© 1990 Heron Publishing—Victoria, Canada
Influence of female cones on the vegetative growth of Pinus contorta trees
J. McP. Dick (1), R. R. B. Leakey (1) and P. G. Jarvis (2)
1. Institute of Terrestrial Ecology, Bush Estate, Penicuik, Midlothian EH26 0QB, Scotland / 2. Department of Forestry and Natural Resources, Edinburgh University, Mayfield Road, Edinburgh EH9 3JU, Scotland / Received September 6, 1989
Summary
Branches of Pinus contorta Dougl. bearing two-year-old female cones initiated fewer lateral buds than vegetative branches. However, the number of lateral
shoots that differentiated and grew was not reduced on female cone-bearing branches. Neither the number nor the weight of
female cones influenced the
length of the terminal shoot. The total length of all lateral shoots was positively associated with the weight of two-year-old
female cones. Branch units with two-year-old female cones produced significantly more total dry weight in the current year
than vegetative branch units. There was, however, no significant reduction in the dry weight of terminal and lateral shoots.
Branches bearing female cones allocated between 17 and 45% of the current year’s dry weight to two-year-old cones and between
1 and 5% was allocated to one-year-old female cones. Female cones therefore apparently do not reduce the photosynthetic potential
of trees. The influence of female cones compared with male cones on the growth of trees is discussed.
