Habitat loss has 'domino effect'

University of Queensland, Science Alert 30 Nov 09;

People have cleared more than a quarter of the world's forests and half of its grasslands, according to a paper published today in the Proceedings of the Royal Society by researchers from The University of Queensland and Imperial College London.

The research team also discovered a domino effect to wilderness destruction – that habitat clearance spread most rapidly in natural areas that had already been disturbed.

“A disease-like spread of clearance is bad for biodiversity. A previously intact area of wilderness that we thought was safe can suddenly become vulnerable to rapid decline as clearance of adjacent wilderness begins to threaten the area,” Dr Elizabeth Boakes of Imperial College London, and lead author of the study, said.

Study co-author, Dr Richard Fuller from The Ecology Centre at UQ, said: “Our results underline the importance of conservation in wilderness areas. If we can stop threats penetrating our remaining wildernesses, we should be able to conserve them for the long term.”

The researchers divided the world into 50km x 50km blocks to match preceding model scales which allowed them to compare how habitat clearance had spread over the past 300 years.

“A block of forest or grassland is far more likely to be cleared as soon as a single adjacent block is cleared. Conversely if surrounding habitat remains healthy, it is relatively safe from clearance,” Dr Fuller said.

“Typical reactive conservation measures will often not work because of the scale issue. We need broader instruments such as legislation and land stewardship arrangements that work less intensively but over much larger areas to prevent initial incursions into wildernesses as these can quickly develop into wholesale clearance.”