48 AvailableNew on-lineZealand at: Journal http://www.newzealandecology.org/nzje/ of Ecology, Vol. 34, No. 1, 2010 special issue: Feathers to Fur The ecological transformation of Aotearoa/New Zealand Impacts of introduced deer and extinct moa on New Zealand ecosystems David M. Forsyth1*, Janet M. Wilmshurst2, Robert B. Allen2 and David A. Coomes3 1Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, 123 Brown Street, Heidelberg, Victoria 3084, Australia 2Landcare Research, PO Box 40, Lincoln 7640, New Zealand 3Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB3 2EA, UK *Author for correspondence (Email:
[email protected]) Published on-line: 4 November 2009 Abstract: There has been considerable ongoing debate about the extent to which the impacts of introduced deer on native vegetation have replaced those of moa, and since the 1980s there have been major changes in thinking about the impacts of deer and ratites on ecosystems. Although it has long been known that deer caused a predictable sequence of changes in forest understorey composition, recent work has shown that the foliage of species preferred by deer contains lower concentrations of fibre – and decomposes faster – than avoided species. Analyses of long-term permanent plot data suggest that some preferred species are failing to regenerate in forest types where deer are present. As well as likely altering the long-term biogeochemistry of forest ecosystems, deer have a strong negative effect on the abundance of litter-dwelling macrofauna (most likely through trampling). Estimating the impacts of extinct taxa on an ecosystem has much uncertainty, but recent experiments have shown that extant ratites and deer may have more similar feeding preferences than previously believed.