Abstract:
Objective The response of dormancy release to chilling temperatures is fundamental for understanding how plants adapt to environment. This paper aims to explore different response patterns of tree species from various latitudes in China, which can provide experimental evidence and theoretical support for phenological research.
Method Representative tree species from high (42°N), middle (36°N), and low (30°N) latitudes in eastern China were selected for controlled experiments by climate chambers. Budburst timing and budburst rates were recorded following continuous chilling durations. Two exponential models were used to quantitatively analyze species-specific responses of budburst percentage and timing to chilling conditions, and latitudinal differences in rates of rest break were further compared.
Result High-latitude tree species showed the highest growth rate of budburst percentage and the fastest decay rate of forcing requirement, indicating that they were more sensitive to chilling temperature. Mid-latitude tree species showed the highest rate of rest break, and the shortest average germination time, suggesting greater chilling efficiency. In contrast, low-latitude species showed the highest budburst percentage without chilling accumulation but the longest mean days to budburst, along with the largest coefficients of variation in key indicators, suggesting greater interspecific variability.
Conclusion The mechanisms by which dormancy release responds to chilling in tree species vary along a latitude gradient. High-latitude tree species exhibite not only stronger dependence on chilling condition but also faster responses; mid-latitude tree species show greater adaptive capacity; and low-latitude evergreen tree species display highly heterogeneous response patterns. These findings enhance our understanding of chilling adaptation strategies across ecological types and offer theoretical support for forest regeneration, species introduction, and cultivation zoning under future climate warming scenarios.
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