Table 2.
Parameter estimates, standard errors and P-values for the regression model for inequality of size and size increment
| Candle Lake–Rich |
Candle Lake–Poor |
Thompson–Rich |
Thompson–Poor |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | s.e. | P | Mean | s.e. | P | Mean | s.e. | P | Mean | s.e. | P | |
| Volume | ||||||||||||
| Intercept | 2·3 × 10−1 | 4·6 × 10−2 | <0·01 | 1·6 × 10−1 | 1·1 × 10−2 | <0·01 | 2·1 × 10−1 | 2·8 × 10−2 | <0·01 | 5·5 × 10−1 | 8·8 × 10−3 | <0·01 |
| DENS | 1·5 × 10−4 | 1·8 × 10−5 | <0·01 | 1·1 × 10−4 | 4·0 × 10−6 | <0·01 | 9·7 × 10−5 | 1·6 × 10−5 | <0·01 | −2·1 × 10−5 | 2·3 × 10−6 | <0·01 |
| SIZE | 3·9 × 10−1 | 1·2 × 10−1 | <0·01 | 1·1 × 10 0 | 9·9 × 10−2 | <0·01 | 1·6 × 10−1 | 1·4 × 10−1 | 0·26 | −1·2 × 10 0 | 2·6 × 10−1 | <0·01 |
| COMP | −3·2 × 10−3 | 3·7 × 10−4 | <0·01 | −1·0 × 10−3 | 1·0 × 10−4 | <0·01 | −8·1 × 10−4 | 1·3 × 10−4 | <0·01 | −1·4 × 10−3 | 1·0 × 10−4 | <0·01 |
| AVI | 7·2 × 10−4 | 1·4 × 10−3 | 0·61 | 3·8 × 10−4 | 9·9 × 10−4 | 0·70 | 9·5 × 10−4 | 1·1 × 10−3 | 0·41 | −2·4 × 10–3 | 2·7 × 10–3 | 0·37 |
| AVI1 | 4·4 × 10−3 | 1·4 × 10−3 | <0·01 | −1·0 × 10−3 | 9·9 × 10−4 | 0·32 | −1·3 × 10−3 | 1·0 × 10−3 | 0·22 | −3·9 × 10–3 | 2·8 × 10–3 | 0·17 |
| Adjusted R2 | 0·97 | <0·01 | 0·99 | <0·01 | 0·98 | <0·01 | 0·85 | <0·01 | ||||
| Volume increment | ||||||||||||
| Intercept | 3·1 × 10−1 | 2·5 × 10−1 | 0·23 | 4·1 × 10−1 | 8·9 × 10−2 | <0·01 | 6·4 × 10−1 | 2·0 × 10−1 | <0·01 | 8·2 × 10−2 | 5·7 × 10−2 | <0·01 |
| DENS | 1·3 × 10−4 | 9·7 × 10−5 | 0·18 | −2·5 × 10−5 | 3·1 × 10−5 | 0·42 | −1·4 × 10−5 | 1·1 × 10−4 | 0·89 | −1·2 × 10−4 | 1·5 × 10−5 | <0·01 |
| SIZE | 1·0 × 10 0 | 6·6 × 10−1 | 0·12 | −1·2 × 10 0 | 7·7 × 10−1 | 0·12 | −4·7 × 10−1 | 9·9 × 10−1 | 0·63 | −1·1 × 10 1 | 1·7 × 10 0 | <0·01 |
| COMP | −1·9 × 10−3 | 1·9 × 10−3 | 0·32 | 3·7 × 10−3 | 8·2 × 10−4 | <0·01 | −1·0 × 10−3 | 9·6 × 10−4 | 0·28 | 6·1 × 10−3 | 6·5 × 10−4 | <0·01 |
| AVI | −2·8 × 10−3 | 7·6 × 10−3 | 0·71 | −1·4 × 10−2 | 7·8 × 10−3 | 0·07 | −2·0 × 10−2 | 8·2 × 10−3 | 0·02 | −4·9 × 10−2 | 1·7 × 10−2 | <0·01 |
| AVI1 | −2·4 × 10−2 | 7·5 × 10−3 | <0·01 | −2·0 × 10−2 | 7·8 × 10−3 | 0·01 | −8·8 × 10−3 | 7·2 × 10−3 | 0·23 | −1·9 × 10−2 | 1·8 × 10−2 | 0·29 |
| Adjusted R2 | 0·41 | <0·01 | 0·54 | <0·01 | 0·42 | <0·01 | 0·85 | <0·01 | ||||
The variables in the table are stand density (DENS), mean tree volume (SIZE), average amount of competition to which each tree is subject (COMP), where competition is calculated using a distance-weighted absolute size index, and stand-level annual volume increment in the current year (AVI) and 1 year previously (AVI1).
Parameters in bold type were significant at P <0·05.