Flora of Lamington

Influencing Factors

There are many factors which influence the distribution and species composition of plant communities.

In general terms these are: soil type, altitude, rainfall, aspect, slope, fire.

It is more commonly a combination of these factors rather than any individual one which will decide the type and composition of a given community. However, where several factors remain constant (e.g. soil type, altitude and rainfall), one particular factor may have a profound influence (e.g. aspect).

Soils

The acid volcanic soils (ie. rhyolite, trachyte) which are relatively low in plant nutrients usually support open forests, woodlands and shrublands. Some open forest types have shrub and lower tree layers of rainforest species. These communities are often called `wet sclerophyll forests' or `transition forests'. The less complex rainforest communities also occur on these soils, often where nutrient enrichment occurs through erosion from nearby areas of basalt soils (e.g. `warm temperate rainforest' near Nagarigoon Clearing). Basalt soils, which are richer in nutrients than rhyolite, support most of the complex rainforest types within the park. Where open forest occurs on basalt soils, it typically has a grassy rather than shrubby understorey.

Altitude

With an approximate range of 180m to 1200m above sea level within the park, altitude plays a major part in determining composition and structure of plant communities. Cooler temperatures and increased moisture levels at high altitudes tend to favour species adapted to these conditions (the `cool temperate' species such as Antarctic beech). As a general rule, species diversity and structural complexity decrease as altitude increases.

Rainfall and aspect

With the predominant rain-bearing winds in summer being south-easterly, the areas to the north and west of the border peaks are in a pronounced rainshadow. Rainfall on the border peaks (e.g. Mounts Hobwee, Merino and Wanungara) is probably about 2 500mm per annum. At Binna Burra, this figure decreases to 1 500mm and to the west is lower still.

North and west-facing slopes are prone to more drying winds and are warmer than those with a southerly aspect due to the northerly track of the winter sun.

Slope

Affects soil drainage and thus the distribution of moisture-loving plants. this explains, in part, why species normally associated with rainforest may be found along gullies in quiet dry areas. Soil moisture along these drainage lines is much higher than surrounding areas.

Fire

Frequent fires (e.g. 0 to 5 year cycle) mitigate against the reproduction of many trees and shrubs, particularly rainforest species. These plants are not adapted to fires and many require a longer period to produce seed. In areas subject to regular burning, grasses tend to dominate the lower stratum.

Fauna of Lamington

Lamington showcases some impressive examples of “true songbirds” — an ancient group of birds, many of which have melodious calls. Songbirds were originally thought to have evolved in the Northern Hemisphere, later spreading south. However, recent DNA sampling and finds of fossilised songbird bones (dating back 55 million years at Riversleigh in Queensland) suggest songbird groups evolved in the Southern Hemisphere, and spread north.

You can still see and hear some of these ancient songbirds. Lamington National Park is home to various species recognised for their world heritage significance. Examples include the satin bowerbird, eastern bristlebird, rufous scrub-bird, red-browed treecreeper and Albert’s lyrebird.

As part of the CERRA World Heritage area, Lamington is an extremely important refuge for many kinds of animals. These range from several species of earthworm found nowhere else in the world, and the beautiful Richmond birdwing butterfly, to endangered birds such as the eastern bristlebird and mammals, including the spotted quoll. Lamington plays a vital role in protecting this rich diversity of globally significant wildlife.

With more than 1700 flowering plants and 500 vertebrate animals in the CERRA World Heritage area, Lamington protects about 58 plants and more than 22 animals classed as vulnerable, rare or threatened with extinction. Countless numbers of invertebrates and plants, particularly smaller ones, are yet to be discovered.

This natural wealth is supported by many different habitats — all crucial in sustaining many of the last remnants of our natural heritage. Without this national park, many more species would have disappeared or be poised on the brink of extinction.