Gunung Leuser National Park, Indonesia Photograph by Herman Rijksen   Runs parallel to the west coast of the Indonesian island of Sumatra Tropical and Subtropical Moist Broadleaf Forests   28,100 square miles (72,900 square kilometers) -- about half the size of Michigan Relatively Stable/Intact

· Mountain Mammals
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern

Mountain Mammals

Visit the Sumatra Montane Rain Forests and you'll have a chance to see some of the largest--and most endangered--creatures in all of Asia. Sumatran rhinos, Malayan tapirs, and Asian elephants browse in the understory, tigers stalk unsuspecting prey, and orangutans clamber up the trees in search of food and shelter. This ecoregion also supports incredible plant and bird life, making it one of the most outstanding examples of montane rain forests in Asia.

Special Features

The forests of this ecoregion lie above 3,300 feet (1,000 meters) along the Barisan mountain range of Sumatra. This mountain range formed about 70 million years ago. Today its forests receive more than 100 inches (250 centimeters) of rainfall each year. Temperature and cloud level have combined to create three distinct forest zones on the mountains. The lower montane forests consists of dipterocarps, oaks, laurels, and other tree species. Conifers dominate the upper montane forests. And small, stunted conifers grow in the subalpine forest, near grasses, rushes, sedges, and colorful herbaceous plants.

	The Rafflesia arnoldii plant produces the largest flower in the world. The monster flower can grow up to 1 yard (1 m) wide and weigh up to 24 pounds (11 kg). It smells like rotting meat, which helps to attract a plethora of flies and other pollinating insects.

Wild Side

Much of Sumatra's wildlife can be divided into two different groups. One group of species--including white-handed gibbons and 17 bird species--is found only north of Lake Toba, which formed 75,000 years ago during a volcanic eruption. The other group of species--including dark-handed gibbons, banded leaf monkeys, Sumatran rabbits, and 10 bird species--is found only south of this lake. Sumatra's montane forests are home to several endemic species, including Thomas' leaf monkeys, Sumatran rabbits, Hoogerwerf's rats, Sumatran shrew-mice, and two birds--the Sumatran cochoa and the Sumatran ground-cuckoo. These forests are also home to the world's largest flower.

Cause for Concern

Despite Sumatra's dense human population, this ecoregion contains several large blocks of intact forest. Unfortunately, widespread logging is so depleting the lowland forests of the region that these upper elevations are likely to become more fragile and also more attractive to logging operations. Illegal logging, rampant throughout all of Indonesia, threatens the habitat of many species, including prime habitat for the orangutans, siamangs, and white-handed gibbons.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.