A Rainforest Walk Primary

Although not growing as a strangler here, this plant is capable of such growth in natural rainforest. The twisted pattern of the trunk and aerial roots gives an idea of its ability to encircle and kill a host tree.

Stranglers often start their life high in the upper canopy from seed dropped by fruit eating birds, possums or bats. Up high, the seedling grows quickly because of the more readily available sunlight.

Strangler figs can kill the host tree by squeezing its trunk, cutting out the sunlight and competing for nutrients from the soil. Young healthy host trees may outgrow the strangler.

The visible roots growing directly off the trunk indicates rainforest air is very moist.

Before moving into the clump of trees find a sunny open space and ask the students to note factors of the climate such as temperature, sunlight, wind and humidity.  Once under the trees they will feel a reduction in the temperature, light and wind.  An increase in humidity would be harder to notice. 

Such trees form a canopy or roof to the rainforest which helps create the climate suitable for the understorey plants below.

The large buttress roots help support the tree, absorb nutrients (generally found only near the surface of rainforest soils) and take in oxygen.

Removal of such trees and the subsequent loss of soil binding roots can lead to large scale erosion in these high rainfall areas without canopy protection.

Hundreds of epiphytic plants living on such trees may also be lost when just one large canopy tree is removed.

The Kauri Pine is inside the Botanic Garden to the right of the Conservatory as you face the northern entrance.  As in a rainforest it appears to emerge from the canopy below.

The tall straight trunk of the Kauri Pine, branches spreading and covered with leaves only at the top, is ideally suited to maximising light capture.

Unlike many flowering plants that have their flowers displayed above the leaves, this plant has yellow flowers on the stem near the ground. At some times of the year only the brown, dead flower clusters may be visible. Insects that live on the ground probably pollinate this plant. A weevil is one known pollinator.

The narrow straight trunk, attractive bamboo-like rings and strength meant thousands of these small palms were harvested during World War 1 to make walking sticks for returned wounded soldiers. A comfortable handgrip was carved from the compact root ball found underground at the base of the stem.

The small cabbage formed at the growing tip is edible as are the ripe small red fruits.

The fishtail shape of the leaves gives this palm its common name. It is capable of reaching 27 metres, the same height as the tallest part of the Conservatory.

As it grows and spreads it will increasingly shade the understorey below providing a habitat for a wider range of plants.

Climbers are a common part of the rainforest, expending less energy to reach the light at the upper canopy than trunk building trees.

The Scindapsus is using its roots to climb the trunk of the Palm tree.  Another climber on the trunk uses a spiralling stem, while to the right is a climbing palm which uses sharp, backward pointing spines along the leaf mid rip to pull itself up into the canopy.

Climbers may eventually compete with the trees that support them for light, water and mineral nutrients. 

Large woody climbers are called lianas and may run for a kilometre in length through the rainforest.

The fibrous material surrounding the coconut seed is used in the manufacture of coir matting.  The large leaves are often used to construct a thatched roof for tropical huts.

Almost every part of the coconut is used in some way, cooking, sap making, cosmetics, the finest medicinal charcoal, drinks, etc.

A dwarf Coconut Palm can be seen opposite to the coconut just across the short exit pathway.

Epiphytes such as this are prolific in the rainforest, growing on the trunks of larger trees without harming them.

The spongy base, which resembles a bird’s nest, has fibrous material capable of trapping and holding water.

The funnel-like display of leaves channels water and debris falling from above to the centre of the plant.

When decomposed the debris or food leftovers brought into the centre of the plant can also be a source of mineral nutrition.

Numerous small invertebrates and various stages of decaying leaves can be seen on the ground at this spot.

Large amounts of dead leaves, flowers, fruits and branches are shed from the rainforest canopy each year, up to 8-10 tonnes/hectare annually.  This litter is decomposed by small insects and fungi, which quickly return nutrients to the soil for the plants to re-use.

This process is rapid due to the warm, moist conditions on the forest floor.

This thin, recycled surface layer of nutrients is vital to the rapid growth of rainforest plants yet is quickly leached away and lost when the forest is cleared.

Rainforests are constantly warm and wet. Plants have different features to keep dry and prevent fungi from growing and killing the leaf.

Find leaves in this area with the following features deigned to quickly get rid of water:

¨      a waterproof waxy coating

¨      leaves on an angle

¨      drip tips at the bottom of the leaf.

These structures are best seen on new complete leaves.

This plant can be found at two locations, please refer to map.

The attractive, furry red flowers and cat tail shape give the plant its common name of Red Hot Cat Tails. Rainforests are warm all the time, so many plants flower throughout the year.

This station is a chance for students to enjoy the diversity of living leaf designs to be found in rainforests. From the upper walkway many attractive and diverse leaf shapes are evident.  In general the leaves of the rainforest plants tend to be large and dark green in colour in order to maximise light capture.

This is the most common of native bananas with clumping stems to about five metres.  The female part of the flower develops into finger-like bananas, which yellow when ripe. Wild bananas are not generally eaten because they have little flesh or flavour and are full of 4 millimetre long seeds.

Such wild plants are important as they maintain the “wild” genes, which may be called upon in the future, should new pests and diseases threaten our cultivated species that are grown in farms.  Farm grown bananas have no seeds and are full of tasty fruit.

Encourage students to find the largest leaves near this station. Living in the dark on the rainforest floor many understory rainforest plants have large, water-repellent leaves. The large leaf surface area is designed to maximise the available light for plant growth. Both large and small veins prevent paper-thin leaves from flopping down.

Feel the underside of the leaves, they are soft and velvety. They feel this way because of fine invisible hairs. Apart from feeling nice, the hairs may protect the plant from leaf-eating insects or from losing too much water.