Chapter 9 . Macroinvertebrate and Stream Habitat Relationships
183
9.4
Results and Discussion
As detailed below selected results of input-output relationships discovered by the
sensitivity analyses are discussed that are either complementary or contradictory
to existing theories on the ecology of stream macroinvertebrates.
9.4.1
Elucidation of Hypothetical Relationships
Cladocera (water flea) is known to be actively swimming zooplankton that prefers
slow flowing water at reasonable depth. Such conditions would typically occur in
streams that tend towards high order down land streams at low altitudes with large
channel widths when increasing water depth would correspond with a slightly
decreasing flow velocity. The sensitivity curve in Figure 9.3c clearly indicates that
the upper range of depths from 0.2 to 1.2 m favors Cladocera .
.... D. magna; McMahon 1965
AD. magna; Kersting u.v.d. Leeuw 1976
12
a
os
~
"" '"
004
Q2
0
::;J~A
!
...
.... I
I
I
I
......L......
I
I
I
10
20
30
40
5
10
15
20
25
30
35
TemperatureC
1.2
0.8
~
.g
0
0.4
D.2
0
0.5
1.5
Water Depth m
Figure 9.3. Relationships of Cladocera with a) water temperature and c) water
depth as discovered by sensitivity analysis. b) Physiological activity of Daphnia in
relation to water temperature as summarized by Lampert and Sommer (1997).
183
9.4
Results and Discussion
As detailed below selected results of input-output relationships discovered by the
sensitivity analyses are discussed that are either complementary or contradictory
to existing theories on the ecology of stream macroinvertebrates.
9.4.1
Elucidation of Hypothetical Relationships
Cladocera (water flea) is known to be actively swimming zooplankton that prefers
slow flowing water at reasonable depth. Such conditions would typically occur in
streams that tend towards high order down land streams at low altitudes with large
channel widths when increasing water depth would correspond with a slightly
decreasing flow velocity. The sensitivity curve in Figure 9.3c clearly indicates that
the upper range of depths from 0.2 to 1.2 m favors Cladocera .
.... D. magna; McMahon 1965
AD. magna; Kersting u.v.d. Leeuw 1976
12
a
os
~
"" '"
004
Q2
0
::;J~A
!
...
.... I
I
I
I
......L......
I
I
I
10
20
30
40
5
10
15
20
25
30
35
TemperatureC
1.2
0.8
~
.g
0
0.4
D.2
0
0.5
1.5
Water Depth m
Figure 9.3. Relationships of Cladocera with a) water temperature and c) water
depth as discovered by sensitivity analysis. b) Physiological activity of Daphnia in
relation to water temperature as summarized by Lampert and Sommer (1997).