Rainforest Live '97 Topic Essays from Queensland, Australia Faculty and Student Topic Essays

  From the week ending February 14, 1997

Plant Life of the Rainforest!
by Springer Fyrberg

In tropical rainforests, we find a huge variety of trees. Part of the reason for this is that different species have developed different strategies to meet similar challenges. One of the most critical problems trees face is devising a method to spread, or disperse, their seeds. One strategy that rainforest trees have developed to disperse their seeds is to attract birds by providing tasty fruits. The birds feast on the fruit, seeds and all, and fly away. Later on, those birds deposit the seeds in their droppings, in a new part of the rainforest. If the conditions are right, the seeds can develop into seedlings, and eventually majestic canopy trees.

Strangler figs have evolved into experts at this method of seed dispersal. They grow thousands of small, plump fruits, similar to the figs you might eat, each of which is filled with hundreds of tiny seeds. Those seeds cannot be digested by the birds, but pass right through, and sometimes drop in the branches of some other tree. If the seed falls in just the right spot, they can sprout in the branches of the “host” tree, and begin to send down roots. These roots must sometimes travel more than fifty feet down to reach the soil, but when they do, the strangler fig is all set. It sends down more and more roots which thicken and tighten around the host tree. By the time they have developed into a solid structure, which can support the fig tree, the host tree is usually “strangled” to death! Eventually the dead tree rots away, leaving the fig with a hollow core sometimes big enough to stand in! Because the Strangler Fig seeds are carried by small, flying birds, they are widely spread throughout the forest.

Other trees bear fruit with very large fruit, with just a single seed, or pit. Fruits such as these can only be eaten by very large birds. Australia is home to a very special bird called a cassowary, which is a bit similar to an emu or ostrich, and can stand taller than a full grown human! These birds are very important parts of the rainforest ecology, because only they can spread the large seeds, and ensure survival of trees like the Black Pine or Satin Ash.

Of course, birds are not the only animals in the rainforest who spread seeds. Luckily for humans, we can eat many of the delicious fruits tropical plants produce. The birds will have to share their breakfast of lychees, bananas, passion fruits, and mangoes with me!

 

Tropical Rainforest
by Dr. Tessie Tumaneng, Faculty
Resource Manager

Rainforests refer to closed-canopy forests and particularly consist of different layers of trees of straight trunks, abundant with various epiphytes and lianas, with shrubs and mosses and other plant forms on the ground depending on the moisture level in the habitat. Various kinds of animals, insects and other living things also abound in these kinds of forests. Tropical rainforests occur mainly where there are more or less continuous humid warm climates. In this case, they are referred to as evergreen rainforests. Where there are distinct rainy and dry seasons, they are referred to as monsoon forests, or semi-evergreen. Tropical rainforests are concentrated in South America, Asia and the Pacific (including Australia). They consist only 7% of the world's total land area but they contain more than half of the world's flora and fauna. Rainforests are important in maintaining species diversity, production of trees, improvement of water and soil quality, prevention of flash floods, recreation and ecotourism, wildlife habitat among others.

www.sitesalive.com / Rainforest Live