Climatic warming and its effect on bud burst and risk of frost damage to white spruce in Canada

Abstract

Temperature data from ten weather stations across Canada were Les donnees de temperature de dix stations meteorologiques used to model the effects of climate warming on the timing of bud canadiennes ont ete utilisees pour modeliser les effets du rechaufburst and the risk of frost damage to white spruce (Picea glaufement climatique sur I'epoque de l'eclosion des bourgeons et sur ca (Moench) Voss). There was evidence of increasingly earlier le risque de gel tardif dans le cas de I'epinette blanche (Picea glaudates of bud break over the course of this century at half of the ca (Moench) Voss). de debourrement des bourgeons (accumulation la plus hiitive de that bud burst will occur two to four weeks sooner than was the degre-jour). Le risque de degiit par le gel pour la plupart des stacase during 1961 to 1980 at all stations, but that this will genertions au cours des annees 1980 a ete habituellement plus grand ally be accompanied by decreased risk of frost after bud burst.que toute autre periode anterieure. Les donnees meteorologiques However, while the expected trend is one of reduced frost risk in modelisees pour un rechauffement climatique de 5(C predisent the future, as the climate gradually warms frost risk is expected que le debourrement des bourgeons suwiendra de deux a quatre to fluctuate upward or downward depending on interactions semaines plus t6t qu'il n'a ete le cas de 1961 a 1980 pour toutes between provenance and local climate.les stations, mais que cela sera generalement accompagne d'une diminution du risque de gel apres le debourrement des bourgeons. Key words: bud burst, climate warming, dormancy, freezing damToutefois, mime si la tendance attendue en est une de reduction age, frost, global climate change, Picea glauca, white spruce des risque de gel dans I'avenir, alors que le climat se rechauffera le risque de gel pourrait fluctuer a la hausse ou a la baisse selon les interactions survenant entre la provenance et le climat local.

A case of severe frost damage prior to budbreak in young conifers in Northeastern Ontario: Consequence of climate change?

“…In fact, 2007 was the first year in the 90-year meteorological record at Kapuskasing with daily minimum temperatures of -8 o C or colder after cumulative GDD reached 100. Contrary to Colombo's (1998) projections for the boreal forest region in Canada, earlier budbreak with climatic warming would likely be associated with increased frost risk at Kapuskasing. In Table 4, individual years from 1918 to 2007 are grouped by estimated Julian day of budbreak (EDB) for 100 GDD into early (EDB < 140, averaged 134), mid (140 ≤ EDB < 150, averaged 144), and late (EDB ≥ 150, averaged 154) budbreak date.…”

“…During early spring, most trees in cold and temperate climates are in a state of shoot dormancy imposed by cold weather, called rest (Saxe et al 2001). Trees at rest resume growth (and thus lose cold hardiness) in direct response to warming temperatures (Colombo 1998, Saxe et al 2001. The date of budbreak and loss of cold hardiness for resting trees can be predicted based on the accumulation of temperatures above a threshold (or base, usually 5 o C) in the spring, termed growing degree days (GDD) (Sarvas 1972, Colombo 1998.…”

“…Trees at rest resume growth (and thus lose cold hardiness) in direct response to warming temperatures (Colombo 1998, Saxe et al 2001. The date of budbreak and loss of cold hardiness for resting trees can be predicted based on the accumulation of temperatures above a threshold (or base, usually 5 o C) in the spring, termed growing degree days (GDD) (Sarvas 1972, Colombo 1998. In Kapuskasing during April and May 2007, the accumulation of GDD was about 1 week earlier than the 1981 to 2007 average, a period that was also close to a week earlier in cumulative GDD from the previous periods (Table 3).…”

A case of extensive conifer needle browning in northwestern Ontario in 2012: Winter drying or freezing damage?

“…Since the 1958 incident occurred at least 50 years ago, ascribing present-day examples to climate change would require an increase in the frequency and severity of such events, as reported by Man et al (2009) and Augspurger (2013) through phenology observations and temperature records. As the relationship between freezing conditions and warming climate likely varies by geographical region (Colombo 1998), monitoring forest health and reporting such climatically induced damage will be important to document climate change effects on forests in coming decades.…”

Evidence for a persistent and extensive greening trend in Eurasia inferred from satellite vegetation index data

“…The northern latitudes experienced enhanced warming, especially during the winter and spring periods. The biotic response to warming can be assessed in multiple ways, e.g., phenological changes in plants [Myneni et al, 1997;Colombo, 1998;Schwartz, 1998;Bradley et al, 1999;Menzel and Fabian, 1999;Cayan et al, 2001;Fitzjarrald et al, 2001;Zhou et al, 2001] and changes in animal behavior [Crick et al, 1997;Brown et al, 1999;Crick and Sparks, 1999;Parmesan et al, 1999;Thomas and Lennon, 1999].…”