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Types of Grass in a Tropical Dry Forest

A tropical dry forest, also called a tropical deciduous forest, is a forest biome that receives rain for only a brief portion of the year. Because of the dry climate, trees do not maintain their foliage year round, but lose their leaves during the drier seasons to conserve moisture. Much of the land formerly covered by tropical dry forests has now been converted by humans into pastureland and farmland.

Grasses
- Most grasses do not grow well in dry tropical forests. Though many grasses are adapted to drier climates, they must have access to sunlight to grow. Unfortunately for them, the growing season is dependent upon seasonal rains, and during that part of the year sunlight is blocked by the much larger trees of the forest. Typically, grasses only grow on the edges of forests, where there is adequate sunlight during the rainy months of the year. Some of the Hawaiian Islands have no native grasses at all.
Bamboo
- One of the important exceptions is bamboo, the largest species of grass. Bamboo can grow up to 100 feet tall, and compete with the trees for sunlight. Because it grows so tall, many people have trouble identifying it as a grass, but it is in fact a member of the family Poaceae, or true grasses. Bamboo is most significant economically and ecologically in Asia, but it also grows in Africa, Australia, and Latin America.
Other Grasses
- Another exception is Lasiacis ruscifolia, another tall grass that can grow up to 25 feet high. Lasiacis ruscifolia is a perennial grass found in Mexico and South America. Though common in some areas, it does not have the economic significance of bamboo. Other native grasses in Latin America include sourgrass (Digitaria insularis) and Judd's grass (Leptochloa virgata), both of which are found in the southern United States down to northern South America.
Invasive Species
- Some grasses have an ecological impact far from their native territory. In places where clear cutting has occurred for lumber or to make room for pastureland, non-native species of grass have managed to gain a foothold and drive out native species of plant life. In Hawaii, the African fountain grass (Pennisetum setaceum) and other invasive species have added to the difficulties of the native plants. These grasses can be highly flammable during the dry season, and when they catch fire the flames may spread to nearby sections of forest. The damaged area of the forest enables the African fountain grass to spread further. A similar problem is occurring in Bolivia, where clear-cutting has allowed the introduction of Urochloa (Panicum) maxima, an invasive pasture grass from Africa.

Nature