Redwoods are tall. Known scientifically as Sequoia sempervirens, this species is home to the tallest tree known to science. Even the branches of most redwoods would put all but the tallest trees to shame. It is no wonder then that the branches and crotches of these trees can sustain a lot of canopy debris. As debris builds up, it soon begins supporting entire floral communities of ferns, forbs, shrubs, and even other trees.
These epiphytic communities are hot spots of diversity among the redwood canopy. The sheer mass of these mats, with some weighing hundreds of kilograms, means they can hold a lot of water. Organisms that otherwise could not exist in such exposed areas find a safe haven free of desiccation. Everything from microbes to aquatic copepods call these places home. It is no wonder then that predators also haunt these microcosms.
It has been discovered that at least one species of salamander, the wandering salamander (Aneides vagrans) lives at least some of its life in redwood canopies. Though it is not solely a denizen of these trees, they have been found living among these mats during both the dry and wet seasons leading some researchers to believe that at least some individuals live out their entire lives up in the canopy. The mats hold so much water that the microclimates around them stay favorable for these amphibians year round. As roots decay within the mat, small interconnected tunnels form, offering even more protection in an otherwise chaotic environment.
Photo Credit: John Clare (http://bit.ly/1HnKtyp)
Further Reading:
http://www.fs.fed.us/…/publications/welsh/captured/psw_2006…