Cottonwoods are so beautiful. It's a shame their method of reproduction is as complex as it is. Unlike most trees, Cottonwoods require flooding to be present in order to reproduce. The water is the only thing that triggers the tree to release its gametes. Then, it's up to chance that those gametes meet up with another. Because New Mexico lacks the necessary water needed to flood, these trees are having a difficult time staying alive in the Bosque.