This three-dimensional map of the crown structure of a Redwood named Iluvatar, made by Steve Sillett, Marie Antoine and their colleagues, gives you an idea.
这张是名为“伊卢瓦塔”（Illuvatar,托尔金魔戒三部曲中的众生之父）的红杉其树冠结构的三维图， 由史蒂夫，玛丽·安东尼，以及他们的同事绘制，它能让你更好理解一些。