A.  Percent frequencies calculated using all areas of Lawrence Lake.

Year

1992

1993

1994

1995

1996

1997

1998

1999

2000

Number of sites sampled

398

435

407

386

417

402

441

428

405

All submersed vegetation

69.8

62.1

74.2

68.4

81.8

73.1

89.9

91.0

95.3

coontail

17.3

46.4

51.6

54.9

73.4

67.4

87.8

78.7

93.8

chara

Chara spp.

-

-

-

-

-

-

0.9

0.5

0.7

Canadian waterweed

Elodea canadensis

-

4.6

11.3

1.8

3.6

6.2

15.2

39.3

64.2

water stargrass

Heteranthera dubia

0.3

0.7

1.0

0.5

1.9

3.7

10.2

6.3

5.9

Eurasian watermilfoil

Myriophyllum spicatum

21.9

32.9

60.2

26.2

34.5

30.8

42.6

44.1

54.3

nodding waternymph

Najas flexilis

2.0

1.8

4.9

5.4

10.1

5.0

13.6

9.1

4.0

southern waternymph

N. guadalupensis

0.3

-

-

-

-

-

-

-

-

curly pondweed

Potamogeton crispus

36.4

12.0

7.1

6.5

14.6

10.9

21.8

6.1

9.4

leafy/small pondweed

P. foliosus/P. pusillus

-

0.5

2.9

5.4

20.4

14.7

13.8

7.7

8.4

longleaf pondweed

P. nodosus

-

0.9

0.7

0.8

1.4

0.7

0.9

0.9

1.2

sago pondweed

P. pectinatus

32.9

6.4

7.4

26.4

37.9

16.9

34.2

11.2

8.9

flatstem pondweed

P. zosteriformis

1.0

1.4

0.7

0.8

7.9

5.5

9.3

10.7

13.3

longbeak buttercup

Ranunculus longirostris

-

-

-

-

-

-

-

2.8

15.8

common bladderwort

Utricularia macrorhiza

0.3

0.7

1.2

1.0

3.8

2.7

13.4

1.6

7.9

wild celery

Vallisneria americana

0.3

-

0.2

0.3

0.2

0.2

0.5

0.9

0.5

All rooted floating leaf vegetation

56.8

56.1

52.6

51.6

60.7

57.5

58.7

47.7

59.5

American lotus

Nelumbo lutea

6.0

8.7

7.4

9.3

15.3

15.4

16.3

15.7

10.1

yellow pond-lily

Nuphar variegata

8.0

12.9

11.1

11.1

12.5

10.9

11.6

8.4

13.1

white water-lily

Nymphaea odorata

54.0

50.3

48.4

47.4

57.1

48.8

51.7

43.9

57.3

13

14

15

15

15

15

16

17

17

B.  Percent frequencies calculated using only areas of Lawrence Lake sampled during the 2001 drawdown.

Year

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

Number of sites sampled

339

359

347

340

351

354

378

348

346

318

All submersed vegetation

69.9

56.5

70.0

65.9

78.6

70.6

88.4

90.5

94.5

73.4

coontail

12.7

38.4

44.4

52.4

69.2

63.8

86.0

84.5

93.1

49.2

chara

Chara spp.

-

-

-

-

-

-

-

0.5

0.9

-

Canadian waterweed

Elodea canadensis

-

3.3

9.2

1.5

3.1

4.8

14.6

44.8

62.7

21.1

water stargrass

Heteranthera dubia

0.3

0.3

1.2

0.3

2.0

4.2

10.3

7.1

6.4

5.3

Eurasian watermilfoil

Myriophyllum spicatum

23.3

35.1

59.4

24.7

35.9

33.0

45.2

50.0

56.4

-

nodding waternymph

Najas flexilis

2.1

1.7

4.0

5.0

8.5

3.7

13.2

9.0

3.5

0.3

southern waternymph

N. guadalupensis

0.3

-

-

-

-

-

-

-

-

curly pondweed

Potamogeton crispus

38.6

12.8

5.5

5.9

15.1

10.2

25.7

7.6

9.8

25.6

leafy/small pondweed

P. foliosus/P. pusillus

-

-

0.6

4.1

16.8

10.5

11.9

7.6

6.6

5.1

longleaf pondweed

P. nodosus

-

0.3

0.6

0.9

1.1

0.6

1.1

1.1

1.4

-

sago pondweed

P. pectinatus

35.7

6.4

6.9

26.2

40.2

17.5

37.7

13.9

8.4

18.8

flatstem pondweed

P. zosteriformis

0.3

0.6

-

0.3

5.6

2.8

8.2

10.6

11.0

5.1

longbeak buttercup

Ranunculus longirostris

-

-

-

-

-

-

-

2.7

15.6

-

common bladderwort

Utricularia macrorhiza

-

0.3

-

0.3

2.0

2.0

5.8

0.3

2.9

0.3

wild celery

Vallisneria americana

0.3

-

0.3

0.3

0.3

0.3

0.5

1.2

0.6

0.3

All rooted floating leaf vegetation

51.6

49.3

45.8

47.6

53.8

52.0

51.9

53.4

53.5

56.5

American lotus

Nelumbo lutea

5.9

7.8

6.9

9.1

14.5

16.4

16.1

16.8

10.6

5.1

yellow pond-lily

Nuphar variegata

7.1

11.7

9.5

9.4

12.3

9.9

8.7

7.3

9.8

5.8

white water-lily

Nymphaea odorata

48.7

43.5

41.5

43.5

50.4

42.9

44.4

45.7

51.2

43.4

Total number of species recorded

12

13

13

15

15

15

15

17

17

13