Geoscience Reference
In-Depth Information
Table 15.1
Representation of level one environments (n
=
20) in high value sites selected using national and regional
rankings of conservation priority. Additional columns indicate the percentage of the total network occupied by each
river environment, its average condition, and its representation in planning units (PLU) already having 80% or more of
their extent under formal protection. River environments having greater than 20% representation in high value sites
are shown in bold.
Percentage of
total network
Average
condition
Percentage in
protected PLU
Percentage in
high value sites
River Environment
Lowland rivers and
A
21.86
0.253
0.70
4.41
streams
B
0.37
0.345
17.37
38.89
C
44.07
0.407
15.10
7.11
D
4.38
0.302
2.38
4.79
E
0.14
0.134
1.12
23.06
F
0.12
0.324
6.26
21.53
Mid-elevation rivers and
G
10.45
0.405
19.94
7.71
streams
H
7.27
0.698
43.54
9.16
I
0.37
0.478
73.83
14.08
J
4.20
0.746
91.71
11.38
K
0.08
0.735
81.53
28.06
L
0.16
0.835
80.17
30.70
Glacial
M
0.02
0.381
35.40
25.52
High elevation rivers and
N
3.59
0.876
57.08
19.83
streams
O
1.09
0.902
94.51
16.03
P
0.86
0.879
76.01
13.96
Q
0.36
0.979
65.78
21.74
R
0.01
0.988
100.00
23.33
S
0.42
0.908
89.80
47.34
T
0.19
0.957
97.37
68.07
apparent in Plate 19d, with the inclusion of lower-
ranking planning units to facilitate management at
a whole-catchment level (lower left of Plate 19d),
and the amalgamation of sets of adjacent, highly
ranked small catchments to facilitate more efficient
management (right of Plate 19d).
While the selected high value sites provide
at least some protection across a full range of
ecosystem types (Table 15.1), the highest levels of
representation (20% or more) are provided mostly
for middle to high elevation environments (K-M,
Q-T) that are generally in very good condition
because of their existing legal protection. However,
note that these environments comprise only a
small proportion (1.2%) of the total river network.
High levels of representation are also provided for
three lowland environments (B, E, F) that are
again of limited extent, but which have suffered
moderate to high levels of degradation through
human activity. Lower levels of representation are
provided for those environments that predominate
at low- and middle-elevations (A, C, D, G, H), all
of which have been severely degraded by human
activity. Of these, A and D in particular have very
low levels of representation in existing reserves.
Although all biogeographic units contain at
least one high value site, there is also an
uneven spread of high value sites across units
(Table 15.2). The highest levels of representation
occur in the northern Northland unit, which
contains distinctive environments of restricted
geographic range. Elsewhere, the highest levels
of representation occur in the extensive montane
biogeographic units of the western and southern
