Timing of cherry tree blooming: Contrasting effects of rising winter low temperatures and early spring temperatures

Abstract

Phenology reflects the interplay of climate and biological development. Early spring phenological phenomena are particularly important because the end of diapause or dormancy is related not only to heat accumulation in the early spring but also probably to winter low temperatures. Although a warmer winter can reduce overwintering mortality in many insects and plants, it also reduces the accumulation of chilling time that often triggers the end of diapause or dormancy. We examined a continuous 67-year time series of the first flowering date of cherry trees and compared three phenological models based on the temperature-dependent developmental rate: (i) the accumulated degree days (ADD) method, (ii) the number of days transferred to a standardized temperature (DTS) method, and (iii) the accumulated developmental progress (ADP) method. The ADP method performed the best but only slightly better than the DTS method. We further explained the residuals from the ADP method by an additive model using the mean winter minimum daily temperatures, the number of days with low temperatures (represented by daily minimum temperature) below a critical low temperature, and the minimum annual extreme temperature. These three temperature variables explained more than 57.5% deviance of the ADP model residuals. Increased mean winter low temperatures can delay the blooming of cherry trees by reducing the accumulation of chilling time, whereas reduced numbers of cold days can shift the blooming to become earlier. Overall, rising winter low temperatures will delay the flowering time, while rising early spring temperatures directly shift earlier the flowering time. The flowering time has been shifted to earlier, and the balance from the opposing effects of rising winter low temperatures and early spring temperatures explains this shift.

Chilling requirements and dormancy evolution in grapevine buds

“…The effect of chilling hours on precocity can be clearly seen, with a reduction of about one day for every 62 CH, within the limits of the experiment (up to around 1000 CH). A similar pattern was observed in apple (Noar et al, 2003), pear (Herter et al, 2001), grapevine (Dokoozlian, 1999), peach (Bruckner et al, 2010;Sugiura et al, 2010), apricot (Campoy et al, 2011) and cherry (Shi et al, 2017) trees, in which reduced budburst time was observed with increased chilling exposure time.…”

A General Leaf Area Geometric Formula Exists for Plants—Evidence from the Simplified Gielis Equation

“…To compare them, we used three datasets of bamboos (datasets 4-6) with different floating ratios, i.e., 3.08%, −4.35%, and 0.43% (Figure 6d-f). The golden ratio was used to divide a dataset into two parts: training set and test set [24]. In practice, we hoped to use a small number of leaves to obtain the estimates of floating ratio in the SGE and fitted results in the GAM.…”

Long‐term changes in the impacts of global warming on leaf phenology of four temperate tree species

“…However, warming climate may also lengthen the time required for meeting the chilling requirement in plants, resulting in delayed leaf unfolding (Ford, Harrington, Bansal, Gould, & St Clair, 2016;Murray, Cannell, & Smith, 1989;Yu, Luedeling, & Xu, 2010). Therefore, the temperature response of spring leaf phenology to climate warming is complex due to variations of forcing and chilling unit accumulation (Fu et al, 2015;Keenan, 2015;Luedeling & Gassner, 2012;Luedeling, Guo, Dai, Leslie, & Blanke, 2013;Shi et al, 2017;Wang, Ge, Dai, & Dai, 2015). Fu et al (2015) reported that spring leaf unfolding became less sensitive to temperature in the period of 1999-2013 as compared to 1980-1994 and stated that the observed decline in temperature sensitivity (S T , shift in days per degree Celsius) is likely to be caused by reduced chilling associated with warming.…”