Most of Southeast Asia are in the tropics, so there are similarities in climate as well as plant and animal life throughout the region. Temperatures are generally warm. The area offers many unique sea and jungle products, which were highly desired by international traders in early times. For example, small islands in eastern Indonesia were once the world’s only source of cloves, nutmeg, and mace. The entire region is affected by the monsoon winds, which bring fairly predictable rainy seasons. The monsoons enabled Southeast Asia to play a role in trade between India and China.
There are some differences in the physical environment of the mainland and islands of Southeast Asia. The mainland has long rivers that begin in the highlands separating Southeast Asia from China and India. Extensive lowland plains are suited to rice-growing ethnic groups, such as the Thais, the Burmese, and the Vietnamese, who developed settled cultures. The highlands were occupied by tribal groups, who developed their identity through distinctive styles in clothing, jewelry, and hairstyles. Mainland Southeast Asia has a long coastline. The communities in these regions were also part of the trading network.
The islands of maritime Southeast Asia range from the very large (for instance, Borneo, Sumatra, Java, Luzon) to tiny pinpoints on the map (Indonesia contains about 17,000 islands). The islands have jungles, which made land travel there difficult. Southeast Asians found it easier to sail between different areas. The oceans that connected coasts and neighboring islands formed zones where people shared similar languages and were exposed to the same religious and cultural influences. The modern countries created by colonial powers do not reflect logical cultural divisions.
The Southeast Asia seas are shallow, making them warm and not too salty. This is an ideal environment for fish, coral, seaweeds, and other products. The region as a whole generally has few severe storms. However, there are many active volcanoes and earthquakes.
Source: Introduction to Southeast Asia: Geography, Environment, and Cultural Zones
©2020 Asia Society