I'd go to the wood handbook for something like that to get a sense of the relative strengths, these are not the allowable design values they are the properties of the clear wood itself, independent of grade and safety factors. I don't know which poplar you have, look it up in a tree guide.

Paper birch ;

Specific gravity .55

Modulus of rupture 12,300 psi

Modulus of elasticity 1.59

shear 600 psi

White ash

SG .60

MOR 15,000

E 1.74

Fv 1,910

White pine

SG .35

MOR 8,600

E 1.24

Fv 900

Eastern Hemlock

SG .40

MOR 8,900

E 1.2

Fv 1060

Red Maple

SG .54

MOR 13.400

E 1.64

Fv 1850

Sugar maple

SG .63

MOR 15,800

E 1.83

Fv 2330

The only wood that holds a candle to the ash is the maples, which is what baseball bat manufacturers figured too. I'd try to find some maple or more ash locally and borate the wood to frustrate the bugs.