Understanding variation in root and shoot growth phenology among species is crucial to understanding underlying mechanisms of temporal niche differentiation. However, little is known about the relationship between root and shoot phenology, or how this relationship varies among functional traits. We examined fine root and shoot phenology of 42 seedlings representing a variety of woody species that inhabit the cool temperate forests of northern Japan. Some aspects of phenology were common to the pool of species examined: we found positive relationships between root and shoot phenology for the end of growth, and for the duration of growth, but not for the start of growth. Further, seedlings that started root growth relatively early also ended root growth relatively late. Other aspects of phenology varied predictably with functional traits, i.e. leaf habit and successional status: first, root growth in evergreen species started significantly earlier and ended later than in deciduous species; second, early successional species had the longest duration of shoot growth among all successional types. Our results suggest that niche differentiation may be promoted by differences in phenology between root and shoots, likely contributing to the co‐existence of woody seedlings in temperate forests.

中文翻译：

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温带木本植物幼苗的同步和异步根冠芽物候

了解物种之间的根和芽生长物候变化对理解时间生态位分化的潜在机制至关重要。然而，关于根和芽物候学之间的关系，或这种关系在功能性状之间如何变化的了解甚少。我们研究了42种幼苗的细根和芽物候物，这些幼苗代表居住在日本北部凉爽温带森林中的各种木本物种。物候方面的某些方面对于所检查物种的库而言是共有的：我们发现，根与茎的物候关系对于生长的结束，生长的持续时间而不是生长的开始具有正相关关系。此外，相对较早开始根生长的幼苗也相对较晚结束根生长。物候学的其他方面随功能特征而变化，即 叶片习性和演替状态：首先，常绿树种的根系生长比落叶树种更早开始，而结束则晚于落叶树种。其次，在所有演替类型中，早期演替物种的芽生持续时间最长。我们的结果表明，根与芽之间物候的差异可能促进了生态位的分化，这可能有助于温带森林中木本幼苗的共存。