Lianes

Not all plants which thrust their way into the forest canopy are trees. Lianes, for example, have their roots in the forest floor, but rely for their support upon existing trees. Often starting out as shrubs, the lianes put out long branches which attach themselves to tree trunks and climb up until they reach the sunlight, at which point they generate leaves and frequently create large crowns.

Epiphytes

Like the lianes, epiphytes do not provide their own support, but in contrast they are not rooted in the ground at all. Instead, they grow on the surface of the canopy trees, rooting in crevices where humus has accumulated. These roots, however provide only an anchorage, and the epiphytes do not draw their nutrients from the host tree. Exactly where these plants do obtain their nutrients varies from one species to another, some collecting falling plant matter, others receiving organic matter from the insects which pollinate them. Common epiphytes are orchids, bromeliads and ferns.

Found only in the tropical rain forests, stranglers start out as epiphytes, but at a certain point in their growth they produce roots which wrap around the trunk of the tree on which they live, and descend into the ground. This provides them with increased nutrients, allowing them to grow towards the canopy. Eventually the strangler surrounds its supporting tree with roots, which ultimately kills it. However, the trunk of the tree remains, and continues to support the strangler. Most stranglers are figs.

Exploration | Tropical rain forests | Epiphytes, Lianes and Stranglers | On the Line home page