SydneySCIENCE Highlights

Living with a changing environment: keeping biodiversity alive

The overlap of urban and bush environments is changing the face of Australia. On roadsides across the nation small sections of vegetation have sprung up in attempts to green our cities and suburbs, whilst roads cut swathes through bushlands creating pockets of wilderness.

Dr Dieter Hochuli, a community ecologist, hopes to understand the diversity of these bushland remnants and encourage appropriate management of these isolated pockets of wilderness. “Conserving remnant vegetation is crucial if we are to maintain the quality of life for the 60 per cent of humans who now live in cities, and to protect total biodiversity,” says Hochuli.

Sydney Science - Biodiversity

The remains of these ecosystems often experience a high level of damage before restoration is attempted. With low ecological integrity, they no longer support a dynamic and functional set of interactions between species of plants, insects and their predators.

“Plant-insect interactions are a compelling indicator of structural and functional changes in the ecology of fragmented and disturbed landscapes,” explains Hochuli. “Ants, for example, have a significant influence on abundance of flowering plants in arid and grassy habitats through their seed harvesting and dispersing activities.”

This interdependence between insects and plants may have startling ramifications. Some insects have specific relationships with endangered plants and there is a high possibility that the loss of these endangered plants may result in insect coextinction. Hochuli uses his detailed understanding of insect-plant interactions, the chemical and structural properties of plants, the composition of seeds and seed products, and the traits of flowers, to identify the future of these species endangered by association.

With this in mind Hochuli hopes to encourage communities to have realistic expectations about the outcomes of their restoration processes, particularly the number of species that will return and how much of the degradation can be reversed. “Management styles are a big determinant of the success of any restoration process. Intensive management is attractive because improvements in plant life appear quickly, however it is important to balance these results with restoration of insect processes that will help sustain the vegetation in the long run.”

Stretching his reach beyond insects, Hochuli hopes to uncover the secrets of spider survival on unforgiving rock outcrops. Exposed to uninterrupted sun and with little water these ecosystems are on the edge of liveable habitats. Overrun with opportunistic and predatory species, which hope to outlive the scorching heat and each other, this extreme ecosystem is next on Hochuli’s agenda.

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