Biodiversity Futures under Alternative Forest Industry Scenarios in North Queensland

North Queensland is a major repository of biodiversity in Australia. From the perspective of industry proponents, the impacts of plantation developments on biodiversity deserve consideration because these impacts are likely to influence public acceptance of proposals and whether proposals can attract environmentally-linked funding and marketing opportunities. At the same time, plantations offer a unique opportunity for broadscale reforestation, and if designed and managed appropriately may be a cost-effective way of restoring biodiversity to cleared land. Plantations may have positive or negative impacts on biodiversity at a range of scales, depending on the species used in plantations, and other aspects of plantation design, management, harvesting and location. This paper examines the potential consequences for biodiversity of a number of broadscale plantation scenarios proposed for cleared rainforest landscapes of the Queensland Wet Tropics. Of the scenarios examined, a mosaic of plantations and restoration plantings was considered to have the highest value for rainforest biota. Three scenarios based on plantations of rainforest trees (monocultures of hoop pine, mixed species plantings and a mosaic of monocultures) were considered to have moderately positive impacts on biodiversity, while plantations of nonrainforest trees (eucalypts and exotic pines) had the least positive consequences for biodiversity in the region. All scenarios potentially have negative impacts on biodiversity, depending on where they are located, and how they are designed and managed. Plantations of exotic rainforest trees (and non-local provenances of native species) have the potential to invade native rainforests. In practice, the ranking of scenarios may vary according to landscape forest cover. Scenarios having the most positive consequences (e.g. a mosaic of plantations and restoration plantings) would be favoured in heavily cleared areas, while scenarios with few negative consequences in rainforest landscapes (e.g. a mosaic of hoop pine plantations and restoration plantings, or plantations of hoop pine, local rainforest species, or even exotic pines) would be favoured for cleared land in well-forested areas. Optimising synergies and managing trade-offs between biodiversity conservation and other objectives of plantations will require investment in large-scale, long-term research, ideally as an integral component of broadscale plantation projects. INTRODUCTION The rainforests and associated forest types of the Queensland Wet Tropics are extraordinarily significant biologically, providing habitat for 25% of Australia’s plants, 35% of