Environmental Engineering Reference
In-Depth Information
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Native
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Figure 15.9.
Surface litter masses (grams per square metre) of land rehabilitated with
Eucalyptus tetradonta forest at Gove (top panel) and E. marginata (Jarrah) forest at
Boddington (bottom panel) and comparative litter masses on unmined (native) forest
soil. Bars
ΒΌ
standard error of the mean (after Tibbett
2008
).
Stocks of litter on the forest floor are typically greater in restored sites than
native, unmined forest sites. Litter accumulation has been reported as being
almost four times greater than the surrounding Jarrah forest (Ward & Koch
1996
). Litter masses that accumulated at two contrasting bauxite mines, one
from the northern forests and the other in Western Australia, are both greater
in the restored than the native forests after around 15 years (
Fig. 15.9
). In the
western Jarrah forests, litter accumulation matched the native systems in only
10 years, while in the northern forests, this took a little longer, at 14 years. At
the now closed Jarrahdale mine site (Western Australia) the amount of carbon
held in the litter layer increased by 50% between 8-year-old and 15-year-old
rehabilitated sites (Sawada
1999
). This time frame is in keeping with the
natural senescence of many of the reseeding, short-lived Acacia species that
tend to dominate the canopy of the rehabilitated forest until this time. At Gove,
