Does irrigation affect leaf phenology in deciduous and evergreen trees of the savannas of northern Australia?
Version of Record online: 28 JUL 2006
Australian Journal of Ecology
Volume 23, Issue 4, pages 329–339, August 1998
How to Cite
MYERS, B. A., WILLIAMS, R. J., FORDYCE, I., DUFF, G. A. and EAMUS, D. (1998), Does irrigation affect leaf phenology in deciduous and evergreen trees of the savannas of northern Australia?. Australian Journal of Ecology, 23: 329–339. doi: 10.1111/j.1442-9993.1998.tb00738.x
- Issue online: 28 JUL 2006
- Version of Record online: 28 JUL 2006
- Accepted for publication July 1997.
- soil water;
- wet-dry tropics
Abstract Soil moisture was augmented experimentally during two successive dry seasons and the intervening wet season in a humid tropical savanna in Darwin, northern Australia. Leaf phenology was monitored in four common tree species Termmalia ferdinandiana and Planchonia careya (both deciduous species), and Eucalyptus miniata and Eucalyptus tetrodonta (both evergreen species). Irrigation produced consistently significant effects in only T. ferdinandiana. In this species leaf-flush was significantly earlier, canopy decline and leaf-fall were significantly later and the attainment of full canopy was earlier in irrigated compared with non-irrigated trees. Litterfall, and the seasonal patterns of contraction and expansion of stems (a measure of stem water status or storage) were not significantly affected by irrigation in any species. Leaf longevity in the deciduous species was 6–8 months; some eucalypt leaves lived for approximately 1 year, but none lived longer than 18 months. Irrigation had relatively little effect on leaf longevity. While variation in soil moisture is a potentially important cue to both leaf-fall and leaf-flush, stem water status and climatic factors such as vapour pressure deficit may also be important climatic cues to phenological behaviour.