Mixed-species plantations: Prospects and challenges

About 2% of English-language literature on plantations deals with mixed-species plantations, but only a tiny proportion (< 0.1%) of industrial plantations are polycultures. Small landholders are more innovative, with 12% of Australia's farm forestry plantations under mixed-species plantings, and 80% of Queensland's farm forestry as polycultures. We examine reasons for this discrepancy, and explore the history, silviculture and economics of polycultures. Financial analyses suggest that a yield stimulus of 10%, depending on product and rotation length, may be sufficient to offset increased costs associated with planting and managing a mixed-species plantation, a stimulus that has been demonstrated in many field trials. We conclude that the main obstacle to commercial uptake of polycultures in industrial plantations may be the lack of operationalscale demonstrations coupled with reliable financial analyses. (c) 2006 Elsevier B.V. All rights reserved.