There are many different types of rainforests and various ways of defining a rainforest, however the most useful definition is a forest with a closed canopy of trees, more than one layer of trees and other foliage including vines and epiphytes.
Northern NSW has various different types of rainforests, from upland and lowland subtropical rainforests, through littoral or coastal rainforests, to Palm Forest rainforests. Some of the most interesting plants in these forests include the Palm, Fern and Epiphyte species. All of these plant species grow best in full shade, with high humidity and regular rainfall. They are adapted to grow under a full canopy of trees and add dimension and beauty to the rainforest.
Palms of Northern NSW Rainforests
Palms are not actually considered to be trees, as they are more closely related to grass and bamboo. Palms have fibrous root systems and have a different internal structure to garden trees. Instead of having the conducting tissues of the vascular system being regularly arranged as in most plants, palms have these tissues scattered throughout the stem. This means that palms cannot be ring-barked like other trees.
In northern NSW rainforests there are many different palms, however the major species are Bangalow Palms (Archontophoenix cunninghamiana), Alexandria Palms (Archontophoenix alexandrae) and Cabbage Palms (Livistona australis). These are all solitary palms, not clumping palms. Banglow palms are the most dominate species in northern NSW and can be found forming dense stands in the mountainous areas. Cabbage Palms are usually only found in lowland areas and in swamp forests. All species need a lot of water to grow, and so are most commonly found beside creeks, rivers and in areas of poor drainage such as swamps. Bangalow palms grow to a height of between 10 and 25m once they are full-grown.
Amazing Facts About Ferns
Fern species are very interesting plants, as they do not produce any flowers or any seeds. Instead they reproduce by way of tiny spores that are enclosed in spore cases. These spores can be on the underside of mature fronds or other leafy parts of the plant. Some ferns have edible parts.
Northern NSW rainforests have various different species of fern, ranging from ground-covers to the large Tree Ferns. These tree ferns can reach 5m in height and have large feathery fronds. The most common tree fern is the Scaly Tree Fern (Cyathea Cooperi), which is a very quick-growing fern and will reach over 2m in only a few years of growth. Other tree ferns in this area include the Rough Tree Fern (Cyathea australis), and the Prickly Tree Fern (Cyathea leichhardtiana).
The Beautiful Epiphytes of the Northern NSW Rainforests
Epiphytes are plants that grow supported on another plant, usually on the trunks of tall rainforest trees. Some of these plants are also able to grow on rocks or dead tree stumps. The three most common epiphytes in northern NSW are also ferns and so reproduce from spores.
Both elkhorn (Platycerium bifurcatum) and staghorn (Platycerium superbum) ferns have fronds that resemble deer antlers and are very common in this part of Australia. Elkhorn ferns grow multiple plants in the same spot and so form large clumps. Large clumps of elkhorn fern produce a perfect environment for other epiphytes such as orchids. Elkhorn’s produce two different sorts of fronds and only one sort contains spores.
Staghorn ferns do not form clumps. Instead the individual plants continue to grow bigger over the years and can reach large sizes. Like the elkhorns, staghorn ferns produce two different types of fronds, the infertile ones cling to the trees, while the fronds that contain spores hang down from the middle of the plant.
A very common sight in the rainforests of northern NSW is the Birds Nest Fern (Asplenium australasicum), which often grows in large rainforest trees or on dead tree stumps. This is a lovely fern, with large fronds that grow in a circle around a hollow centre. The centre part of the fern is invariably filled with leaf-litter from the trees around and looks very much like a large birds nest.
References:
- Blombery, A.M., Australian Native Plants, 1967, Angus & Robertson, Australia.
- McFarlane, A., Successful Gardening in Warm Climates, 2001, ABC Books, Sydney.
- The Big Scrub Landcare Group, Subtropical Rainforest Restoration: A practical manual and data source for landcare groups, land managers and rainforest regenerators, 2nd Edition, 2005, Bangalow, NSW.
Nina Boddenberg - Nina is a writer from Australia, who is currently building her own home and planting a large organic and permaculture garden. Nina ...
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