Comparative Studies in Selected Species of Eucalyptus Used in Rehabilitation of the Northern Jarrah Forest, Western Australia. II. Wood and Leaf Anatomy

Abstract

Previous studies have established differences in water relations between the major dominant of the northern jarrah forest, Eucalyptus marginata, which transpires freely except under conditions of extreme drought, and potential replacement species which exhibit some measure of stomatal control. The anatomy of the water-conducting system of three indigenous species (Eucalyptus marginata, E. calophylla and E. wandoo) and four eastern Australian species (E. globulus, E. maculata, E. resinifera and E. saligna) is described with reference to their patterns of stomatal resistance and xylem pressure potential. Vessel and parenchyma distribution generally correlated with taxonomic affinities of the species. Groups based on wood anatomy had little in common with groupings based on eco-physiological behaviour but did tend to confirm the distinctive character of E. marginata. By using leaf anatomy, a third grouping of species was possible. E. globulus, E. maculata and E. wandoo are amphistomatous whereas E. calophylla, E. resinifera, E. saligna and E. marginata are hypostomatous. However, the major structural features associated with previously observed patterns of water relations appear related to differences in vessel size (particularly in E. wandoo) and the presence and size of the stomatal antechambers. The anatomical structures described here confirm the special way in which E. rnarginata responds to environmental factors, and thus emphasize the challenge of finding a substitute species that exhibits similar anatomical and physiological adaptations.