying processes in controlling the response of photosynthesis to temperature, and (ii) evaluating the sensitivity of photosynthetic traits to fluctuations in growth temperatures. The main hypothesis is that warm-climate species should exhibit higher thermal optima and heat tolerance of photosynthesis than do cool-climate species.

Date of Award	2012
Original language	English