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Ecology, management and conservation in natural and modified habitats
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RESEARCH ARTICLE
Contents Vol 32(5)

Biodiversity and invasive grass species: multiple-use or monoculture?

Keith Ferdinands A B , Kerry Beggs A and Peter Whitehead A
+ Author Affiliations
- Author Affiliations

A Key Centre for Tropical Wildlife Management, Charles Darwin University, Darwin, NT 0909, Australia.

B Corresponding author. Email: keith.ferdinands@cdu.edu.au

Wildlife Research 32(5) 447-457 https://doi.org/10.1071/WR04036
Submitted: 3 May 2004  Accepted: 3 May 2005   Published: 8 August 2005

Abstract

Invasive plants are recognised as a major threat to biodiversity conservation worldwide. Despite this recognition, our understanding of the mechanisms controlling the invasion process and its impact on flora and fauna is often poor. We examined the impact of an invasive aquatic grass species, para grass (Urochloa mutica), on seasonally inundated wetlands in tropical northern Australia. Flora and avifauna were surveyed at sites invaded by para grass and in native vegetation. Spatial information systems were used to design surveys and determine environmental correlates of para grass distribution and so predict the potential future spread of para grass and infer impacts in the absence of control. Where para grass was present the median number of plant taxa was ~75% lower. Few birds showed preference for habitats invaded by para grass, and most birds were associated with areas of native vegetation or other habitats with little or no para grass. The study identified several wetland habitats that are at greater risk of invasion, based on the apparent habitat preferences of para grass. The degradation or loss of some of these ‘at-risk’ habitats, including Oryza meriodionalis grasslands that play an integral role in the wetland food chain, has important ramifications for the levels of biodiversity supported by the wetlands.


Acknowledgments

We thank two anonymous reviewers for constructive reviews of the manuscript. Christine Bach, Jane Hosking, Paul Jonauskas and Robert Townsend provided invaluable advice on many aspects of this project. Some of the avifauna survey data reported here were collected by Christine Bach and Jane Hosking. The Parks and Wildlife Commission NT and the Department of Infrastructure, Planning and Environment provided logistic and financial support for the fieldwork component of the project. Alaric Fisher and John Woinarski provided advice on statistical analysis of avifauna data. We thank the numerous volunteers who provided fieldwork support and the Walker family for allowing access to field sites. This project was funded by the Australian Research Council through the Strategic Partnerships with Industry – Research and Training (SPIRT) program, which provided APAI scholarships for Ferdinands and Beggs.


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