Upper Midwest Environmental Sciences Center

Table 6.  Percent frequency, abundance index (AI), cover, and standard errors of submersed and rooted floating–leaf vegetation in Pool 4, Upper Mississippi River System, 1999.
Vegetation - Stratified Random Sampling 2000

Table 6.  Percent frequency, abundance index (AI), cover, and standard errors of submersed and rooted floating-leaf vegetation in La Grange Pool, Illinois River, 2000.

Common name
(Scientific name)
Contiguous
backwater

n = 100
Isolated
backwater

n = 138
Lake
n = 57
Freq
AI
Freq
AI
Freq
AI
bladderwort, common (Utricularia macrorhiza)
-
-
-
-
3.5 ± 2.5
0.5 ± 0.4
chara (Chara spp.)
-
-
-
-
3.5 ± 2.5
0.4 ± 0.3
coontail (Ceratophyllum demersum)
-
-
-
-
28.1 ± 6.0
7.0 ± 2.5
pondweed, horned (Zannichellia palustris)
-
-
-
-
1.8 ± 1.8
0.2 ± 0.2
pondweed, sago (Potamogeton pectinatus)
-
-
-
-
8.8 ± 3.8
0.7 ± 0.3
watermilfoil, Eurasian, (Myriophyllum spicatum)
-
-
-
-
63.2 ± 6.4
18.6 ± 3.0
watermilfoil, northern (M. sibiricum)
-
-
-
-
45.6 ± 6.7
9.0 ± 1.6
waternymph, brittle (Najas minor)
-
-
-
-
3.5 ± 2.5
0.3 ± 0.2
waternymph, southern (N. guadalupensis)
-
-
-
-
1.8 ± 1.8
0.1 ± 0.1

all submersed species
-
-
-
-
80.7 ± 5.3
26.8 ± 3.4
 
Freq
Cover
Freq
Cover
Freq
Cover
lotus, American (Nelumbo lutea)
1.0 ± 1.0
0.3 ± 0.3
9.4 ± 2.5
0.9 ± 0.2
22.8 ± 5.6
8.9 ± 2.6
primrose-willow (Ludwigia spp.)
-
-
-
-
1.8 ± 1.8
0.5 ± 0.5
waterlily, white (Nymphaea odorata)
-
-
-
-
14.0 ± 4.6
6.3 ± 2.6

all rooted floating–leaf species
1.0 ± 1.0
0.3 ± 0.3
9.4 ± 2.5
0.9 ± 0.2
33.3 ± 6.3
17.0 ± 3.7

Table 6.
Continued.

Common name
(Scientific name)
Main channel
border
n = 80
Secondary
channel

n = 50
La Grange
Pool*
n = 368
Freq
AI
Freq
AI
Freq
AI
bladderwort, common (Utricularia macrorhiza)
-
-
-
-
-
-
chara (Chara spp.)
-
-
-
-
-
-
coontail (Ceratophyllum demersum)
-
-
-
-
-
-
pondweed, horned(Zannichellia palustris)
-
-
-
-
-
-
pondweed, sago (Potamogeton pectinatus)
-
-
-
-
-
-
watermilfoil, Eurasian, (Myriophyllum spicatum)
-
-
-
-
-
-
watermilfoil, northern (M. sibiricum)
-
-
-
-
-
-
waternymph, brittle (Najas minor)
-
-
-
-
-
-
waternymph, southern (N. guadalupensis)
-
-
-
-
-
-

all submersed species
-
-
-
-
-
-
 
Freq
Cover
Freq
Cover
Freq
Cover
lotus, American (Nelumbo lutea)
-
-
-
-
6.0 ± 1.5
0.7 ± 0.2
primrose-willow (Ludwigia spp.)
-
-
-
-
-
-
waterlily, white (Nymphaea odorata)
-
-
-
-
-
-

all rooted floating–leaf species
-
-
-
-
6.0 ± 1.5
0.7 ± 0.2

*Lakes are not influenced by the Illinois River and, therefore, were not included in La Grange Pool percent frequency and abundance index.

Page Last Modified: April 17, 2018