Ive got my copy of "Workbenches" by Chris Schwarz open in front of me, theres a section in there that lists the stiffness of some timbers common in North America. What surprised me is that rock maple is actually LESS stiff than both southern yellow pine and douglas fir, heres the E values:
Hard maple: 1.83
SYP: 1.93 (+ 5%)
Douglass fir: 1.95 (+ 7%)
Yellow birch: 2.01 (+ 10%)
Hickory: 2.16 (+ 18%)
vs the densities:
Hard maple: 0.63
SYP: 0.67 (+ 6%)
Douglass fir: 0.48 (- 24%)
Yellow birch: 0.62 (- 2%)
Hickory: 0.72 (+ 14%)
Dont know where wenge, purpleheart and friends compare on this scale.
I think woodpecker did some research into European timbers, I'll see if I can find them.
Looking at other sources, some of those figures look like "best case" numbers. For example, for
doug fir, the FPL of the USDA shows the MOE to be 1.49-1.95 Mpsi, depending what part of the country the samples were taken from.
For SYP, according to the
Southern Pine Council, it can be any of more than four different species, and
dimensional lumber will have an MOE of 1.4-1.9 Mpsi depending on the size and grade selected. By the FPL, the four main species show a range of 1.75-1.98 Mpsi.
The FPL agrees with the 2.01 figure for yellow birch, but
Link Removed are from 1.15-2.17. So if you have control over what species you're buying, fine; but if you're just buying "birch," maybe not so good!
And this is all without counting the individual tree factor. Every maple does not show an MOE of 1.83 Mpsi.
So, rather than the way you put it, I'd be more likely to say, "southern yellow pine and douglas fir
can be stiffer than hard maple."