Tag: Plants

Australia’s Red Centre

As you land at Ayers Rock airport two things  strike you. The first is that the red centre really is red, a deep red that looks like it has been concentrated over time as it bakes in the desert sun. The second, and more surprising, is that it is also green. Despite the low rainfall and high temperatures some species of plant actually appear to thrive here. Whereas there is  only a few shades of red the greens come in all shades.

There are over 400 species of plants in the area around Uluru and Kata Tjuta alone If you include the whole of the red centre of Australia the number is in the thousands. These plants are important to the indigenous aboriginal people who have used them as food, medicine, for making weapons and clothing. Some plants will grow and flower only following desert rain, others are very well adapted to surviving in the hot and dry climate. The following are just three examples of plants found around Uluru and Kings Canyon that demonstrate just how well adapted they are.

Spinifex

A significant contributor to the overall greeness of the desert is spinifex. Spinifex is a grass, a highly adapted grass, that can survive the exceptionally dry conditions. It is incredibly deep rooted which is important in its search for the water table and these roots also spread out laterally. This lateral growth gives stability as the grass helps bind the sandy earth and prevents erosion.

Clumps of spinifex are very common. if you are unlucky to walk through them the leaves are sharp yet they provide shelter for small desert marsupials. As the grass ages the centre dies to leave a ring.

The Desert Oak

The Desert Oak is very common in the area around Uluru. As you move further and further away it gradually disappears from the landscape.

When young it consists of a single stem with little side branching, Its leaves are modified to prevent water loss and it has a very slow growth rate. Much of its growth is going on below ground as the roots grow and spread in search of water. Once the roots reach the water table and there is a sufficient supply of water the tree will begin to produce side branches. The Desert Oak is able to cope with bushfires, only its foliage will burn, the trunk is relatively fire resistant.

Ghost Gum

Eucalyptus trees are very common throughout Australia where they are also known as gum  trees. One species of gum highly adapted for life in an arid climate is the Ghost Gum. So called because its trunk and branches are ghostly white in appearance

In times of severe water shortage the tree can selectively kill off branches to conserve water. As the tree grows these appear black and without any foliage giving the tree a kind of mosaic appearance

New Zealand’s Flora and Fauna

I must confess to being rather ignorant about the flora and fauna of New Zealand before arriving here however it didn’t take very long before we began to realise what a unique country this is.

To understand the uniqueness of the country plants and animals you must first know something about its formation. The supercontinent of Gondawana existed over 500 million years ago and it started to separate around 180 million years ago. This break up formed the parts of the world we today know as Australia, Antarctica, Africa, South America, India and New Zealand. New Zealand became isolated around 90 million years ago and it has been out there on its own ever since. As a result it does not have any native land mammals with the exception of a couple of species of bat. Indeed the first humans did not arrive in New Zealand until the thirteenth century with the arrival of explorers from Polynesia.

Approximately 65 million years ago there was a mass extinction event that wiped out 75% of the plants and animal species on earth, including the dinosaurs. The removal of top predators meant that small mammals could evolve rapidly to fill all the newly created empty habitats. The age of the mammals had begun but New Zealands isolation meant that they couldn’t get there. All land mammals in New Zealand today were introduced by humans. In the absence of native mammals the birds flourished. With no natural predators it didn’t matter if the birds could fly or not so gradually, over time, many lost the ability to fly. Much of the bird population was flightless and ground dwelling.

Human settlers in New Zealand began introducing mammals. Cattle, sheep and goats were highly successful and profitable but other introductions were less so. in 1857 1000 Australian possum were brought to the country for their pelts. By the 1980s their numbers were estimated at around 70 million and the environmental effects disastrous. Possums are carriers of TB .They also grazed on native plants which had no adaptations to grazing and they also ate the eggs and chicks of flightless birds which could not escape them. Stoats and ferrets which were. introduced to try and control rabbits also added to the problem. Now birdsong and native birds in the forests are rare. Control measures are now in place to reduce numbers and there has been some success but there is still a long way to go. Native birds are being reintroduced into areas of forest which have been declared predator free.

Isolation has meant that New Zealand has developed a unique native flora. Most native trees are evergreens, species of deciduous trees having been introduced by settlers. There is a relatively high number of species of fern for a temperate climate. As you drive the west coast rainforests you can not fail to be impressed by the number of ferns and their size. Indeed New Zealand national sports teams have the silver fern as their emblem. Mosses an liverworts also abound. Many plants are larger than similar forms elsewhere. Forests are dense with a large under canopy, it is relatively easy to get lost if you stray from a track in such areas. Some of the forests are old and it is easy to see where the inspiration for the Ents in Peter Jacksons Lord of the Rings came from.