Fauna & habitat: The effect of structural complexity on large mammal occurrence in revegetation

a woodland remnant in South Australia (Ward & Paton
2007) and over 500 plants per hectare in remnant forest and
woodland in southern New South Wales (March & Watson
2007). In general, the impact of mistletoe on a host depends
on the level of infestation (Reid & Yan 2000). Trees of two
species heavily parasitized by Box Mistletoe (i.e. mistletoe
comprising up to 90% of total foliage biomass) in northern
New South Wales, Australia, experienced reductions in
growth and in some cases mortality (Reid et al. 1994).
Tree species differ in their susceptibility to mistletoe par
asitism. Yellow Box (Eucalyptus melliodora (A. Cunn. Ex
Shauer)), for example, is a preferred host of Box Mistletoe
and individual trees may support large numbers of mistle
toes (i.e. over 250) (Reid & Yan 2000). In this study, levels
of mistletoe parasitism on Grey Box were substantially
lower (up to 10 plants per tree).
Although mistletoe parasitism can clearly be debilitating
for trees in some situations in agricultural landscapes, it is
not a problem for all species. Here, Box Mistletoe and a
widespread host, Grey Box, co-exist across a large region
with little evidence of detrimental impact on the host spe
cies. Greater understanding is required of the factors that
influence variation in the consequences of mistletoe parasit
ism for tree health between host species.
Finally, mistletoe parasitism is only one of a suite of fac
tors potentially affecting tree health in rural environments:
salinity, water stress and soil compaction may also be
involved. Rather, there is growing evidence of the benefits
of mistletoe in the landscape as these plants provide food
sources, nest sites or other habitat resources to a wide range
of native fauna (Watson 2001)