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summary: |
During June 1998 a very strong windstorm at the Snowy River
National Park near Mt Gelantipy caused severe damage to a stand
of Eucalyptus delegatensis. Little is known about the impact of
windthrow on E. delegatensis and subsequent seedling
recruitment. This study was undertaken 4.5 y later to examine (i)
windthrow damage to E. delegatensis and the understorey Acacia
dealbata, (ii) the influence of tree size on the pattern of tree
damage, (iii) the undergrowth in the windthrow area compared
with that in control plots, and (iv) species composition of the soilstored
seed-bank in windthrow and control plots.
We found that high winds toppled virtually all trees regardless of
size and species, damaging 99% of the E. delegatensis. In
windthrow plots there were 49 seedlings ha–1 of E. delegatensis
and 2210 ha–1 of A. dealbata. No E. delegatensis or A. dealbata
seedlings were recorded in the control plots. In the soil seed-bank
study five species were recovered from soil samples collected
from the control, and six from the windthrow-damaged sites. The
canopy species E. delegatensis recruited only from the windthrow
site. The exotic Rubus fruticosus was found to be colonising the
windthrow site, but was not present in the control site. Results
show that E. delegatensis recruitment is very poor in the damaged
area, and species colonising within that area are light demanding
or early succession species. It is proposed that seedling recruitment
in the windthrow sites be accelerated by burning the site and
broadcasting E. delegatensis seed, or transplanting seedlings.
Keywords: seedbeds; seedlings; regeneration; plant succession; plant
colonisation; wind damage; alpine ash; Eucalyptus delegatensis |