Appendix E. Results of the stepwise backward regression.
TABLE E1. Deer browse level on Trillium (% Trillium browsed) is the strongest predictor of the demographic metrics of unpalatable, unbrowsed Arisaema triphyllum across seven PA natural sites where the two species co-occur. Stepwise backward regression model was performed using % Trillium browsed, density of flowering Trillium, total Arisaema population density, and soil quality scores (PC1 from PCA – see Methods in main article) as predictors. Variables not listed in the table were not significant for that analysis.
Dependent Variable |
Predictors |
Model significance |
Model R2 |
Coefficient (β) |
t stat |
P value |
Reproductive plant size |
|
0.001 |
0.98 |
|
|
|
|
% Trillium browsed |
|
|
-0.12 |
-12.8 |
0.001 |
|
Soil quality score (PC1) |
|
|
0.12 |
2.4 |
0.16 |
|
Flowering Trillium density |
|
|
0.75 |
6.2 |
0.009 |
Population sex ratio |
|
0.005 |
0.85 |
|
|
|
|
% Trillium browsed |
|
|
1.55 |
5.6 |
0.005 |
|
Soil quality score (PC1) |
|
|
-1.1 |
-0.47 |
0.67 |
|
Flowering Trillium density |
|
|
3 |
0.73 |
0.51 |
Seed rain m-2 |
|
0.009 |
0.81 |
|
|
|
|
% Trillium browsed |
|
|
-0.01 |
-4.7 |
0.009 |
|
Soil quality score (PC1) |
|
|
-0.02 |
-1.4 |
0.24 |
|
Flowering Trillium density |
|
|
-0.01 |
-0.46 |
0.68 |