Eucalyptus regnans (Myrtaceae): A fire-sensitive eucalypt with a resprouter epicormic structure.
David A Waters1, Geoffrey E Burrows, John D I Harper
1Institute for Land, Water and Society, Charles Sturt University, Elizabeth Mitchell Drive, P.O. Box 789, Albury NSW 2640, Australia.
American Journal of Botany
|May 31, 2011
Summary
Eucalyptus regnans, a fire-sensitive eucalypt, possesses epicormic bud structures, contrary to previous assumptions. This species prioritizes rapid growth over vegetative fire survival mechanisms.
Area of Science:
- Botany
- Plant Physiology
- Ecology
Background:
- Understanding plant response to fire is crucial for ecological studies.
- Eucalypts typically exhibit epicormic resprouting for fire survival.
- Eucalyptus regnans is considered fire-sensitive, with limited resprouting capacity.
Purpose of the Study:
- To investigate the presence and structure of bud-forming meristems in Eucalyptus regnans.
- To determine if Eucalyptus regnans possesses epicormic bud structures despite its fire-sensitive nature.
- To understand the anatomical basis for Eucalyptus regnans' resprouting capabilities.
Main Methods:
- Anatomical examination of epicormic strands from bark and outer xylem.
- Analysis of samples from mature trees and saplings of Eucalyptus regnans.
- Microscopic observation of bud-forming structures and meristematic tissues.
Main Results:
- Epicormic bud-forming structures were identified in all examined Eucalyptus regnans samples.
- These structures consist of narrow, radially elongated meristematic cell strips.
- The bud-forming capacity extends from the outer xylem through to the outer bark.
Conclusions:
- Eucalyptus regnans possesses fire-adapted epicormic strands, indicating a shared evolutionary lineage with resprouting eucalypts.
- Despite having the structures for resprouting, Eucalyptus regnans appears to allocate resources towards rapid height growth.
- This resource allocation strategy may explain the species' fire sensitivity and reliance on obligate seeding.
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