Modelling optimal plant carbon storage

Abstract

As sessile organisms, plants are especially vulnerable to a wide range of abiotic and biotic pressures. Moreover, anthropogenic climate change has been causing increased intensity and frequency of stress events. To predict how environmental stress modifies vegetation function, we need to better understand plant stress tolerance mechanisms. One such mechanism is carbon storage: storage of non-structural carbohydrates provides plants with reserves during a stress period and expedites post-stress recovery. However, storing carbon requires an a priori action that only has a positive effect on survival during future stress, and may be detrimental, in the short-term, by re-directing carbon from other crucial processes such as growth. In this thesis, I focus on exploring the growth-storage trade-off involved in plant carbon storage in the presence of stress. I employ a range of modelling techniques to mathematically characterise the response of the optimal storage utilisation trajectory (OSUT). In Chapter 2, I explore the shape of OSUT during a single stress period. In Chapter 3, I explore the long-term success of alternative storage strategies for a community of plants experiencing stochastic stress events. Whilst Chapter 2 assumed that the evolved strategy is static, that is unrealistic. Hence in Chapter 4, I explore the acclimation of carbon storage to a stochastic environment. The results presented in this thesis identify candidate storage-related allocation traits that can link carbon storage strategies with other observable plant traits and processes. Such work would be vital in improving the representation of carbon storage in models. Therefore, the findings from this thesis provide new insights into how optimal carbon storage may be modelled and, further, underline the importance of capturing the trade-offs of growth-storage and the effects of stochasticity when exploring the process of carbon storage.

Date of Award	2021
Original language	English