Mention jungles and images of steamy, densely overgrown forests with twisted vegetation come to mind. Jungle is a generalized term frequently used to describe tropical rain forests. Jungles consist of trees that require frost-free tropical zones and high humidity. They are found on five of Earth’s continents. Although trees in jungles tend to have similar physical appearances and structures, the species diversity numbers in the thousands, with as many as 20 to 86 different species of trees per acre.
Rain Forest Characteristics
Dense rain forests have tightly closed canopies that prevent sunlight from reaching the floor. They are regions with heavy, seasonal rainfall along with high humidity and temperatures. They consist of four distinct layers: emergent, canopy, understory and forest floor. Trees adapt for sunlight and water. Emergent trees tend to be broad-leaved evergreens and stand far above the canopy, while canopy trees have smooth leaves with deep veins or points called "drip tips" that help move water off leaf. Understory leaves are larger to capture weak sunlight. Few plants thrive in the dark, relatively dry forest floor. Most of the diverse flora and fauna exists in the upper canopies rather than the floor.
Central America Jungles
Rain forests found in Central America include the countries of Panama, Costa Rica, Honduras, Belize and southern Mexico. They share many of the same trees in their lush tropical habitats. The diversity is rich, with up to 90 species per two acres. Some familiar Central American rain forest trees include kapok, Brazil nut, cercropia, annatto, chewing gum also called chicle, abiu, mountain soursop, ilama, Astrocaryum jauari palm and the rubber tree.
South America's Amazon Rainforest
Approximately 16,000 tree species, with 227 hyperdominant species, were found in the lowland rain forest alone, according a 2013 report in the journal Science. The Amazon rain forest is considered the largest on the planet. Some common dominant trees are those of the Brazil nut family (Lecythidaceae), the nutmeg family (Myristicaceae) and palm family (Palmaceae). Many are known for commercial value including rubber tree, cacao, kapok tree, freijo, aҫaí palm and balsa.
Central Africa's Congo
Central Africa’s rain forest is second in size -- following the Amazon -- with the Congo region alone greater in area than Alaska. It consists of more than 10,000 plant species. Important commercial trees include African mahogany, gaboon and utile. Utile, an emergent tree, reaches heights of 200 feet with narrow buttresses at the ground that support the tall tree. Many emergent rain forest trees have buttresses.
South Asian jungles -- which exist today in Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Thailand and Vietnam -- possess plant diversity greater than the Amazon or central Africa. Cinnamon grows wild in Southeast Asia, India and Sri Lanka. Jelutong -- a tall, fine-textured tree -- is valued for carvings as well as for latex. Dipterocarps, at heights up to 120 feet, tower over these rain forests as emergent trees providing habitat for bees that suspend their large wedge-shaped hives under the tree’s branches. Dipterocarps are valued more for their bees than for their very hard wood.
Queensland and the Northern Territory host the rain forests of Australasia, but Australasia encompasses other small island countries – Papua New Guinea and Fiji. The aggressive strangler fig grows around host trees in this region as it stretches from the forest floor for some highly valued sunlight. A familiar houseplant, umbrella tree -- also called schefflera -- becomes a large tree but has been known to also grow as an epiphyte, piggybacking on larger trees in the canopy. Cycads and coffee remain important members of this community.