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Woody climbers are called lianas. An example would be the rattan. All climbers start life on the ground, usually having a bunch of leaves. They are low lying until there is a gap at the canopy above whereby allowing sunlight to penetrate through. With sufficient light, their growth rate is suddenly boosted and they begin an upward ascend by clinging on to the trunk of a nearby tree through hooks or by twining. During this period, the lianas do not branch out and have small widely spaced leaves. Once they have reached a height high enough for them to get a good supply of sunlight, the liana usually stop ascending up the tree and begin to branch out, producing branches that hangs down from the host tree. The leaves that grow out form the liana will now be larger and flowers may be produced. Lianas do no harm to the host tree. However some lianas can do without climbing equipment, except for horizontally spreading branches, that help support the liana and prevent the stems from sagging down. These branches are in fact common features in many lianas. Lianas in the rainforest play a very important role. They help to further close the canopy, which help to stabilize the microclimate further. Lianas often tie tree crowns together so that in a light storm, everything remains upright. However, during a heavy storm, everything may just come down to the ground. Studies have also shown that lianas contribute 36% of all rainforest litter. This is a large amount considering that lianas only have a wood mass of 5% of that of trees. Many animal species also depend on lianas for protection. The two-toed sloth is an example. They are found to prefer trees that have a large mass of lianas. Since two toed sloths are inactive during daylight hours, they need to be protected from predators. Therefore by sleeping within a mass of lianas, any potential predators would have to make way through the lianas and cause motion that will wake the sloth. This way there will be time for the sloth to either attack the predator or flee the tree. Lianas also serve as pathways for the two-toed sloth. As said earlier an example of a liana is the rattan. Rattans are distributed along the primary forests of West Africa to the islands of Farmosa and Fiji. The stems of this wooden grass are either solitary or in clumps. The stems have a constant width around 1-8 cm in thickness. Each long rattan stems often have about 10 to 15 leaves. Each leaf ends is accompanied by a long, strong whip with sharp, backwards-pointing that helps to anchor the plant on to the host vegetation.
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