A new field guide untangles identification of tropical vines
STRI/DICYT A striking feature of tropical forests, woody vines or lianas compete with trees for light, slowing tree growth or even killing them. Lianas are taking over forests across the Americas, but little is known about their biology. A new field guide to these important plants, Lianas y Enredaderas de la Isla de Barro Colorado, Panamá,, published by the Smithsonian Tropical Research Institute (STRI), is an invaluable resource for anyone wanting to learn more about them.
The Spanish-language guide (Lianas and Vines of Barro Colorado Island, Panama in English), is by STRI’s Rolando Pérez, Salomón Aguilar, Nefertaris Daguerre, and Andrés Hernández, and long-time STRI Research Associate Stefan Schnitzer of Marquette University.
Lianas can be difficult to identify. Out of reach in the forest canopy, their leaves and flowers are sometimes not even visible from the ground. But their stems, accessible at ground level, vary greatly in appearance, twining around trunks or climbing using tendrils, hooks, spines, adhesive pads, or roots that sprout from their shoots.
The new guide is designed to make liana identification easy even for amateurs. It includes 124 species of the most common lianas and vines in the Barro Colorado plot. Each species account includes a basic description of the plant, with details of how to recognize it and distinguish it from similar species, as well as a summary of its distribution in Panama and elsewhere.
Common names in Spanish, and traditional uses for medicine, handicrafts, and construction are also included. A map shows where the species has been recorded in the 50-hectare plot. The facing page shows color photos of leaves, flowers, fruits, stems, and other characteristics, with the features most important for identification highlighted. A pictorial glossary to botanical terms follows.
Barro Colorado Island, a Smithsonian research site, is the best-studied tropical forest in the world. In 1980, a 50-hectare tree census plot was established on the island, in which all trees and shrubs more than one centimeter in diameter at breast height were tagged, mapped, and measured. So far seven censuses have been conducted, and more 220,000 plants of 298 species are currently marked. In 2007 this census was extended to the lianas in the plot, recording more than 67,000 individuals of 163 species in 37 families. Since many species are widespread in New World tropical forests, the guide will be useful far beyond Barro Colorado Island and Panama.
Lianas represent up to a third of all stems in some tropical forests. These plants and other climbers piggyback on trees to scramble into the sunlit upper layers of the canopy without having to manufacture sturdy trunks of their own. This energy-saving strategy allows them to grow faster than free-standing trees and often out-compete them, spreading their leaves over the canopy and blocking light that would otherwise reach their hosts.
Global climate change seems to be favoring the growth of lianas over trees in some tropical forests, with possible far-reaching effects on forest ecology and the ability of these forests to accumulate and store carbon. The new guide will be an essential tool for continuing studies of the role lianas and vines play in the ecology and dynamics of tropical forests.