PT Journal
AU Colin, F
   Sanjines, A
   Fortin, M
   Bontemps, J
   Nicolini, E
TI Fagus sylvatica trunk epicormics in relation to primary and secondary growth
SO Annals of Botany
JI Ann. Bot.
PY 2012
BP 995
EP 1005
VL 110
IS 5
DE epicormics; European beech; Fagus sylvatica; mixed ZIP models; ontogeny; radial growth; sprouting
AB Background and AimsEuropean beech epicormics have received far less attention than epicormics of other species, especially sessile oak. However, previous work on beech has demonstrated that there is a negative effect of radial growth on trunk sprouting, while more recent investigations on sessile oak proved a strong positive influence of the presence of epicormics. The aims of this study were, first, to make a general quantification of the epicormics present along beech stems and, secondly, to test the effects of both radial growth and epicormic frequency on sprouting. MethodsIn order to test the effect of radial growth, ten forked individuals were sampled, with a dominant and a dominated fork of almost equal length for every individual. To test the effects of primary growth and epicormic frequency, on the last 17 annual shoots of each fork arm, the number of axillary buds, shoot length, ring width profiles, epicormic shoots and other epicormics were carefully recorded. Key ResultsThe distribution of annual shoot length, radial growth profiles and parallel frequencies of all epicormics are presented. The latter frequencies were parallel to the annual shoot lengths, nearly equivalent for both arms of each tree, and radial growth profiles included very narrow rings in the lowest annual shoots and even missing rings in the dominated arms alone. The location of the latent buds and the epicormics was mainly at branch base, while epicormic shoots, bud clusters and spheroblasts were present mainly in the lowest annual shoots investigated. Using a zero-inflated mixed model, sprouting was shown to depend positively on epicormic frequency and negatively on radial growth. ConclusionsSupport for a trade-off between cambial activity and sprouting is put forward. Sprouting mainly depends on the frequency of epicormics. Between-and within-tree variability of the epicormic composition in a given species may thus have fundamental and applied implications. © 2012 The Author.
ER