A stem held in which position is less likely to break in an ice storm?

In an ice storm, trees are particularly vulnerable to branch failures due to the added weight of the ice accumulation. The position of a stem can significantly influence its structural integrity during such stressful conditions.

When a stem is held in a horizontal position, it allows for the distribution of weight across its length. This distribution can help to minimize the bending stress that would typically lead to breakage when ice accumulates on the branches. The horizontal position reduces the leverage effect and the inverse load that would occur in other orientations, making it less likely for the stem to snap under the weight of the ice.

In contrast, when a stem is in a vertical position, it experiences more direct loading from the ice, increasing the likelihood of breakage. An inclined position shares some characteristics with the vertical position because it can create an asymmetrical load distribution that may lead to failure. Meanwhile, a rounded position is less about the angle and more about tree health and growth patterns, which do not directly correlate with the stability of a stem during ice storms.

Overall, the horizontal position provides an orientation that reduces the mechanical load on the stem in a way that enhances stability during heavy ice accumulation.