Canadian Forest Service Publications
Synchronisms between bud and cambium phenology in black spruce: early-flushing provenances exhibit early xylem formation. 2017. Perrin, M.; Rossi, S.; Isabel, N. Tree Physiol. 37: 593-603.
Issued by: Laurentian Forestry Centre
Catalog ID: 38380
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Bud and cambial phenology represent the adaptation of species to the local environment that allows the growing season to be maximized while minimizing the risk of frost for the developing tissues. The temporal relationship between the apical and radial meristems can help in the understanding of tree growth as a whole process. The aim of this study was to compare cambial phenology in black spruce (Picea mariana (Mill.) B.S.P.) provenances classified as early and late bud flushing. The different phases of cambial phenology were assessed on wood microcores sampled weekly from April to October in 2014 and 2015 from 61 trees growing in a provenance trial in Quebec, Canada. Trees showing an early bud flush also exhibited early reactivation of xylem differentiation, although an average difference of 12 days for buds corresponded to small although significant differences of 4 days for xylem. Provenances with early bud flush had an early bud set and completed xylem formation earlier than late bud flush provenances. No significant difference in the period of xylem formation and total growth was observed between the flushing classes. Our results demonstrate that the ecotype differentiation of black spruce provenances represented by the phenological adaptation of buds to the local climate corresponds to specific growth dynamics of the xylem.
Plain Language Summary
In this study, the researchers demonstrated that different black spruce provenances, when subjected to the same environmental conditions, exhibit different bud growth dynamics, attesting to the black spruce’s potential for adaptation. The results also show that bud growth dynamics are synchronized with wood formation dynamics.
The researchers compared the dynamics of wood formation among seven different black spruce provenances, representing two bud break categories (early and late). It was observed that black spruce provenances with an early bud break also exhibit early wood formation.
The dynamics of bud growth and wood formation are indicators of a species’ adaptation to its environment. These results improve our understanding of black spruce growth and adaptation mechanisms in the context of climate change.