Indirect estimation of gorse and broom ‘non-forest land’ to ‘forest land’ transition final report / prepared for Gerald Rys, Science Policy Group by Fiona Carswell, Norman Mason, Robert Holdaway, Larry Burrows, Ian Payton, Anne Sutherland, Robbie Price, Landcare Research; Grant Pearce, Oliver Corich-Hermans, Scion; Peter Williams, Ecological Consultant.