November 20th 2003
Why the Island's lowlands are "critical"
Landscape Ecologist and Island resident Margy Gaynor has been an articulate contributor to debate over major developments threatening the Island's World Heritage natural values. In the following article Margy outlines some of the reasons why the Island's populated lowlands are so important to the overall makeup of the Island's ecology. Ed.
Magnetic Island & its World Heritage Urban Lowlands: the dilemma of development in critical habitat
Maggie Island is part of the Great Barrier Reef World Heritage Area, which was proclaimed in 1981. As such, all land on the island has World Heritage status including the extensive upland National Park, all of the urban lowlands, and the substantial tracts of Unallocated State Land (USL) that surround the urban areas and provide a buffer for the National Park.
It is frequently commented that the island's National Park is extensive, and that the lowlands should therefore be open to development. A common complaint is, "Look at all the National Park - haven't the greenies got enough?", and superficially this would seem to be the case. A little knowledge of landscape ecology of the Dry Tropics provides a vastly different picture. And the island's unique place in the World Heritage Area adds to the urgency for far more sensitive development of the urban lowlands.
Maggie Island is the northern-most outlier of an extensive area known as the Brigalow Belt Bioregion that sweeps north from NSW, covering large areas inland from the Pacific coast. This bioregion emerges on the coast in the Rockhampton area, and again on the Bowen-Townsville plains. The bioregion's northern reaches are known as the Dry Tropics, and unlike much wetter coastal regions and offshore islands immediately to the north and south of Magnetic Island, the Dry Tropics features intense Dry Seasons and unreliable Wet Seasons. Hence Maggie's harsh dry landscapes and comparatively sparse scrubby vegetation -- so typical of the Dry Tropics.
Wildlife in the Dry Tropics absolutely depends on Dry Season refuges for survival -- particularly the watercourses and wetlands, and the vegetation (riparian vegetation) that these support. Landscape features and refuges which are essential for the survival of wildlife are known as critical habitat. Unfortunately, most of the island's critical habitat is located outside the National Park, on the urban lowlands.
Our creeks, even when not flowing, provide deeper, richer soils which stay damp for a long time -- refuge for burrowing frogs. The vegetation along watercourses has a distinctive species composition not found elsewhere, and provides a variety of foods and habitats largely absent from the national park. Many riparian plant species come to fruit late in the Dry Season when other foods sources have died off (eg the native olives that fruit late in the season when the migratory Torres Strait pigeons arrive for breeding). On the urban lowland plains, trees tend to be older and larger than further up into the hills -- they have a much more important role as home for hollow dwelling animals (eg possums, insectivorous bats etc) and birds (eg parrots) than the more exposed and stunted woodlands in the National Parks. And the undergrowth along the creeks is home for numerous birds, butterflies, reptiles and insects -- and provides a natural protective corridor for wildlife moving through the island's landscapes. Lowland habitat also has much more protection from the weather, and fires.
In the past two or three years development of the island's "undiscovered" urban lowlands has accelerated, with some extremely alarming consequences. Many natural watercourses and swampy areas have been altered to accommodate building projects, with the destruction of riparian vegetation and the infilling of natural seasonal wetlands (eg works in 2001 to an un-named creek in the southern reaches of Nelly Bay -- to realign the creek and form a water feature for some planned units -- eliminated the last patch of vine thicket west of Sooning St in this area, and destroyed the only continuous wildlife corridor that connected the beach to the uplands in this part of Nelly Bay. These works also destroyed a large number of animals and breeding sites that were on the site). Another very alarming trend is the destruction of large old lowland trees and the continuity of native undergrowth that is vital for the persistence of our wildlife species. The impact on wildlife may only become obvious in future years when breeding and/or rearing of young becomes impossible for displaced wildlife.
When this pattern of events is viewed in the larger regional context, the picture becomes even more grim. The development of the coastal plains in the Townsville regions has seen the decline of wildlife species throughout this area. Maggie Island has an extremely important role in regional conservation ie as a relatively natural area where wildlife species typical of the region are given protection. This is impossible if the urban lowlands are open to intensive development, as is planned under the current and future town planning schemes.
Magnetic is the only far-northern dry tropics island - the next occurring off Rockhampton some 700kms th the south. In combination with a specific geological type (Magnetic Island granite), the Island's ecological make-up is the only one of its kind in the great Barrier Reef World Heritage Area. The loss of its lowlands would eliminate a unique biota (particular range of animals and plants to that area) from the World Heritage Area -- something that should not occur under the agreements and legislation that supposedly protect this World Heritage Area.
There are development solutions for the island's urban lowlands -- but these require that practical landscape ecology solutions are interwoven with development planning. And essential to this is town planning that insists on low density development, the protection of vital landscape features and the retention of native bush.
Our local authorities, though well informed of this situation, are truly heading in the unsustainable direction -- and the losses are predictable. But it can be very different with committed leadership and some sensitive planning.