Trimming Branches

One morning I was trimming back the branches that were gradually filling in the open space of a favorite trail. Then I sat to rest beside a streambed. Thanks to my morning’s work, I suddenly saw the explanation for something I’ve always admired: the way dead streamside trees tend to fall across the stream, creating dams and slowing erosion.  Since trees do not grow in the stream, the space above the stream is open and full of sunlight. For trees growing near the stream, the branches that face the stream receive more light than the branches growing the other direction. Therefore those branches grow more, out into the open space. Over the years, this disproportionate growth “bends” trees out over the stream. The tree’s center of weight is cantilevered out over the stream. Therefore when the tree dies, it naturally falls towards the stream.