Stepwise Model Path 
Analysis of Deviance Table
Initial Model:
Fraxspp ~ pradyy + ddeg556 + bio4 + prcp49 + slp + topos + dem_aspv +
dem_flacc10rd + prcp103 + I(pradyy^2) + I(ddeg556^2) + I(bio4^2) +
I(prcp49^2) + I(slp^2) + I(topos^2) + I(dem_aspv^2) + I(dem_flacc10rd^2) +
I(prcp103^2)
Final Model:
Fraxspp ~ ddeg556 + bio4 + prcp49 + I(ddeg556^2) + I(bio4^2) +
I(prcp49^2)