The Tumut Fragmentation experiment came about when Professor David Lindenmayer was flying from Canberra to Melbourne and was able to see from the air a natural experiment in the pine plantations of the Tumut region. Native forest had been cleared for pine plantation, but the unusual thing was that pockets of native forest had been left and were now 'islands in a sea of pine'. The study sought to assess plant and animal responses to landscape context and forest fragmentation in the Buccleuch State Forest, a 50,000ha plantation of radiata pine (Pinus radiata). Field sites were established in radiata pine stands (40 sites), in large unfragmented forest ('controls', 40 sites) and in the native forest ‘islands’ within pine stands (86 sites).
Large plantations, even of exotic vegetation like radiata pine, can retain some biodiversity value if they contain a mosaic of remnant patches of native vegetation, especially if these are linked by riparian native vegetation. The distance of remnants from large, continuous (potential source) areas appears to be very important for a number of species (eg Agile Antechinus).
Larger patches of remnant vegetation support more native animals than smaller patches. However, an interesting finding was that patches as small as half a hectare support a much higher number of vertebrates than previously realised. These patches of native vegetation are more likely to be occupied by some vertebrate taxa (eg small mammals and arboreal marsupials) than more isolated ones. However, even isolated patches can have significant conservation value for many species and therefore should be conserved.
This research has contributed to the codes of practice for plantation establishment.