Misc 06 Regrowth
I came across this forest that had recently been backburned ready for the hot summer ahead. Nature is amazing in how it allows the trees to regenerate.
Adaptations for survival
Whether mature trees are killed or only have their leaves burnt, fire disturbance lets in light and
creates spaces for new growth. Fires usually occur in late summer, so seeds take advantage of
warm soils and Tasmania’s seasonal pattern of autumn and winter rains, to germinate well and get
a good growth start.
Adaptations for survival in individual eucalypts, especially those of drier forests such as the
peppermints and white gums, relate to features that allow them to live through fire. These include:
• lignotubers - swellings that develop at ground level in young eucalypts
and where food is stored, allowing new growth to sprout if the tree is
damaged. This can be seen even in young seedlings. Lignotubers
contain a mass of hidden buds. When the seedling, sapling or tree
is damaged by fire or grazing, new shoots rapidly grow from the
lignotubers enabling the plant to survive.
• an extensive root system which is made even more efficient by mycorrhizal associations, a
partnership between tree roots and a fungus, which enhances the tree’s absorption of water and
nutrients, especially phosphorus.
• epicormic buds on the tree’s branches and trunk which sprout when
triggered by stress, such as wildfire, which can severely damage the
crown. These buds, in the outer sapwood, are protected from fire
damage by the tree’s bark. They quickly sprout if a eucalypt looses its
crown. The new shoots (epicormic shoots) produce green foliage that
enables the tree to survive.
• Hard woody capsules that protect seeds high in the canopy where heat may be intense but
lasts for a very short time as the oil-rich leaves burn rapidly.