Environmental Engineering Reference
In-Depth Information
Box 4.1 Enhancing landscape processes: selecting species
for mine site revegetation
After a site in eastern Australia was mined for sand and
gravel, and then regraded with topsoil to reproduce a
landform comprised of low rolling rises and ponds, an
unknown restorationist undertook a project with a goal
to successfully restore self-sustaining vegetation on
this disturbed landscape. This restorationist selected
Casuarina and Eucalyptus plantation species to reveg-
etate the landform in a mixture simulating the relative
abundance and spatial distribution in reference sites.
We and the body responsible for restoration, who
invited Landscape Function Analysis to be deployed,
observed that the Casuarina species quickly estab-
lished and commenced dropping leaf litter within a
couple of years, forming a dense, interlocked surface
mat (Figure 4.3a), which resisted runoff and erosion.
The Eucalyptus species was slower to establish, per-
mitting a physical crust to develop on the soil surface
(Figure 4.3b), which readily shed rainfall. However,
after 5 years, the Eucalyptus steadily increased its
production of coarse woody litter (twigs, branches) so
that after 10 years areas with a mix of Casuarina and
Eucalyptus species formed an excellent ground cover
of litter (Figure 4.3c). The restorationist used Land-
scape Function Analysis monitoring methods (see
section 4.2.5) to measure indicators of runoff and soil
particle movement processes, and found that data
trends for these indicators were OK and that restora-
tion goals were being achieved (see Figure 4.1).
(a)
(b)
(c)
Figure 4.3 Litter on landscape surfaces after 2 years under: (a) Casuarina species, and (b) Eucalyptus species and (c) after 10
years under both species. (Photographs by David Tongway.)
In our experience, regardless of the magnitude of the
project, the selected and implemented design should
aim at restoring landscape processes such as improv-
ing the retention of water in eroded rangelands
(Box 4.2 ).
restoration tools and technologies have been applied,
using the Landscape Function Analysis procedures
described for this purpose (Figure 4.1, step 5a). Land-
scape Function Analysis has a number of abiotic
indicators which are very informative at this stage,
especially in defi ning the initial dysfunctional status of
the land. Newly restored landscapes may be vulnerable
to energetic storms early in their life; as a result, appro-
priate monitoring methods are needed to check that
restoration trends are progressing towards goals. Early
initiation of monitoring is also advantageous because
repairing minor defects early on is much simpler and
4.2.5 Monitoring and evaluating restoration
progress
Monitoring trends on how well landscape processes are
functioning should commence as soon as the selected
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