DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY DR JEREMY BURGESS / SCIENCE PHOTO LIBRARY
Myrtle beech (Nothofagus cunninghamii) tree growing in the Otway Ranges, Victoria, Australia. This mature tree is exhibiting dieback of its large branches following an infection by myrtle wilt (Chalara australis). The tree is responding by producing epicormic shoots from still living lower parts of branches. Myrtle wilt is indigenous to Australia, and myrtle beech is the only natural host for the pathogen. It is a major cause of death of myrtle beech trees in cool temperate rainforests, especially in the Otway Ranges. The fungus gains entry to the tree through wounds, and can spread within groups of trees via roots that have grafted together. In mixed forests, a common cause of wounding is falling limbs of eucalyptus trees. Fortunately, loss of mature beech trees promotes the regeneration of their seedlings at forest floor level, due to increased light reaching the ground.
Model release not required. Property release not required.