A liana is a long- stemmed, woody

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themselv ...

that is

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...

ed in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the

canopy Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an a ...

in search of direct sunlight. The word ''liana'' does not refer to a

taxonomic Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...

grouping, but rather a habit of plant growth – much like ''

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

'' or ''

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

''. It comes from standard French ''liane'', itself from an Antilles French dialect word meaning to

sheave A sheave () or pulley wheel is a grooved wheel often used for holding a belt, wire rope, or rope and incorporated into a pulley. The sheave spins on an axle or bearing inside the frame of the pulley. This allows the wire or rope to move fre ...

Ecology

Lianas are characteristic of

tropical moist broadleaf forests Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature. Description TSMF is generally found in large, discont ...

(especially seasonal forests), but may be found in

temperate rainforests Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American Paci ...

and temperate deciduous forests. There are also

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

lianas, for example the members of the ''

Clematis ''Clematis'' is a genus of about 300 species within the buttercup family, Ranunculaceae. Their garden hybrids have been popular among gardeners, beginning with ''Clematis'' × ''jackmanii'', a garden standby since 1862; more hybrid cultivars ...

'' or ''

Vitis ''Vitis'' (grapevine) is a genus of 79 accepted species of vining plants in the flowering plant family Vitaceae. The genus is made up of species predominantly from the Northern Hemisphere. It is economically important as the source of grapes, b ...

'' (wild grape) genera. Lianas can form bridges amidst the forest canopy, providing

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

animals with paths across the forest. These bridges can protect weaker trees from strong winds. Lianas compete with forest trees for sunlight, water and nutrients from the soil. Forests without lianas grow 150% more fruit; trees with lianas have twice the probability of dying. Lianas may be found in many different plant

families Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

. One way of distinguishing lianas from trees and shrubs is based on the stiffness, specifically, the Young's modulus of various parts of the stem. Trees and shrubs have young twigs and smaller branches which are quite flexible and older growth such as Trunk (botany), trunks and large branches which are stiffer. A liana often has stiff young growths and older, more flexible growth at the base of the stem.

Habitat

Lianas compete intensely with trees, greatly reducing tree growth and tree reproduction, greatly increasing tree mortality, preventing tree seedlings from establishing, altering the course of regeneration in forests, and ultimately affecting tree population growth rates. Lianas also provide access routes in the forest

for many

animals, including ants and many other invertebrates, lizards, rodents, sloths, monkeys, and lemurs. For example, in the Eastern tropical forests of Madagascar, many lemurs achieve higher mobility from the web of lianas draped amongst the vertical tree species. Many lemurs prefer trees with lianas for their roost sites. Lianas also provide support for trees when strong winds blow. However, they may be destructive in that when one tree falls, the connections made by the lianas may cause many other trees to fall. As noted by Charles Darwin, because lianas are supported by other plants, they may conserve resources that other plants must allocate to the development of structure and use them instead for growth and reproduction. In general, lianas are detrimental to the trees that support them. Growth rates are lower for trees with lianas; they directly damage hosts by mechanical abrasion and strangulation, render hosts more susceptible to ice and wind damage, and increase the probability that the host tree falls. Lianas also make the canopy of trees more accessible to animals which eat leaves. Because of these negative effects, trees which remain free of lianas are at an advantage; some species have evolved characteristics which help them avoid or shed lianas.

Examples

Some families and genera containing liana species include:

References

External links

Lianas and Climbing Plants of the Neotropics

Lianas and Climbing Plants of the Neotropics: Family Treatments
* 'Vines and Lianas' by Rhett Butler, at http://rainforests.mongabay.com/0406.htm * {{botany Vines, * Plant morphology Biology terminology Plant life-forms Plants by habit