Because of this richness and the complex conditions of this zone, it is vital for the economy of that region. They are very, very rich in biodiversity. In nature ecosystems transition from one to another gradually or abruptly. These transition zones are extremely important from an ecological and economic point of view. R package version 1.42.1.Have you ever wondered why floodplains host such a variety of life? Why fishes tend to congregate in estuaries for spawning? Why humans have thrived for so long along floodplains? Spring 2007 warmth and frost: phenology, damage and refoliation in a temperate deciduous forest. Phenological data series of cherry tree flowering in Kyoto, Japan, and its application to reconstruction of springtime temperatures since the 9th century. Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers. (eds.) In Press.Īntonucci S., Rossi S., Deslauriers A., Lombardi F., Marchetti M., Tognetti R. An IPCC Special Report on the impacts of global warming of 1.5☌ above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. P., Solecki W., Aragón-Durand F., Cramer W., Humphreys S., et al. Picea bud phenology growing degree-days leaf-out photoperiod spring frost temperature thermal acclimation.Ĭopyright © 2020 Marquis, Bergeron, Simard and Tremblay.Īllen M. Our results call for adapting the temperature-driven hypotheses of ecophysiological models predicting leaf-out to include spring frost probability. The high photoperiod sensitivity in white spruces could counterbalance climate warming and limit future premature leaf-out, whereas the low photoperiod sensitivity in black spruce should not restrain leaf-out advancement with climate warming. Onset of spruce bud flush is driven by spring frosts and photoperiod, but once started, bud phenology responds to temperature. At intraspecies level, the two southern white spruce seed sources opened their buds earlier than the local source and were more sensitive to photoperiod, which increased their exposure to spring frosts. Photoperiod sensitivity was higher for white spruce compared to black and Norway spruce and reached its maximum in the temperate forest. Buds of all spruce species were sensitive to frost probability for early phenological stages, whereas growing degree-days controlled the remaining stages. At both plantation sites, white spruce bud flush began and ended earlier compared to black and Norway spruce. We used mixed binomial regressions and AICc model selection to determine the best environmental variables predicting each transition from one stage of bud phenology to the next. We expected that bud break timing for boreal species and seed sources would be better synchronized with the decrease in frost probability than for nonlocal species and seed sources. We aimed to determine inter- and intraspecies variations in bud break timing and sensitivity to air temperature and photoperiod. We monitored bud flush phenology of three white spruce seed sources (one local seed source from the boreal mixedwood forest and two seed sources from the temperate forest), one black spruce seed source originating from the boreal mixedwood forest and four nonlocal Norway spruce seed sources in 20 in two plantations located on both sides of the temperate-boreal mixedwood forest ecotone in eastern Canada (Quebec). We hypothesized that due to their damaging effect on buds, spring frosts exert a stronger control on bud phenology than do growing degree-days. Climate warming-driven early leaf-out is expected to increase forest productivity but concurrently increases leaf exposure to spring frosts, which could reduce forests' net productivity.
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