Frequently asked questions

17 - Q : Does tension stress vs. compression stress make a difference in structural failure of tree branches?

I'd say the answer is "no". Whether you support a cantilevered beam from overhead or brace it from below, failure of the structure is based on the intrinsic strength of the brace, not in the direction of the force acting upon it.

Conifers suffered less damage in the recent ice storm because of their excurrent architectural design ... that is, many small, equally spaced branches in whorls distributed on a strong central axis. This design evolved, to a great extent, in response to environmental stress factors of wind and snow loading in northern climates.

The decurrent form of most broadleaf species ... relatively large, unequally spaced branches without a strong central axis, is less adapted to these sorts of forces. It probably evolved in reaction to intense competition for space, and is relatively more efficient for this purpose.

One thing to note is that the tree species that suffered the greatest damage are also among the fastest to resprout and fill in the forest gaps that have been created.

Canadian Forest Service
Natural Resources Canada