Thursday, April 19, 2007

Gondwana Link

One of my favourite places to visit in Australia is the southwest corner of the country. It has a fantastic variety of rare and interesting avifauna and some of the best natural wildflower displays I have seen. The area around Albany and particularly Two Peoples Bay interest me but the whole south west is a great place to visit.

Gondwana Link is an ambitious ecological program in southwest Western Australia that seeks to protect, manage and restore bushland in a 1000 kilometre long pathway, from the wet forests of the Australia's south west corner to the woodlands and mallee bordering the Nullarbor Plain. As part of this program Bush Heritage, Greening Australia and The Nature Conservancy have been raising funds, buying strategic properties, managing the bushland and re-vegetating large areas of cleared land. The idea is to increase ecological resilience to such events as climate change by providing a connected corridor of habitat that permits animal and plant relocations.

South-western Western Australia (SWWA) is (following the classification of Norman Myers) Australia’s single biodiversity hotspot. To qualify as a hotspot, a region must meet two criteria: it must contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics, and it has to have lost at least 70% of its original habitat. In fact this area contains more than 10,000 plant and animal species – many of them endemic to this region. A great deal of native vegetation has been lost to land clearing and even fertile agricultural land is being lost to salinity. The promise is that improved conservation of landscapes will help conserve species and improve agricultural productivity.

The project itself commenced in 2002 and when complete will link 146,000 square kilometres of reconnected and restored land. Yesterday the Australian Government announced the 946 hectare Monjebup Creek Reserve would join the Peniup, Nowanup, Chereninup Creek and Yarrabee Westfarmers Reserves as part of the Gondwana Link project.

The southwest region as a whole is vulnerable to climate change. It is under significant stress due to poor land management. Land clearing has created salinity problems and impacted on the region’s biodiversity. These stresses have increased the region’s sensitivity to further climate–related changes: See Allen Consulting Group (2005).

Furthermore, SWWA has already experienced climate changes. This region has seen a 10-20 per cent decrease in its winter rainfall over the last 30 years and in tandem with this, temperatures have also increased substantially over the last half century.

Studies by the Indian Ocean Climate Initiative (IOCI) have indicated that the decrease in rainfall has been accompanied, and been associated with a change in the large scale global atmospheric circulation, which is consistent with changes projected by global climate models incorporating anthropogenic forcing. There is insufficient evidence to indicate that the enhanced greenhouse effect alone is responsible for the shift in rainfall levels and temperature patterns. Most likely, the climate changes are a function of both natural variability and anthropogenic change. Nevertheless, these climate pressures remain, and science suggests that they are likely to continue into the future as on overlay on ‘natural’ occurrences.

In work that I am now undertaking I will look at the implications of the Gondwana Link project in terms of its capacity for assisting in dealing with climate change. If the main relocation consequences of global warming are to encourage species south to cooler climates then species in the northern extremity of the project area will head south or south east. One difficulty is that numerous endangered species in this zone lie on its southern extremity and they cannot relocate into the ocean. For example, heathland systems in this area exhibit high levels of biodiversity and are already under pressure from habitat fragmentation and salinity. They are trapped from further southward migration as temperatures warm. Of course connecting up areas of disjoint native habitat by means of corridors will improve environmental resilience generally but this latter concern is a real one.

Some useful links: Official website; Bush Heritage News and here; The Nature Consultancy and Greening Australia. The Western Australian Greenhouse Strategy.

It is worth noting that Bush Heritage is also developing a Kosciuszko-to-coast (K2C) project in Southern NSW that will connect the Australian Alps with remnant bushland on the coastal ranges to the east. Scottsdale Reserve has already been purchased by Bush Heritage. It covers 1328 hectares of the Murrumbidgee River valley 12 kilometres north of Bredbo in New South Wales, a 45-minute drive south of Canberra. It rises in elevation from a large fertile grassy valley with rich alluvial soils, through dry sclerophyll woodlands and onto a grassy woodland plateau. This plateau drops steeply into the Murrumbidgee River itself.

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