NATIONAL PARK SERVICE The Impact of Three Exotic Plant Species on a Potomac Island

1 Comparison of combined control plot frequency.

2 Comparison of dry weight biomass dominance.

3 Comparison of square decimeter grid frequency dominance.

4 Comparison of cover dominance of Hedera helix.

5 Comparison of growth over time of dry-weight biomass.

6 Comparison of 1 year dry-weight biomass growth.

7 Comparison of 1.25 years dry-weight biomass growth.

8 Comparison of growth over time by frequency in upland H. helix.

9 Comparison of growth over time by frequency in natural understory L. japonica from a randomized block design experiment.

10 Comparison of growth over time by frequency in natural understory L. japonica from a completely randomized design experiment.

11 Comparison of 1 year of growth with control by frequency in flood-plain H. helix.

12 Comparison of 1.25 years of growth with control by frequency in flood-plain H. helix.

13 Comparison oft year with 1.25 years of growth by frequency in flood-plain H. helix.

14 Comparison of 1 year of growth with control by frequency in cleared understory L. japonica.

15 Comparison of 90 days of growth with control by frequency in cleared understory L. japonica.

16 Comparison of 1 year with 90 days of growth by frequency in cleared understory L. japonica.

17 Comparison of 1 year of growth by frequency in two habitats each for L. japonica and H. helix.

18 Comparison of 1.25 years of growth by frequency in natural understory L. japonica and two habitats each of H. helix.

19 Comparison of growth over time by area covered in upland H. helix.

20 Comparison of growth over time by area covered in flood-plain H. helix.

21 Comparison of 1 year of cover growth in two habitats of H. helix.

22 Comparison of 1.25 years of cover growth in two habitats of H. helix.

23 Description of flood and its effects as a result of Hurricane Agnes.

24 Influence of H. helix and other ground cover on mud deposition.

25 Flood survival of H. helix on the flood-plain in frequency/m².

26 Flood survival of H. helix on the flood-plain in square decimeters of cover/m².

27 Flood survival of woody plants, herbaceous plants, and comparisons of woody and herbaceous plants on the flood-plain.

28 Comparison of herbaceous and woody plants in upland H. helix weeded (treated) and unweeded (control).

29 Comparison of herbs, trees, and other woody plants in upland H. helix habitat.

30 Comparison of herbaceous and woody plants in natural understory L. japonica weeded (treated) and unweeded (control).

31 Comparison of herbs, trees, and other woody plants in natural understory L. japonica habitat.

32 Comparison of Podophyllum peltatum L. in the upland forest in exotic ground cover weeded (treated) and unweeded (control).

33 Comparison of herbaceous and woody plants in flood-plain H. helix weeded (treated) and unweeded (control).

34 Comparison of herbs, trees, and other woody plants in flood plain H. helix habitat.

35 Comparison of herbaceous and woody plants in cleared understory L. japonica weeded (treated) and unweeded (control).

36 Comparison of herbs, trees, and other woody plants in cleared understory L. japonica habitat.

37 Comparison of Parthenocissus quinquefolia in L. japonica natural and cleared understories.

38 Comparison of herbaceous plant increase in different habitats.

39 Comparison of woody plant increase in different habitats.

40 Comparison of tree increase in different habitats.

41 Comparison of woody plant (except trees) increase in different habitats.

42 Comparison of swamp-marsh transition, I. pseudacorus.

43 Comparison of swamp-marsh transition, Peltandra virginica.

44 Comparison of open marsh, Iris pseudacorus.

45 Comparison of open marsh, Peltandra virginica.

46 Comparison of Iris pseudacorus in swamp-marsh transition with that of open marsh.

47 Comparison of Peltandra virginica in swamp-marsh transition with that of open marsh.

48 Comparison of Iris pseudacorus and Peltandra virginica seed germination and survival.

49 The influence of Acorus calamus growth on Iris pseudacorus.

50 The influence of Iris pseudacorus growth on Acorus calamus.

51 Comparison of light by percent of open sunlight in forested habitats on 23 September, 1971.

52 Comparison of light by percent of open sunlight in forested habitats on 7 November, 1971.

53 Comparison of light by percent of open sunlight in forested habitats on 22 December, 1971.

54 Comparison of light by percent of open sunlight in forested habitats on 4 February, 1972.

55 Comparison of light by percent of open sunlight in forested habitats on 20 March, 1972.

56 Comparison of light by percent of open sunlight in forested habitats on 5 May, 1972.

57 Comparison of light by percent of open sunlight in forested habitats on 30 June, 1972.

58 Comparison of light by percent of open sunlight in forested habitats on 7 August, 1972.

59 Comparison of light by percent habitats on 7 November, 1971.

60 Comparison of light by percent of open sunlight in marsh habitats on 22 December, 1971.

61 Comparison of light by percent of open sunlight in marsh habitats on 4 February, 1972.

62 Comparison of light by percent of open sunlight in marsh habitats on 20 March, 1972.

63 Comparison of light by percent of open sunlight in marsh habitats on 5 May, 1972.

64 Comparison of light by percent of open sunlight in marsh habitats on 30 June, 1972.

65 Comparison of light by percent of open sunlight in marsh habitats on 7 August, 1972.

66 Comparison of light by percent of open sunlight in marsh habitats on 22 September, 1972.

67 Comparison of dry weight biomass for L. japonica.

68 Comparison of dry weight biomss for H. helix.

69 Comparison of chlorophyll for H. helix and L. japonica.

70 Comparison of dry weight H. helix leaf biomass.

71 Comparison of dry weight L. japonica leaf biomass.

72 Comparison of vigor of H. helix.

73 Comparison of vigor of L. japonica.

74 Controlled shade regression experiments on H. helix.

75 Controlled shade regression experiments on L. japonica.

76 Descriptive comparison of number of vegetational strata in different habitats.

77 Correlation of ground-layer heights in different but similar habitats.

78 The proportional number of strata present in each habitat.

79 Significant associations of one stratum with another.

80 Some associations of one woody stratum depth with another.

81 Discriminant function applied to differentiation of habitats with H. helix, L. japonica, and I. pseudacorus and similar habitats.

82 Relationship of living Ulmus americana overstory trees with H. helix and L. japonica.

83 Relationship of nonvigorous standing overstory trees (U. americana and all others) to H. helix and L. japonica vines.

84 Tabular analysis of exotic vines with vigor and tree type.

85 Relationship of overstory-size down trees (U. americana and all others) and type of fall (cut or natural) to Hedera helix and Lonicera japonica vines.

86 Percent of all down trees (Ulmus americana and all others) with various types of H. helix and L. japonica infestation.

87 Tabular analysis of exotic vines with type of tree fall and tree type.

88 Tabular analysis of exotic vines with tree fall type and tree type.

89 Comparison of elevations in the open marsh and swamp-marsh transition zone.

90 Comparison of topographic elevations in the open marsh and swamp-marsh transition zone.

91 Comparison of dry-weight biomass with percent of open sunlight and topographic elevation for I. pseudacorus.

92 Comparisons of presence or absence of Peltandra virginica in four microvegetation types.

93 Comparisons of soil color.

94 Comparisons of presence or absence of soil hardpan.

95 Comparison of total water discharge of the Potomac River.

96 Miscellaneous observations.

97 Comparison of three methods of determining dominance and rate of growth on H. helix, I. pseudacorus, and L. japonica.