1 Appendix S3. Linear selection differentials and quadratic selection gradients describing
2 selection on niche components in experimental L. fremontii families in the presence (control) and
3 absence (neighbor removal) of surrounding vegetation. Linear selection differentials were
4 calculated from simple linear regressions between each niche component (standardized to a mean
5 of zero and standard deviation of one) and family mean relative fitness, calculated across all
6 transplant locations within each competition treatment. Quadratic selection gradients were
7 estimated from multiple regressions that included both linear and quadratic terms; the quadratic
8 gradients and standard errors were doubled to estimate nonlinear selection gradients.
Linear selection differential Quadratic selection gradient a. Niche position
Control
Estimate SE t Pr >|t|
-0.28 0.20 -1.42 0.17
Neighbor Removal 0.43 0.24 1.82 0.08
Estimate
-4.39
-4.32
SE
5.31 t
-0.83
3.44 -1.26
Pr >|t|
0.42
0.22 b. Niche optimum
Control -0.09 0.20 -0.42 0.68
Neighbor Removal 0.24 0.26 1.00 0.33
1.30 5.24 0.25 0.80
-7.70 3.30 -2.23 0.03 c. Niche breadth
Control 0.71 0.14 5.05 <0.0001 -0.66 0.88 -0.75 0.46
9
Neighbor Removal 0.96 0.18 5.38 <0.0001 -1.18 1.12 -1.05 0.31