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tree_ftree_f Tables

Table 5. Percent frequency of occurrence and abundance index or percent cover of sago pondweed (Stuckenia pectinatus [L.] Boerner; submersed), American lotus (Nelumbo lutea Willd.; rooted, floating–leaf), and broadleaf arrowhead (Sagittaria latifolia Willd.; emergent) by year and study reach, weighted by the areas of the aquatic strata (n = number of sites, Frq = percent frequency of occurrence, SE = standard error, AI = abundance index, Cov = percent cover). In 1998, sites were selected from depths less than or equal to 3 m.  After 1998, the criteria was changed to less than or equal to 2.5 m; therefore, any sites between 2.5 and 3 m were dropped from the 1998 analysis for comparison purposes.

Pool 4
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
506
1998
20.6
1.8
2.4
0.2
5.0
1.0
2.9
0.6
2.8
0.7
1.1
0.3
549
1999
15.8
1.6
2.1
0.2
1.9
0.6
0.5
0.2
3.4
0.8
1.0
0.3
631
2000
13.4
1.4
1.4
0.2
1.1
0.4
0.3
0.1
3.5
0.7
1.1
0.3
646
2001
11.5
1.3
1.4
0.2
1.1
0.4
0.4
0.2
5.2
0.9
1.8
0.4
630
2002
11.2
1.3
1.3
0.2
1.7
0.5
0.3
0.1
3.9
0.8
1.5
0.4
–
2003a
–
–
–
–
–
–
–
–
–
–
–
–
643
2004
8.3
1.1
1.0
0.1
2.6
0.6
0.8
0.2
5.7
0.9
2.7
0.5
446
2005
7.5
1.3
1.0
0.2
4.2
1.0
1.7
0.5
3.1
0.8
1.0
0.3
441
2006
13.4
1.6
1.9
0.3
6.2
1.2
2.7
0.6
6.6
1.2
3.2
0.7
438
2007
11.6
1.5
1.3
0.2
4.6
1.0
1.8
0.5
4.9
1.0
2.0
0.5
aPoolwide estimates were not calculated because no data were collected for the isolated backwater and Lake Pepin strata.

 

Upper Pool 4a
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
187
1998
21.5
3.0
2.5
0.4
0.0
0.0
0.0
0.0
0.6
0.6
0.2
0.2
213
1999
17.8
2.6
2.3
0.4
0.0
0.0
0.0
0.0
2.9
1.2
1.0
0.5
245
2000
13.0
2.2
1.2
0.2
0.0
0.0
0.0
0.0
1.0
0.7
0.3
0.2
245
2001
4.5
1.3
0.4
0.1
0.0
0.0
0.0
0.0
2.1
0.9
0.6
0.4
245
2002
9.1
1.8
0.9
0.2
0.0
0.0
0.0
0.0
1.1
0.7
0.5
0.4
–
2003a
–
–
–
–
–
–
–
–
–
–
–
–
251
2004
6.8
1.6
0.9
0.2
0.0
0.0
0.0
0.0
1.0
0.6
0.2
0.1
199
2005
7.8
1.9
0.9
0.2
0.0
0.0
0.0
0.0
1.9
1.0
0.4
0.2
200
2006
13.2
2.4
1.8
0.3
0.0
0.0
0.0
0.0
3.1
1.2
1.1
0.6
198
2007
14.6
2.5
1.5
0.3
0.0
0.0
0.0
0.0
4.1
1.4
2.2
0.9
aAnalysis was not completed because no data were collected for the isolated backwater and Lake Pepin strata.

 

Lower Pool 4a
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
288
1998
16.1
2.2
1.8
0.3
9.3
1.7
5.3
1.1
4.5
1.2
1.9
0.6
302
1999
9.8
1.7
1.3
0.3
3.5
1.1
0.9
0.3
3.9
1.1
1.0
0.4
354
2000
11.3
1.7
1.2
0.2
2.1
0.8
0.6
0.2
4.9
1.1
1.7
0.4
351
2001
13.6
1.8
1.6
0.2
2.1
0.8
0.7
0.3
7.1
1.4
2.5
0.6
355
2002
8.6
1.5
0.9
0.2
3.1
0.9
0.6
0.2
5.8
1.2
2.1
0.6
–
2003a
–
–
–
–
–
–
–
–
–
–
–
–
360
2004
7.4
1.4
0.8
0.2
4.8
1.1
1.5
0.4
8.6
1.5
4.5
0.9
227
2005
5.4
1.5
0.8
0.3
7.8
1.8
3.2
0.9
3.5
1.2
1.4
0.6
230
2006
9.4
1.9
1.3
0.3
11.6
2.1
5.0
1.1
9.1
1.9
5.0
1.3
230
2007
8.5
1.9
1.0
0.2
8.5
1.8
3.3
0.9
3.4
1.2
0.7
0.2
aAnalysis was not completed because no data were collected for the isolated backwater and Lake Pepin strata.

 

Pool 8
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
516
1998
18.8
1.7
2.5
0.3
7.5
1.2
4.4
0.8
5.3
1.0
3.1
0.6
595
1999
20.4
1.7
2.6
0.2
6.6
1.0
3.5
0.6
9.0
1.2
5.2
0.8
649
2000
13.9
1.4
1.5
0.2
5.4
0.9
1.9
0.4
4.8
0.8
2.5
0.5
670
2001
17.3
1.5
2.2
0.2
5.4
0.9
1.4
0.3
6.0
0.9
2.0
0.4
644
2002
14.5
1.4
1.6
0.2
6.9
1.0
2.1
0.4
8.2
1.1
4.1
0.7
649
2003
13.5
1.3
1.5
0.2
7.4
1.0
3.4
0.6
10.0
1.2
5.6
0.8
649
2004
16.7
1.5
2.0
0.2
8.2
1.1
3.8
0.6
9.3
1.1
4.3
0.6
450
2005
9.1
1.4
1.0
0.2
10.0
1.4
4.5
0.8
12.4
1.6
5.5
0.8
444
2006
17.1
1.8
1.8
0.2
12.2
1.6
6.5
1.0
9.4
1.4
6.6
1.1
448
2007
18.2
1.8
2.1
0.2
13.3
1.6
6.7
1.0

14.1
1.7
8.6
1.2

 

Pool 13
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
531
1998
22.0
1.8
2.6
0.2
15.9
1.6
9.1
1.1
2.7
0.7
1.6
0.5
550
1999
25.0
1.9
3.6
0.3
18.3
1.7
10.2
1.1
3.9
0.8
1.5
0.4
578
2000
21.5
1.7
2.9
0.3
18.1
1.6
9.1
1.0
3.6
0.8
2.2
0.5
606
2001
21.7
1.7
3.4
0.3
21.2
1.7
11.2
1.1
5.4
0.9
3.2
0.6
579
2002
22.8
1.8
3.2
0.3
21.3
1.7
8.6
0.9
4.5
0.9
2.9
0.6
580
2003
18.7
1.6
2.7
0.3
22.8
1.7
9.9
1.0
6.2
1.0
3.7
0.7
648
2004
20.8
1.6
2.8
0.2
22.4
1.6
8.4
0.8
6.2
0.9
3.0
0.5
450
2005
22.1
2.0
3.2
0.3
21.6
1.9
9.1
1.0
4.0
0.9
2.5
0.6
450
2006
22.6
2.0
2.9
0.3
25.2
2.1
13.0
1.3
7.2
1.2
4.9
1.0
444
2007
22.3
2.0
2.7
0.3
22.4
2.0
12.1
1.3
7.6
1.3
4.6
0.9

 

Pool 26, alla
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
519
1998
5.6
1.0
1.3
0.3
2.7
0.7
0.8
0.2
0.2
0.2
<0.1
<0.1
647
1999
0.6
0.3
<0.1
<0.1
1.5
0.5
0.7
0.2
0.8
0.3
0.2
0.1
392
2000
4.3
1.0
0.8
0.2
2.5
0.8
0.6
0.2
0.3
0.3
0.1
0.1
413
2001
0.8
0.4
0.1
0.1
3.3
0.9
1.8
0.5
0.0
0.0
0.0
0.0
417
2002
1.6
0.6
0.2
0.1
2.5
0.8
1.3
0.5
1.5
0.6
0.6
0.2
420
2003b
7.1
1.3
1.2
0.2
4.9
1.1
1.7
0.5
0.9
0.5
0.4
0.2
550
2004
0.0
0.0
0.0
0.0
1.3
0.5
0.4
0.2
1.0
0.4
0.4
0.2
aAnalysis includes Pool 26 of the Mississippi River and lower Alton Pool of the Illinois River.
bData were provided by the Illinois Natural History Survey based on a grant from the National Great Rivers Research and Education Center.

 

Pool 26, MRa
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
312
1998
0.0
0.0
0.0
0.0
0.2
0.2
0.1
0.1
0.4
0.3
0.1
0.1
437
1999
0.1
0.1
<0.1
<0.1
1.1
0.5
0.3
0.1
1.4
0.6
0.4
0.2
262
2000
0.0
0.0
0.0
0.0
0.9
0.6
0.2
0.1
0.5
0.4
0.3
0.2
279
2001
0.0
0.0
0.0
0.0
0.3
0.3
0.1
0.1
0.0
0.0
0.0
0.0
215
2002
0.2
0.3
<0.1
<0.1
0.4
0.5
0.3
0.3
2.1
0.9
0.6
0.3
280
2003b
0.0
0.0
0.0
0.0
0.8
0.5
0.3
0.2
1.5
0.7
0.7
0.4
362
2004
0.0
0.0
0.0
0.0
1.8
0.7
0.6
0.3
1.7
0.7
0.7
0.3
aPool 26, Mississippi River
bData were provided by the Illinois Natural History Survey based on a grant from the National Great Rivers Research and Education Center.

 

Pool 26, ILa
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
207
1998
13.6
2.4
3.1
0.6
6.3
1.7
1.7
0.5
0.0
0.0
0.0
0.0
210
1999
1.4
0.8
0.1
0.1
2.1
1.0
1.2
0.6
0.0
0.0
0.0
0.0
135
2000
9.7
2.6
1.8
0.6
4.4
1.8
1.1
0.5
0.0
0.0
0.0
0.0
134
2001
1.8
1.2
0.3
0.2
7.1
2.2
3.9
1.3
0.0
0.0
0.0
0.0
140
2002
3.4
1.5
0.3
0.2
5.2
2.1
2.8
1.4
0.9
0.9
0.5
0.5
140
2003b
16.0
3.1
2.6
0.6
10.1
2.6
3.4
1.2
0.0
0.0
0.0
0.0
188
2004
0.0
0.0
0.0
0.0
0.6
0.6
0.1
0.1
0.0
0.0
0.0
0.0
aLower Alton Pool, Illinois River
bData were provided by the Illinois Natural History Survey based on a grant from the National Great Rivers Research and Education Center.

 

La Grange Poola
Year
Sago pondweed
American lotus
Broad-leaf arrowhead
n
 
Frq
± SE
AI
± SE
Frq
± SE
Cov
± SE
Frq
± SE
Cov
± SE
464
1998
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
538
1999
0.0
0.0
0.0
0.0
0.5
0.3
0.1
0.1
0.0
0.0
0.0
0.0
368
2000
0.0
0.0
0.0
0.0
6.0
1.2
1.2
0.3
0.0
0.0
0.0
0.0
357
2001
0.0
0.0
0.0
0.0
0.3
0.3
0.2
0.2
0.0
0.0
0.0
0.0
369
2002
0.0
0.0
0.0
0.0
1.9
0.7
04
0.1
0.4
0.3
0.2
0.1