Table 7 Influence of spatial location and type of competition on branch-free bole length in potential future crop trees in group plantings. Interaction terms were built between the type of competition and the location of target oak trees (inner section or periphery of groups) in two separate models for intra- and interspecific competitions, respectively. Number of target trees included for this analysis was 79. Here, β refers to model estimate in GLM. For a significant effect, upper or lower limit of the confidence interval for the standard error of β should not reach 0
Independent variables | Model estimates (β) | Standard error of β | 95 % Wald confidence interval | Wald χ2 value | d.f. | p value | |
|---|---|---|---|---|---|---|---|
Lower | Upper | ||||||
Intercept | 4.0316 | 0.2862 | 3.4707 | 4.5925 | 198.4439 | 1 | 0.0000 |
Inner section × intraspecific competition | 0.1277 | 0.0808 | −0.0307 | 0.2860 | 2.4979 | 1 | 0.1140 |
Periphery × intraspecific competition | 0.0043 | 0.0959 | −0.1836 | 0.1921 | 0.0020 | 1 | 0.9645 |
Maximum likelihood estimate | 1.3460 | 0.2156 | 0.9835 | 1.8424 | |||
Intercept | 4.5899 | 0.1905 | 4.2166 | 4.9632 | 580.7293 | 1 | 0.0000 |
Inner section × interspecific competition | −0.0388 | 0.0837 | −0.2028 | 0.1251 | 0.2153 | 1 | 0.6426 |
Periphery × interspecific competition | −0.3163 | 0.1011 | −0.5144 | −0.1182 | 9.7906 | 1 | 0.0018 |
Maximum likelihood estimate | 1.2500 | 0.2002 | 0.9135 | 1.7113 | |||