Ecological Archives E095-014-A2

Nicole L. Goebel, Christopher A. Edwards, Michael J. Follows, Jonathan P. Zehr. 2014. Modeled diversity effects on microbial ecosystem functions of primary production, nutrient uptake, and remineralization. Ecology 95:153–163. http://dx.doi.org/10.1890/13-0421.1

Appendix B. Simplified application and interpretation of diversity effects for two-member-ensemble calculations.

Analysis of two-member ensembles more effectively aids interpretation by illustrating diversity effects in simpler contexts compared to using the full 10-member polyculture. High, positive complementarity effects and nearly equal negative SEs occur in instances where a phytoplankton type with very low monoculture productivity shows a substantial increase in polyculture. CE values are exceedingly large when a PLP and DIA are paired (replicates #3, #7, and #11; Table B1), owing to very low PLP monoculture productivity and its large productivity boost resulting from increased availability of reduced nitrogen forms by the recycling of new production by DIA. This facilitation also occurs within SNP-DIA assemblages (replicates #1, #2, #5, and #13; Table B1), though the values are less dramatic because SNP monoculture yield is substantial, and overyielding is not as great as in the PLP case. For assemblages with identical functional types, such as two DIA (replicates #4, #12, #15; Table B1) and two PLP (replicates #8, #9, and #14; Table B1), net diversity effects are negligible and in cases negative. When two DIA compete, modest dominance of one occurs at the expense of another, whereas in an assemblage of two PLP, small selection and complementarity effects that cancel out result. The combination of two SNP (replicate #6; Table B1) leads to a modest net effect as complementarity resulting from nutrient remineralization and utilization numerically exceeds a smaller negative selection associated with competition (dominance).

Table B1. Experiment results for fifteen replicates of the two-member polyculture ensemble: Phytoplankton type and number, productivity (mg C·m-2·d-1) in monoculture and polyculture (spatially and temporally averaged, and vertically integrated), and calculated diversity effects of net, complementarity, selection, trait-dependent complementarity and dominance.

Replicate

Phytoplankton type

Phytoplankton number

Monoculture productivity (mg C·m-2·d-1)

Polyculture productivity (mg C·m-2·d-1)

Net effect

Complementarity

effect

Selection effect

Trait-dependent complementarity effect

Dominance effect

1

DIA

24

145.9

120.3

135.0

148.5

-13.4

-7.4

-6.1

1

SNP

47

98.3

136.8

-

-

-

-

-

2

SNP

39

92.0

131.7

145.7

159.7

-14.0

-8.0

-6.0

2

DIA

24

145.9

132.9

-

-

-

-

-

3

DIA

69

143.9

138.2

117.3

148437.9

-148320.6

-148248.7

-71.9

3

PLP

23

0.0

51.1

-

-

-

-

-

4

DIA

32

150.9

17.9

0.3

0.2

0.1

0.0

0.1

4

DIA

46

151.2

133.5

-

-

-

-

-

5

SNP

31

87.9

104.4

116.0

124.9

-8.9

-4.6

-4.3

5

DIA

24

145.9

128.5

-

-

-

-

-

6

SNP

39

92.0

67.9

7.9

9.1

-1.2

-0.1

-1.1

6

SNP

47

98.3

35.2

-

-

-

-

-

7

DIA

24

145.9

143.4

88.3

4655168.9

-4655080.6

-4655007.6

-72.9

7

PLP

77

0.0

17.8

-

-

-

-

-

8

PLP

23

0.025

0.008

0.012

0.754

-0.742

-0.729

-0.012

8

PLP

77

0.000

0.017

-

-

-

-

-

9

PLP

5

0.018

0.004

0.013

0.562

-0.549

-0.540

-0.009

9

PLP

77

0.0003

0.0177

-

-

-

-

-

10

SNP

39

92.0

89.5

47.0

6529.9

-6482.8

-6437.5

-45.4

10

PLP

23

0.025

3.515

-

-

-

-

-

11

DIA

69

143.9

141.6

87.4

4569296.7

-4569209.3

-4569137.4

-72.0

11

PLP

77

0.0003

17.7446

-

-

-

-

-

12

DIA

69

143.9

90.1

-0.3

0.6

-0.9

0.0

-0.9

12

DIA

32

150.9

57.0

-

-

-

-

-

13

DIA

69

143.9

121.8

135.3

147.2

-11.9

-6.5

-5.4

13

SNP

47

98.3

134.6

-

-

-

-

-

14

PLP

5

0.018

0.005

0.012

0.009

0.003

0.001

0.002

14

PLP

23

0.025

0.029

-

-

-

-

-

15

DIA

69

143.9

62.9

-0.3

-0.4

0.1

0.0

0.1

15

DIA

24

145.9

81.7

-

-

-

-

-


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