Plants in the Wet Tropics - General Information

The word 'rainforest' is an umbrella term for a great variety of forest types with different structures and collections of species. The forest type is dictated by environmental parameters such as altitude, soil composition, amount of rainfall and drainage.

The Wet Tropics provides an unparalleled living record of the ecological and evolutionary processes that shaped the flora and fauna of Australia over the past 415 million years. Australia has been isolated from other land masses for millions of years and this has helped shape our distinct floral and faunal assemblages.

Humid tropical regions throughout the world are relatively new and although they are rich in numbers of species, the level of endemism is surprisingly low. (Endemic species are those which are restricted to a certain area and occur nowhere else.)

• About 3,000 plant species from 210 families are found here, representing about 17% of Australia's vascular plants.
• More than 700 species of these, or 23% of the total, are found only in the World Heritage Area.
• More than 395 rare or threatened plants species are protected within the World Heritage Area and 330 of them are found only in this area. More than 62 of them are considered endangered or vulnerable.
• Of the 49 monotypic genera (a genus that has only one species) found in the area, 19 are listed as rare or vulnerable.
• Thirteen out of the world's 19 families of primitive flowering plants are here and within these families, there are least 50 species found only in the Wet Tropics.

WARNING: DO NOT EAT ANY RAINFOREST PLANTS OR FUNGI! TOXIC PLANTS WILL MAKE YOU VERY SICK OR COULD EVEN KILL YOU.

Rainforest in the Wet Tropics crosses three major landscape types:

• the uplands and tablelands of the Great Dividing Range
• the intermediate eastern escarpment
• the lowland coastal plain

The tablelands consist of undulating country at around 800 metres in altitude, with numerous summits rising to more than 1,200 metres (3,936 feet). The highest peak is Mt Bartle Frere which reaches 1,622 metres (5,320 feet).

To the east of the tablelands lies the rugged topography and great environmental diversity of the eastern escarpment.

The coastal lowlands consists of an alluvial plain interrupted by ridges of the Great Divide and several small coastal mountain chains, as well as several large rivers such as the Herbert, North and South Johnstone, Tully, Russell-Mulgrave, Barron, Daintree and Bloomfield.

Many of the distinctive features of the region are related to the high rainfall and terrain diversity. The mean annual rainfall ranges from about 1200mm (4 feet) to over 8000 mm (26 feet). The rainfall is distinctly seasonal with over 60% falling in the summer months of December to March. Compared with other tropical rainforests of the world, the wetter parts of the region lie at the extremely wet end of the hydrological spectrum.

Intense tropical cyclones (hurricanes) are a feature of the region's climate and one of the factors shaping the structural and floristic differentiation of the vegetation - particularly the vegetation mosaics of the coastal lowlands.

The different rainfall patterns, soil types, drainage, altitude and a complex evolutionary history have combined to produce a wide variety of identifiable rainforest communities.

The material on this page is from 'Repairing the Rainforest' by Dr Steve Goosem and Nigel Tucker. This book is available from the Wet Tropics Management Authority >