Lianas are a woody climbing plant that grows from the ground, beginning as small shrubs. They use other trees and plants to support them as they stretch to the upper canopy of the rain forest where there is more light. Lianas vary in size; they can be small and difficult to differentiate among the foliage, or they can grow to be as thick and substantial as the trees they grow amongst.
Lianas grow in tropical forests worldwide, predominantly in Africa, South America, Central America, Mexico and Asia. They form about 20 per cent of the woody flora in tropical forests.
Lianas have little structural support and use most of their growing energy to elongate stems and roots, stretching up towards the canopy. According to the Switzerland Center of Scientific Research, lianas thrive by attaching themselves to other plants via stem twining, "clasping tendrils arising from stem, leaf and branch modifications, thorns and spines that attach the liana to its host, downward-pointing adhesive hairs, and adhesive, adventitious roots."
Role in Ecology
Lianas have several effects on the forest ecosystem. They often dominate gaps in the forest canopy, blocking other trees and preventing the regeneration of saplings and seedlings. Scientists believe that lianas contribute significantly to the transpiration of tropical forests, especially during the dry season. Transpiration is the evaporation of water from plants. Lianas also contribute to carbon sequestration, or removing carbon dioxide from the atmosphere. The trees lianas climb suffer from constriction. This effects the movement of fluids, such as water and sap, in the tree. Sometimes this results in death for the host tree. Lianas stretch over the forest canopy, often blocking other trees from getting the light, water and nutrients they need to flourish. This unique plant also forms walkways for arboreal animals.
Liana is used by locals for medicine, house construction, food and artwork. Different species of liana have various uses. For example, rattan is used in construction and carpentry. According to the Switzerland Center of Scientific Research, one species of liana found in Cameroon, Ancistocladus korupensis, contains alkaloids that fight HIV.