Table 1 Effect of tree species, canopy cover, soil depth, and their interactions on seedling density and species diversity, with statistical results of GLM (F, P, R 2adjusted values)
|  | Means ± 95% C.I. | ||
|---|---|---|---|
Seed density (n/m2) | Species richness (n/m2) | Shannon Wiener species diversity (H’) | |
Acacia robusta | |||
 Inside canopy | |||
 0–5 cm | 31.5 ± 5.30 | 12.5 ± 0.90 | 1.89 ± 0.10 |
 5–10 cm | 12.27 ± 2.3 | 7.5 ± 1.50 | 1.49 ± 0.20 |
 Outside canopy | |||
 0–5 cm | 8.84 ± 2.20 | 12.5 ± 0.9 | 1.64 ± 0.14 |
 5–10 cm | 12.39 ± 2.90 | 5.75 ± 1.3 | 1.29 ± 0.16 |
Balanites aegyptiaca | |||
 Inside canopy | |||
 0–5 cm | 9.63 ± 1.80 | 13.0 ± 2.04 | 1.87 ± 0.16 |
 5–10 cm | 17.82 ± 4.12 | 5.5 ± 1.04 | 1.26 ± 0.10 |
 Outside canopy | |||
 0–5 cm | 24.60 ± 4.31 | 12.0 ± 1.41 | 1.91 ± 0.10 |
 5–10 cm | 12.63 ± 3.14 | 6.0 ± 1.10 | 1.19 ± 0.10 |
Ziziphus spina-Christi | |||
 Inside canopy | |||
 0–5 cm | 18.48 ± 4.23 | 16.0 ± 1.50 | 2.17 ± 0.18 |
 5–10 cm | 8.34 ± 1.40 | 15.3 ± 0.80 | 1.77 ± 0.08 |
 Outside canopy | |||
 0–5 cm | 6.75 ± 1.30 | 9.0 ± 0.91 | 1.69 ± 0.20 |
 5–10 cm | 7.03 ± 1.40 | 7.3 ± 0.48 | 1.53 ± 0.17 |
 Tree species (TS) | |||
  F (df = 2, 36) | 3.920 | 5.820 | 3.430 |
  P | 0.021 | 0.007 | 0.043 |
 Canopy cover (CC) | |||
  F (df = 1, 36) | 4.070 | 16.510 | 6.320 |
  P | 0.044 | 0.001 | 0.017 |
 Soil depth (SD) | |||
  F (df = 1, 36) | 5.270 | 38.240 | 15.130 |
  P | 0.022 | <0.001 | 0.001 |
 TS × CC | |||
  F (df = 2, 36) | 4.670 | 10.750 | 1.580 |
  P | 0.010 | 0.001 | 0.221 |
 TS × SD | |||
  F (df = 2, 36) | 0.600 | 7.630 | 8.470 |
  P | 0.549 | 0.002 | 0.001 |
 CC × SD | |||
  F (df = 1, 36) | 1.040 | 0.420 | 1.740 |
  P | 0.308 | 0.521 | 0.196 |
 TS × CC × SD | |||
  F (df = 2, 36) | 8.280 | 0.750 | 1.330 |
  P | 0.003 | 0.478 | 0.280 |
 Adjusted R 2 | 0.650 | 0.730 | 0.570 |