Appendix B. Summary of regression models that included dbh, age, and tree height as predictors of LAI for Acer saccharum, and reduced models that only included two or one of these variables as a predictor†.
Model |
R² |
Slope (SE) |
Intercept (SE) |
AIC |
∆AIC |
|||
LAI |
||||||||
y = a + age × x |
0.64 |
-0.03 (0.01) |
*** |
8.60 (0.50) |
*** |
-0.65 |
0 |
|
y = a + dbh × x |
0.51 |
-0.07 (0.02) |
** |
8.66 (0.67) |
*** |
1.92 |
2.57 |
|
y = a + height × x |
0.34 |
-0.40 (0.14) |
* |
14.53 (2.94 ) |
*** |
4.21 |
4.86 |
|
y = a + age × x + |
0.65 |
-0.03 (0.01) |
* |
8.63 (0.58) |
*** |
1.34 |
1.99 |
|
dbh × z |
-- |
-0.004 (0.03) |
-- |
-- |
-- |
|||
y = a + age × x + |
0.65 |
-0.03 (0.01) |
** |
8.24 (2.83) |
* |
1.33 |
1.98 |
|
height × z |
-- |
0.02 (0.16) |
-- |
-- |
-- |
|||
y = a + dbh × x + |
0.52 |
-0.09 (0.04) |
* |
6.16 (4.40) |
3.74 |
4.39 |
||
height × z |
-- |
0.15 (0.26) |
-- |
-- |
-- |
|||
y = a + age × x + |
0.65 |
-0.03 (0.01) |
* |
7.47 (3.94) |
3.29 |
3.94 |
||
dbh × z + |
-- |
-0.01 (0.05) |
-- |
-- |
-- |
|||
height × w |
-- |
0.07 (0.23) |
-- |
-- |
-- |
|||
† These models were only fit to A. saccharum because we could only obtain a complete core, and thus determine age accurately, for a subset of trees.
*P < 0.05, **P < 0.01, ***P < 0.0001