Ecological Archives A025-013-A4

Trevor C. Lantz, Steve V. Kokeli, and Robert H. Fraser. 2015. Ecological recovery in an Arctic delta following widespread saline incursion. Ecological Applications 25:170185. http://dx.doi.org/10.1890/14-0239.1

Appendix D. Results of the SIMPER analysis comparing plant community composition at impacted and unimpacted sites in the outer Mackenzie delta.

Table D1. Results of the SIMPER analysis comparing plant community composition at impacted and unimpacted site in the outer Mackenzie delta. The table shows the top four species (or species groups) that make the greatest contribution to the between-group Bray-Curtis dissimilarity for comparisons of interest. The mean cover (untransformed) of each species at the site types being compared is shown in the third and fourth columns.

Site 1 Site 2 Species / Group %Cover Sitetype 1 %Cover Sitetype 2 Cumulative Dissimilarity (%)

Unimpacted

Impacted

Moss

65.25

0.18

27.65

Dwarf Shrub

Dwarf Shrub 2007

Salix lanata

24.13

0

47.56

 

 

Equisetum variegatum

16.88

1.63

63.82

Percent Dissimilarity

= 93.72

Salix spp. (dead)

0

8.09

77.73

Unimpacted

Impacted

Moss

65.25

3.09

19.22

Dwarf Shrub

Dwarf Shrub 2010

Salix lanata

24.13

0

38.08

 

 

Equisetum variegatum

16.88

1.55

52.74

Percent Dissimilarity

=82.39

Salix spp. (dead)

0

7.36

63.98

Unimpacted

Impacted

Salix spp. (dead)

0.6

19.64

20.24

Graminoid

Graminoid 2007

Moss

32.5

3

37.69

 

 

Salix lanata

17.02

13.43

53.15

Percent Dissimilarity

=60.55

Carex aquatilis

30.32

27.71

65.85

Unimpacted

Impacted

Moss

32.5

1.79

23.39

Graminoid

Graminoid 2010

Salix lanata

17.02

14.14

41.18

 

 

Carex aquatilis

30.32

32.14

53.53

Percent Dissimilarity

=56.91

Equisetum variegatum

2.22

1.79

61.92

Unimpacted

Impacted

Moss

34.08

5.35

14.79

Upright Shrub

Upright Shrub 2007

Salix lanata

42.54

21.35

29.56

 

 

Salix spp. (dead)

1.36

22.30

43.38

Percent Dissimilarity

=74.7

Carex aquatilis

14.46

1.32

53.98

Unimpacted

Impacted

Moss

34.08

6.70

14.54

Upright Shrub

Upright Shrub 2010

Salix lanata

42.54

23.51

28.80

 

 

Carex aquatilis

14.46

1.43

39.12

Percent Dissimilarity

=71.3

Equisetum arvense

6.85

4.50

46.30

Impacted

Impacted

Moss

0.18

3.09

21.13

Dwarf Shrub 2007

Dwarf Shrub 2010

Melandrium apetalum

0

2.72

40.89

 

 

Salix spp. (dead)

8.09

7.36

56.73

Percent Dissimilarity

=56.82

Festuca richardsonii

0.82

2.18

71.85

Impacted

Impacted

Salix spp. (dead)

19.64

1.14

18.87

Graminoid 2007

Graminoid 2010

Carex aquatilis

27.71

32.14

32.77

 

 

Salix lanata

13.43

14.14

46.15

Percent Dissimilarity

=65.0

Moss

3

1.79

54.62

Impacted

Impacted

Salix spp. (dead)

22.30

8.50

13.75

Upright Shrub 2007

Upright Shrub 2010

Salix lanata

21.35

23.51

25.95

 

 

Festuca richardsonii

4.65

10.14

35.19

Percent Dissimilarity

=72.19

Hedysarum alpinum

7.60

7.22

43.76


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