Bud phenology data

This dataset contains phenological observations (stored as numbers from 0-6) of white spruce (3 seed sources), black spruce (1 seed source) and Norway spruce (4 seed sources) buds in spring gathered over 2 years (2016-2017) on trees growing in two plantations that were established in two different blioclimate zones in eastern Canada (the northern temperate forest and the boreal mixedwood forest). For each tree, the terminal bud of all branches belonging to the whorl at breast height were observed weekly. We identified inter- and intraspecies variation in bud break timing and in sensitivity to environmental cues (frost probability, GDD, photoperiod) for each phenological stage. We found that spring frosts and photoperiod control the firsts phenological stages and GDD controls the lasts phenological stages which highlights an important ecological trade-off between the maximizing the growing season length and limit frost damage from too early bud burst.

本数据集包含2016至2017年两年间，针对加拿大东部两个不同生物气候带（北温带森林与北方混交林）内已建立的两处人工林的试验树木开展的云杉春季芽物候观测（phenological observations）数据：观测对象包括3个种源（seed sources）的白云杉（white spruce）、1个种源的黑云杉（black spruce）以及4个种源的挪威云杉（Norway spruce），观测值以0至6的数字存储。针对每株试验树木，研究人员每周对其胸高轮生枝（whorl at breast height）上所有枝条的顶芽（terminal bud）开展观测。本研究明确了各物候期（phenological stage）下，芽萌动时间（bud break timing）及对环境因子（environmental cues）的敏感性存在种间与种内变异。研究发现，春季霜冻与光周期调控早期物候阶段，而生长度日（GDD）调控后期物候阶段，该结果揭示了最大化生长季长度与规避过早芽萌动引发的霜冻危害之间，存在关键的生态权衡。