SHOP PRODUCTS
Houzz Logo Print
parker25mv

Why tree ferns are only found in the Southern hemisphere

parker25mv
8 years ago
last modified: 8 years ago

Some of you may be wondering why there are no species of tree ferns native to the Northern hemisphere. The answer is that tree ferns, with a big part of their woody vascular structure permanently above ground, have difficulty dealing with freezing temperatures.

The surface area of the Southern hemisphere is covered by more ocean than the Northern hemisphere; most of the landmass is under a coastal influence that helps moderate temperatures, preventing it from going below freezing.

Tree ferns would thrive in the Pacific Northwest except for the fact there are about 2 weeks in Winter where the temperatures dip slightly below freezing.

We can look at the forest structure in Southeastern Australia. The climate is fairly dry but moderate. Tree ferns thrive under the canopy of tall eucalyptus trees. Why do tree ferns grow so well here? Well, unlike other forests, eucalyptus forests let more light down to the forest floor (a big tree fern needs more light than a smaller fern). There is not as much water in this forest biome to enable the eucalyptus to form a dense canopy shading out all the light. But there is still some partial shade down there, and because of the coastal influence the humidity in the air never drops too low. These are suitable conditions for tree ferns. (So in other words, not a lot of rain but the air is not too dry) The tree ferns also do not need as much water because they are partially shaded by the eucalyptus from the scorching sun.

Comments (5)

Sponsored