Phenological physiology: seasonal patterns of plant stress tolerance in a changing climate

Abstract

The physiological challenges posed by climate change for seasonal, perennial plants include increased risk of heat waves, postbudbreak freezing ('false springs'), and droughts. Although considerable physiological work has shown that the traits conferring tolerance to these stressors thermotolerance, cold hardiness, and water deficit stress, respectivelyare not static in time, they are frequently treated as such. In this review, I synthesize the recent literature on predictable seasonaland therefore, phenologicalpatterns of acclimation and deacclimation to heat, cold, and water-deficit stress in perennials, focusing on woody plants native to temperate climates. I highlight promising, high-throughput techniques for quantifying thermotolerance, cold hardiness, and drought tolerance. For each of these forms of stress tolerance, I summarize the current balance of evidence regarding temporal patterns over the course of a year and suggest a characteristic temporal scale in these responses to environmental stress. In doing so, I offer a synthetic framework of 'phenological physiology', in which understanding and leveraging seasonally recurring (phenological) patterns of physiological stress acclimation can facilitate climate change adaptation and mitigation.

Temperate woody species across the angiosperm phylogeny acquire tolerance to water deficit stress during the growing season

“…budbreak, senescence) and physiological processes (e.g. cold hardiness), drought tolerance tends to display relatively predictable temporal patterns on a seasonal basis, which is to say that it is phenological (Grossman, 2023).…”

“…Such seasonally recurring or phenological patterns in physiological stress tolerance reflect plants' already existing capacity to tolerate the sorts of stress associated with ongoing global change (Grossman, 2023). Yet our understanding of phenological dynamics in drought stress tolerance is limited.…”

Application of the thermal death time model in predicting thermal damage accumulation in plants

“…Consequently, it offers a more detailed evaluation of how a specific level of homeostatic failure for a given trait relates to overall fitness and mortality. In a similar way, the TDT model may potentially be a useful tool to quantify and predict the temperature-dependent accumulation of damage that indirectly trigger phenological transitions such as flowering, fruiting and leaf senescence (Bahuguna & Jagadish, 2015; Vitra et al, 2017; Grossman, 2023). Hence, the TDT model could offer mechanistic insight into the adaptive potential of populations, communities, and different genotypes in the context of climate change.…”

Spectral ecophysiology: hyperspectral pressure–volume curves to estimate leaf turgor loss

“…However, recent work has also uncovered new questions that remain unexplored. For example, is TLP fixed or does it vary within a given species, community, individual, or across phenology (Bartlett et al, 2014;Maréchaux et al, 2015Maréchaux et al, , 2016Sjöman et al, 2015;Hirons et al, 2020;Grossman, 2023)? This and many other urgent questions remain understudied or unanswered largely due to intrinsic limitations of the methods currently used to collect TLP data.…”