Royalties for RegionS Carbon Project - showcase

Eva species carbon x salinity
120%
Percent
100%
80%
60%
40%
20%
0%
Aamn
Anum
Cobe
Ecam
Elox
Ewan
Mthy
Munc
Mvim
0-99 100-199 200-299 300-399 400-499
Eca mS/m
Graph 1 - Carbon sequestered by each species
The species analysed
Nine species were sampled and
analysed on this property: Atriplex
amnicola (River saltbush), Atriplex
nummularia (Oldman saltbush),
Casuarina obesa (Swamp sheoak),
Eucalyptus camaldulensis (Red river
gum), Eucalyptus loxophleba subsp
lissophloia (York gum), Eucalyptus
wandoo (Wandoo), Melaleuca
thyoides (Salt lake honey myrtle),
Melaleuca uncinata (Broombush)
and Melaleuca viminea (Mohan).
The range of species provided a
great insight into how much carbon
could be sequestered by each in
varying levels of salinity.
Carbon sequestration
The amount of carbon sequestration
varied considerably depending
on the species and the severity of
the salinity. One species which did
stand out overall was Broombush
(Melaleuca uncinata). It was found
Measurement
age in years
Salinity (ECa in
mS/m)
mean
range
to sequester the highest amount of
carbon of all of the species tested.
However, on the most saline sites,
River saltbush (Atriplex amnicola)
was found to sequester the most
carbon.
Graph 1 shows
the amount
of carbon
each species
sequestered
in a range of
salinity levels.
Site
As the
salinity levels
increased,
the amount
of carbon which was sequestered
dropped. Table 1 shows that there
is a clear relationship between the
levels of salinity and the amount of
carbon sequestered.
Part of the study also looked at the
Australian Government’s carbon
estimation model FullCAM 3.55 and
compared these figures with the
Tree carbon (t CO 2
-e
/ha)
At
measure
age
Predicted
15 yrs
Predicted
30 yrs
actual figures recorded from the
project (Table 2). The difference
between the actual measured
figures and the government model
figures varied quite dramatically
at this site. At the other five
Site average
carbon
at time of
measurement
(t CO 2
-e/ha)
Site area (ha)
Site total
carbon
(t CO 2
-e)
Total site 16.4 56.84 1055
Extreme saline 11 25 275
Low saline 27 32 864
Predicted carbon
stocks (t CO2-e/
ha) from FullCAM
3.55
Trees
only
Trees and
Debris*
12.8 245 37-463 16.4 20.4 38.1 64.8 87.4
Table 2 - Comparing estimation with actual carbon
Table 1 - Relationship between salinity and carbon
sites trialled, only one other
overestimated dramatically, while
three overestimated, and one
underestimated.
One of the reasons why the FullCAM
3.55 model may have overestimated
at this site is because of the very
high levels of salinity. The model
doesn’t take this into consideration.
Also the debris at the site was
basically non-existent (potentially
due to the young age of the trees),
whereas the model will allow a
maximum of 35 per cent of the total
tree carbon to be used.
Royalties for Regions Carbon Project - Showcase 13