Growith of heath vegetation. IV. Effects of temperature on growth of Banksia ornata, B.serrata and B. serratifolia

Abstract

Established seedlings of three closely related Banksia species (B. ornata, B. serrata and B. serratifolia), with different distributions in southern and eastern Australia, were grown under different day/night temperature regimes in a phytotron for 20 weeks. Results of measurements of shoot elongation and plant productivity show that plants of B. ornata, grown from seed collected in south-eastern South Australia, have a lower temperature optimum for growth than plants of the other two species, which were grown from seed collected at warmer sites in central New South Wales and southern Queensland respectively. This result suggests that in the predominantly winter rainfall areas of southern Australia B. ornata is not necessarily a 'relict' species with a growth pattern typical of a more tropical climate with predominantly summer rainfall.