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 25:1319–1329. 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 |