First of all, let me wish Voyager Online a happy tenth birthday. May it enjoy many more…

Now, it may be a cliché, but I am Green by name and green by nature. I have had a deep and abiding love for the natural environment all my life, and I am sorry that it has gone ‘out of fashion’ to be a tree-hugger. In recent years, society seems to be taking the attitude that the forests, grasslands, reefs, deserts and other wild places can take care of themselves.

This is not so.

If you study any recent satellite photographs, you can see the destruction that is taking place all over the planet. Closer to home, there is massive degradation to the Australian environment in a daily basis, from the logging of old growth forests in Tasmania to the trash polluting the Great Barrier Reef. And don’t think it can’t effect you… human beings are part of this environment.

The final collapse of our environment will kill off everything. Oh, life on Earth might reconstruct itself from the surviving remains of this cycle… but there won’t be human beings around to see it happen.

Trees play a large part in the structure in many common environmental types, such as rainforests and temperate woodlands. In the last few decades, there have been an increasing number of tree extinctions. The loss of vital biodiversity in so many places around the world is happening as I write.

Tree Extinction

As a Queenslander, I’ll focus on my state first…but the statistics are similar all over Australia. To put it bluntly, about thirteen percent of Queensland’s native plant species are rare or threatened.

Twenty-seven plants are presumed extinct, 149 species are endangered, 279 are vulnerable, and 696 are considered rare. These plants are in danger of extinction in the next 10–50 years unless action is taken to reverse their decline.

Triunia robusta, a small rainforest tree related to the macadamia nut tree, was presumed extinct until re-collected near Nambour in 1989. This tree has since been found in two other small rainforest remnants on the Sunshine Coast, but is still considered endangered. This tree has not been propagated successfully.

Queensland's floral emblem, the Cooktown orchid, is considered vulnerable. A climbing palm, Calamus aruensis, found only in monsoon rainforest pockets of the far North Cape York Peninsula, is listed as rare. Apart from the obvious threats, caused by vegetation destruction such as logging and clearing, plant collecting is the greatest threat to attractive rare and threatened species. In addition, the ravages caused by the introduction of competing non-native species, tree diseases and pests, like the Lantana, can’t be ignored.

The same process is happening in every state of Australia, including Tasmania. There just isn’t room enough to list the major trees species vulnerable in every state.

It isn’t just Australia that is suffering from tree extinction. The New Zealand Pohutukawa Tree, Metrosideros excelsa, is threatened by extinction. A major culprit is the introduced pest, the Australian Brushtail Possum, which has an appetite for the leaves, buds, and young shoots of the Pohutukawa. Possums damage both adult trees and seedlings, so that most surviving Pohutukawa trees are the oldest, toughest specimens of more than 200 years of age.

The New Zealand Cabbage tree is also at risk.

In America, the temperate forests are rapidly changing in composition, due to the rapid extinction of the American chestnut tree, Castanea dentata, and the Elm, Ulmus americana. Both these trees are dying due to fungal diseases, the Chestnut Blight and the Dutch Elm disease.

The Chestnut Blight was first detected in 1904, when curators of the Bronx Zoo in New York noticed an unusual malady afflicting the magnificent chestnut trees lining the avenues of the zoo. Symptoms of this malady included wilting leaves, large cankers with rupturing bark, sprouts below the cankers and shortly thereafter, death of the tree's trunk and upper limbs. It has been estimated that 3.5 billion trees were lost in the forty year span from 1910 to 1950. Over three and a half million hectares of land were stripped of chestnut trees, the enormous tree extinction caused by a fungus, Cryphonectria parasitica. Since its sudden disappearance from eastern forests, no other tree has filled its niche, and the ecosystem has teetered on instability ever since.

Dutch Elm Disease was first found in the United States in Ohio in 1930. It has now spread throughout North America and has destroyed over half the elm trees in the northern United States. The disease has been reported in all states except the desert Southwest. Dutch elm disease is caused by the fungus, Ophiostoma ulmi, which is transmitted by two species of bark beetles or by root grafting. Once the fungus is established within a tree, it spreads rapidly via the water-conducting vessels. The tree forms gums within these vessels in response to the presence of the fungus, causing the tree to wilt and eventually die.

As you can see, tree extinction is worldwide problem. You can help prevent this disaster-in-the-making. Buy recycled wood and paper products when they are available…and write to your environmental minister.

Hypatia of Alexandria
A.D. 370 – 415

Born in Alexandria in A.D. 370, Hypatia was born to be an intellectual. Her father, Theon, was a mathematician and astronomer at the Museum at Alexandria, and Hypatia was his prize pupil. She didn’t just study under her father; she also studied in Athens and Italy. Eventually, she became a lecturer and writer in the fields of mathematics, philosophy, astronomy, and mechanics. Her classes were attended by students from throughout the known world, and her treatise on algebra, Arithmetica, was a thirteen-volume definitive study. Hypatia became head of the Platonist school at Alexandria in about 400 AD. There she lectured on mathematics and philosophy, in particular teaching the philosophy of Neoplatonism.

Practical technology was Hypatia's main interest, which led to her invention of the pane astrolabe, used to measure the positions of the sun. Hypatia perfected the astrolabe to the point where it could accurately solve problems in spherical astronomy. She also invented a device for measuring the level of water, as well as the hydrometer. Her hydrometer was a sealed tube about the size of a flute, weighted at one end; the depth to which the hydrometer sank in a particular liquid gave a reading on the substance’s specific gravity.

Alas, her obvious intellect made her an enemy of the Christian Church. Hypatia came to symbolise learning and science, which the early Christians identified with paganism. She was murdered by Christians who felt threatened by her scholarship, learning, and depth of scientific knowledge. Whatever the precise motivation for the murder, soon afterward many scholars left the city of Alexandria, and this marked the beginning of the decline of Alexandria as a major centre of ancient learning.

Concept of the Month
Key Species

A key species is one that is essential to the survival of a specific environment. Take a pine forest…the obvious botanical key species is the pine tree; in a reef, the key species is an animal, the coral, and so forth and so on. Sometimes there may be more than one key species, and in other cases, there may be a whole cluster of different animals and plants that interact to form a key group. A good example of a group interaction is that of the bears and the salmon and the Northern temperate forests: the biodiversity of these forests is dependant on upon the yearly salmon run, as bears eating the salmon recycle the nutrients as bowel movements in the forest, increasing soil fertility; in other words, that environment is dependant on the bears defecating in the woods.