Contrasting adaptation of two Eucalyptus subgenera is related to differences in respiratory metabolism

Abstract

1. The largest eucalypt subgenus Symphyomyrtus survives and grows better in diverse native and exotic environments than the second largest subgenus Monocalyptus. Previously postulated reasons for this difference; including differential resistance to native insect pests and dependence on specific ectomycorrhizal symbiotic associations with soil fungi, do not fully explain the marked adaptive differentiation. 2. This work shows that differences between the subgenera in survival and growth performance are related to respiratory parameters, we propose that effects of climatic temperature on respiratory metabolism result in Symphyomyrtus being more successful than Monocalyptus in adapting to diverse environments. This suggests a new paradigm for adaptation and evolution of eucalypts.