Variability in frost occurrence under climate change and consequent risk of damage to trees of western Quebec, Canada

Abstract

Climate change affects timings, frequency, and intensity of frost events in northern ecosystems. However, our understanding of the impacts that frost will have on growth and survival of plants is still limited. When projecting the occurrence of frost, the internal variability and the different underlying physical formulations are two major sources of uncertainty of climate models. We use 50 climate simulations produced by a single-initial large climate ensemble and five climate simulations produced by different pairs of global and regional climate models based on the concentration pathway (RCP 8.5) over a latitudinal transect covering the temperate and boreal ecosystems of western Quebec, Canada, during 1955–2099 to provide a first-order estimate of the relative importance of these two sources of uncertainty on the occurrence of frost, i.e. when air temperature is < 0 °C, and their potential damage to trees. The variation in the date of the last spring frost was larger by 21 days (from 46 to 25 days) for the 50 climate simulations compared to the 5 different pairs of climate models. When considering these two sources of uncertainty in an eco-physiological model simulating the timings of budbreak for trees of northern environment, results show that 20% of climate simulations expect that trees will be exposed to frost even in 2090. Thus, frost damage to trees remains likely under global warming.

The early bud gets the cold: Diverging spring phenology drives exposure to late frost in a Picea mariana [(Mill.) BSP] common garden

“…Because of lower forcing requirements, trees in these regions could be more affected by the advance in budbreak induced by warmer spring conditions. This, in turn, could leave the trees exposed to the risk of late frost, which may become more frequent as spring temperatures variability increases (Chamberlain et al, 2021; Marquis et al, 2022).…”

“…Late frost events are characterised by freezing temperatures after plant leaf‐out in the spring, often causing significant damage to crops and forests (Chamberlain et al, 2019; Rigby & Porporato, 2008). Under climate change, the combination of warmer spring conditions and increased variability in temperature values make late frosts a serious threat, which has received increasing attention in the scientific literature (Chamberlain et al, 2021; Marquis et al, 2022). However, late frosts are discrete weather events, more difficult to predict than long‐term climatic trends and mean values (Jentsch et al, 2007).…”

Leaf phenology as an indicator of ecological integrity

“…Observations show that global warming has advanced leaf emergence for deciduous species over the past five decades (Menzel et al, 2006; Peñuelas & Filella, 2009; Piao et al, 2019) and to a lesser extent delayed leaf senescence (Estiarte & Peñuelas, 2015; Menzel & Fabian, 1999; Peñuelas et al, 2002; Xie et al, 2018). Climate‐driven increases in extreme weather and changes in leaf phenology together may lead to an increased risk of damage from disturbance such as frost, ice storms, herbivory, and hurricanes (Allstadt et al, 2015; Augspurger, 2013; Bascietto et al, 2018; Casson et al, 2019; Delpierre et al, 2017; Lechowicz, 1984; Marquis et al, 2022; Pureswaran et al, 2019; Taylor et al, 2020). Climate change has also led to a change in the frequency of stress from drought or excessive precipitation, due to both an extension of the growing season and an alteration of global hydrology (Čehulić et al, 2019; Charlet de Sauvage et al, 2022; Etzold et al, 2022; Lukasová et al, 2020; Meier et al, 2021; Sangüesa‐Barreda et al, 2021).…”

Local adaptation shapes functional traits and resource allocation in black spruce

“…Budbreak is a transition between dormancy and growth, and needs to be synchronized with environmental conditions in order to avoid the risk of frost damage on vulnerable new tissues 30 . Under climate change, warmer spring temperatures cause an advance in spring phenology, increasing the risk of exposing the young shoots to damaging late-spring frost events 30 , 31 . Late-spring frost damage can occur when below-freezing temperatures hit after budbreak or the first leaf-out.…”