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Biodiversity

Biodiversity is the variation of life forms within a given ecosystem, biome or for the entire Earth. Biodiversity is often used as a measure of the health of biological systems. Biodiversity found on Earth today consists of many millions of distinct biological species, the product of four billion years of evolution.

Biodiversity is the foundation for sustainable urban and rural living. It generates the ecosystem processes that regulate air, soil and water quality, maintain soil fertility, and break down domestic, industrial and agricultural wastes. Biodiversity therefore underpins many aspects of daily life.

Forests and biodiversity
Forests are incredibly complex ecosystems that are an integral part of our cultural and spiritual human landscape.

Most biodiversity "hotspots" are located in the tropics and most of them are forests. Undisturbed forests around the world, also know as old growth forests, contain the highest amount of biodiversity of any habitat.

Brazil's Atlantic Forest is considered a hotspot of biodiversity and contains roughly 20,000 plant species, 1350 vertebrates, and millions of insects, about half of which occur nowhere else in the world.

The island of Madagascar including the unique Madagascar dry deciduous forests and lowland rainforests possess a very high ratio of endemic species and biodiversity, since the island separated from mainland Africa 65 million years ago, most of the species and ecosystems have evolved independently producing unique species different from those in other parts of Africa.

In Canada, forests are home to a vast diversity of wildlife - of the estimated 140,000 species in Canada approximately two-thirds are thought to occur in forests. While 94% of Canadian forests are publicly owned, the vast majority of commercially viable crown forest land in Canada is licensed to industry. Industrial forestry traditionally manages forests to maximize the amount of wood coming out of them, and doesn’t pay enough attention to the preservation of old trees, a diversity of species composition, and healthy wildlife populations to ensure that ecosystem functioning is maintained for the long term.

Australian biodiversity rivals any in the world. It is ancient, extensive and unique. Many Australian species and natural communities found nowhere else on Earth; over 80% of mammals, reptiles and flowering plants are endemic (found only in Australia). However, the destruction and fragmentation of habitat, particularly as a result of clearance of vegetation for agriculture, and the impact of feral animals and invasive weeds has had a substantial impact on Australia's biodiversity. Australia has the worst mammal extinction rate in the world. Altogether, 22 mammal species have become extinct since the arrival of European settlers a little more than 200 years ago.

The logging of Australian old growth and high conservation value forests in continues in Tasmania, Victoria and South East New South Wales. This directly threatenws the survival of dozens of endangered species, including the Spotted Tree Frog and Baw Baw Frog, Spot-tailed Quoll, Long-footed Potoroo, Sooty, Powerful, Masked, and Barking Owls, Red-tailed Black Cockatoo, Leadbeaters Possum, Yellow Bellied Glider, Galaxias, Orbost Spiny Crayfish and Strzelecki Burrowing Crayfish in Victoria and the giant Tasmanian wedge-tail eagle, Tasmanian Devil Wielangta stag beetle in Tasmania.

Biodiversity and climate change
Biodiversity around the globe is already under stress from human impacts such as land use change, regulation of streams, soil salinisation, invasive species, over-harvesting of commercially valuable species and changes to fire regimes. Climate change is an additional stress.

While many plants and animals have evolved to cope with large year-to-year climate variability, many terrestrial species have narrow long-term average climate ranges.

Many species and ecosystems could be highly vulnerable to the rapid and sustained increase in long-term average temperatures of 1 or 2°C, projected under climate change scenarios. For, example, climate change modelling indicates that the extent of highland rainforest ecosystems of tropical North Queensland in Australia may decrease by up to 50% with a 1°C increase in temperatures (Pittock, 20031; Hilbert et al. 20012)"

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