Borneo's lowland rainforests host more plant species than the entire continent of Africa.

Countries & Cities · Published 30 September 2026 Swipe more like this →

In short: Spanning over 400,000 square kilometers, the lowland rainforests of Borneo represent the world's most diverse botanical hub. From the massive, white-trunked Koompassia excelsa to the parasitic Rafflesia, this ecosystem thrives in a stable, wet climate. Yet, this ancient biological treasure is rapidly vanishing due to industrial conversion and logging.

The Borneo lowland rain forests cover approximately 428,438 square kilometers, accounting for about 57% of the island's total land area. These forests exist primarily below 1,000 meters in elevation and are shared between Indonesia, Malaysia, and Brunei. The region is defined by a stable, tropical climate where temperatures rarely fluctuate by more than 10°C and monthly rainfall consistently exceeds 200 millimeters. This environment supports an extraordinary level of biodiversity, including an estimated 10,000 plant species—a figure that exceeds the total plant variety found across the entire African continent.

The forest structure is dominated by mixed dipterocarp communities, which form a closed canopy between 24 and 36 meters high. Emergent trees, such as the Koompassia excelsa, can reach heights of 85 meters, towering above the canopy layer. Dipterocarps are the primary constituents of this emergent stratum, representing up to 80% of the tallest trees. Below this, the understorey is characterized by shade-tolerant species and the phenomenon of cauliflory, where flowers and fruits grow directly from tree trunks. The forest floor hosts unique biological wonders, including the Rafflesia arnoldii, which produces the world's largest flower, measuring over a meter in width.

The region's history is tied to the Pleistocene glacial epoch, when Borneo was part of a larger landmass known as Sundaland. This connection allowed for the migration of species that now inhabit the island, ranging from the least pygmy squirrel to the Asian elephant. Despite this rich heritage, the ecosystem faces severe threats. Over the past 50 years, Borneo has lost more than half of its rainforest cover. While conservation efforts have established protected areas covering 6.267% of the ecoregion, ongoing deforestation for oil palm and timber plantations continues to jeopardize the habitat of critically endangered species like the Sumatran rhinoceros and the Bornean orangutan.

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