Dryandra Woodland - Department of Environment and Conservation ...

the south-west. This is despite Dryandra experiencing more severe fire weather conditions than the
main Jarrah forest belt. The primary reasons for the absence of large and devastating wildfires by
comparison with the main forest belt to the west are:
- the lower levels and discontinuous distribution of fuels;
- lower spotting distances due to the lack of fibrous-barked trees;
- the fragmented nature of Dryandra;
- the efficient fire detection and suppression system; and
- the reduced range of fire causes.
Fire Ecology
Burrows et al. (1987) considered the natural fire frequency at Dryandra to be relatively infrequent
based on the following factors:
- the rate of litter accumulation is variable, depending on canopy density, but is generally slow. For
most of Dryandra, litter fuel accumulation rates in the order of 0.5 tonnes per year over the first
ten years are typical. Rates slow even further as the canopy ages;
- the high proportion of fire sensitive species, ie. those species that are killed outright by full
foliage scorch;
- lack of epicormic crown recovery following fire; and
- the slow post-fire response of rootstock species.
Based on these factors, Burrows et al. (1987) considered that infrequent fires in the order of every
20-60 years may be important in maintaining a diversity of successional stages, but that fires less
than approximately 15 years apart could lead to a change in community floristics and structure, eg.
fire sensitive species with a long juvenile period could be eliminated.
While many fire management issues at Dryandra are similar to those elsewhere, complicating features
are:
- the difficulty of predicting fire effects when regeneration is relatively slow;
- the presence of many plant species 'vulnerable' to fire 6 ; and
- the highly fragmented nature of the Woodland.
In addition, many of the native fauna species for which Dryandra is noted have specific habitat
requirements that may be maintained through the appropriate management of fire. Dense thickets of
Rock Sheoak, and poisonous plants such as Gastrolobium microcarpum, provide protection for the
Woylie and Tammar, while hollow Wandoo logs are of particular importance to Numbats.
6 Plant species vulnerable to fire: vulnerability will depend on the stage of plant development and recent fire history. For
example, it is unlikely that a single fire will be catastrophic, but it may well render the population vulnerable to disturbance
for a period until reproductive capacity recovers.
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