Rj. Dungan, Whole-tree winter leaf-loss in wineberry (Aristotelia serrata, Elaeocarpaceae) is not related to mean air temperature, NZ J BOTANY, 39(3), 2001, pp. 547-550
Winter leaf-loss of wineberry (Aristotelia serrata) was measured at a range
of sites in the South Island of New Zealand in early spring to investigate
the temperature dependence of deciduousness in this species. The number of
leaves emerged over the growing season on both shaded and exposed shoots i
ncreased with temperature across sites. There was consistently greater leaf
loss from exposed shoots than from shaded shoots. Contrary to a widely hel
d view, there was no temperature dependence of leaf loss in wineberry at th
e whole-tree scale. However, the difference in proportional leaf loss betwe
en exposed and shaded shoots decreased with increasing temperature, driven
by an increase in leaf loss from shaded shoots at warm sites. Causes of the
se patterns may be elucidated by investigations of shoot-level phenology an
d leaf responses to winter photoinhibition.