Ecological Archives A025-080-A1

Jennifer L. Bufford and Orou G. Gaoue. 2015. Defoliation by pastoralists affects savanna tree seedling dynamics by limiting the facilitative role of canopy cover. Ecological Applications 25:13191329. http://dx.doi.org/10.1890/14-0953.1

Appendix A. Results from mixed effects models of seedling and sapling dynamics and AICc values used for model selection.

Table A1. Candidate models of Khaya senegalensis new seedling, seedling (<2 cm basal diameter), and sapling (>2 cm basal diameter) densities, in 12 populations in two regions under different harvest regimes. An interaction is indicated by ‘*’ and all terms included in the interaction were also included as individual terms. An estimate of total fruit produced per population per year (Fruit) was included only in models of newly recruited seedlings. Population and plot within population were included as random effects in all models. AICc values were calculated from models fit with maximum likelihood to compare fixed effects. New seedlings and seedlings were modelled with a negative binomial distribution (α = 0.6 and 7.3); sapling density was modeled with a Poisson distribution.

ID

Model

New Seedlings

Seedlings

Saplings

AICc

ΔAICc

AICc

ΔAICc

AICc

ΔAICc

1

Region*Harvest + Region*Woody + Region*Grass + Canopy + Burn + Fruit

947.1

10.0

1475.4

5.8

565.2

9.0

2

Region*Harvest + Region*Woody + Grass + Canopy + Burn + Fruit

945.0

7.9

1473.7

4.1

563.7

7.5

3

Region*Harvest + Region*Grass + Woody + Canopy + Burn + Fruit

948.2

11.0

1476.2

6.5

563.2

6.9

4

Region*Woody + Region*Grass + Harvest + Canopy + Burn + Fruit

945.0

7.9

1473.3

3.7

565.5

9.2

5

Region*Harvest + Woody + Grass + Canopy + Burn + Fruit

946.0

8.9

1474.6

4.9

561.8

5.5

6

Region*Harvest + Burn + Fruit

941.8

4.7

1474.3

4.7

556.3

0.0

7

Region*Woody + Harvest + Grass + Canopy + Burn + Fruit

942.9

5.8

1471.6

2.0

564.1

7.8

8

Region*Woody + Grass + Canopy + Burn + Fruit

941.6

4.4

1470.6

0.9

562.1

5.8

9

Region*Grass + Harvest + Woody + Canopy + Burn + Fruit

946.1

9.0

1474.2

4.5

563.4

7.1

10

Region*Grass + Woody + Canopy + Burn + Fruit

945.3

8.2

1473.3

3.6

561.3

5.1

11

Region + Harvest + Woody + Grass + Canopy + Burn + Fruit

944.0

6.9

1472.5

2.9

562.1

5.8

12

Region + Harvest + Woody + Grass + Canopy

NA

NA

1478.4

8.8

560.7

4.4

13

Region + Harvest + Burn + Fruit

939.9

2.7

1472.7

3.0

558.0

1.7

14

Harvest + Woody + Grass + Canopy + Burn + Fruit

942.4

5.3

1470.6

0.9

564.1

7.8

15

Region + Woody + Grass + Canopy + Burn + Fruit

943.2

6.0

1471.6

2.0

560.2

3.9

16

Woody + Grass + Canopy + Burn + Fruit

941.5

4.4

1469.7

0.0

562.0

5.7

17

Region + Harvest + Fruit

940.2

3.1

1477.8

8.2

556.5

0.3

18

Woody + Grass + Canopy + Fruit

940.8

3.7

1475.9

6.2

560.9

4.6

19

Burn + Fruit

938.3

1.2

1471.6

1.9

559.6

3.3

20

Fruit

939.2

2.0

NA

NA

NA

NA

21

Intercept Only

937.1

0.0

1477.2

7.5

558.2

1.9

 

Table A2. Candidate models of the relative growth rate (RGR) of seedlings and saplings of Khaya senegalensis from 12 populations in two regions under different harvest regimes. RGR was calculated as the relative change in basal diameter in a year. An interaction is indicated by ‘*’ and all terms included in the interaction were also included as individual terms. Population and plot within population were included as random effects. The models include heterogeneous variances by population. AICc was calculated from models fit with maximum likelihood to compare fixed effects.

ID

Model

Seedling RGR

Sapling RGR

AICc

ΔAICc

AICc

ΔAICc

1

Region*Harvest + Region*Woody + Region*Grass + Harvest*Year + Canopy + Burn

1168.1

4.4

-161.4

5.3

2

Region*Harvest + Harvest*Year + Woody + Grass + Canopy + Burn

1171.8

8.1

-165.8

0.9

3

Region*Harvest + Region*Woody + Grass + Canopy + Burn + Year

1170.1

6.4

-162.6

4.1

4

Region*Harvest + Region*Grass + Woody + Canopy + Burn + Year

1174.0

10.3

-163.3

3.3

5

Region*Woody + Region*Grass + Harvest + Canopy + Burn + Year

1167.6

3.9

-163.2

3.5

6

Region*Woody + Harvest*Year + Grass + Canopy + Burn

1167.5

3.8

-164.4

2.3

7

Region*Grass + Harvest*Year + Woody + Canopy + Burn

1169.4

5.8

-164.4

2.3

8

Region*Harvest + Woody + Grass + Canopy + Burn + Year

1174.3

10.6

-164.3

2.4

9

Region*Harvest + Burn + Year

1169.9

6.2

-157.2

9.5

10

Harvest*Year + Region + Woody + Grass + Canopy + Burn

1170.2

6.5

-166.7

0.0

11

Harvest*Year + Region + Burn

1165.5

1.8

-162.5

4.2

12

Region*Woody + Harvest + Grass + Canopy + Burn + Year

1168.0

4.3

-163.3

3.4

13

Region*Woody + Grass + Canopy + Burn + Year

1165.9

2.2

-164.5

2.2

14

Region*Grass + Harvest + Woody + Canopy + Burn + Year

1172.1

8.4

-164.7

2.0

15

Region*Grass + Woody + Canopy + Burn + Year

1170.0

6.3

-165.0

1.7

16

Region + Harvest + Woody + Grass + Canopy + Burn + Year

1172.2

8.5

-165.2

1.5

17

Region + Harvest + Burn + Year

1167.8

4.2

-158.7

8.0

18

Harvest + Woody + Grass + Canopy + Burn + Year

1170.1

6.4

-166.2

0.5

19

Region + Woody + Grass + Canopy + Burn + Year

1170.1

6.4

-166.6

0.1

20

Woody + Grass + Canopy + Burn + Year

1168.0

4.3

-166.4

0.3

21

Region + Harvest + Year

1169.4

5.8

-160.1

6.6

22

Woody + Grass + Canopy + Year

1167.4

3.7

-166.1

0.6

23

Burn + Year

1163.7

0.0

-158.5

8.2

24

Year

1165.6

1.9

-160.7

6.0

25

Intercept Only

1235.4

71.7

-134.2

32.5

 

Table A3. Candidate models of the survival of seedlings of Khaya senegalensis from 12 populations in two regions under different harvest regimes. Basal diameter the previous year (PrevDB) was included to account for greater survival in larger seedlings and saplings. The number of conspecific seedlings (Sdlg) was included to test for density-dependent mortality. Year was not included in the models of sapling survival, since mortality was low in some years. Population and plot within population were included as random effects. AICc was calculated from models fit with maximum likelihood to compare fixed effects.

ID

Model

Seedling

Sapling

AICc

ΔAICc

AICc

ΔAICc

1

Region*Harvest + Region*Woody + Region*Grass + Canopy + Burn + PrevDB + Sdlg + Year

1579.0

1.7

168.3

9.4

2

Region*Harvest + Region*Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1577.4

0.0

171.8

13.0

3

Region*Harvest + Region*Grass + Woody + Canopy + Burn + PrevDB + Sdlg + Year

1583.2

5.8

166.1

7.2

4

Region*Woody + Region*Grass + Harvest + Canopy + Burn + PrevDB + Sdlg + Year

1582.7

5.4

168.5

9.7

5

Region*Harvest + Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1581.6

4.2

170.3

11.5

6

Region*Harvest + Burn + PrevDB + Sdlg + Year

1590.1

12.8

167.3

8.4

7

Region*Woody + Harvest + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1581.3

3.9

172.8

13.9

8

Region*Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1582.4

5.0

171.5

12.6

9

Region*Grass + Harvest + Woody + Canopy + Burn + PrevDB + Sdlg + Year

1586.1

8.8

166.7

7.9

10

Region*Grass + Woody + Canopy + Burn + PrevDB + Sdlg + Year

1587.2

9.8

166.5

7.6

11

Region + Harvest + Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1584.7

7.3

172.4

13.6

12

Region + Harvest + Burn + PrevDB + Sdlg + Year

1592.7

15.3

168.4

9.6

13

Harvest + Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1588.0

10.6

170.3

11.5

14

Region + Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1585.8

8.5

170.8

12.0

15

Woody + Grass + Canopy + Burn + PrevDB + Sdlg + Year

1588.0

10.7

168.8

10.0

16

Region + Harvest + PrevDB + Sdlg + Year

1602.8

25.4

166.4

7.6

17

Woody + Grass + Canopy + PrevDB + Sdlg + Year

1599.8

22.4

167.6

8.7

18

Region + Burn + PrevDB + Year

1601.6

24.2

164.7

5.9

19

PrevDB + Sdlg + Year

1609.1

31.8

162.5

3.7

20

Intercept Only

1786.0

208.7

158.9

0.0


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