New Zealand forests - background. Native Beetles in an Exotic Landscape Investigating the conservation value of plantation forests in New Zealand

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1 Native Beetles in an Exotic Landscape Investigating the conservation value of plantation forests in New Zealand Lisa Berndt 1, Ecki Brockerhoff 1 and HervÄ Jactel 1 Centre for Sustainable Forest Management, Forest Research, New Zealand INRA, France New Zealand forests - background Loss and fragmentation of natural forest habitat only 1/3 of NZ original forests remain Lowland areas hardest hit (eg Canterbury Plains) Separation of production and conservation values Pre-human land cover Loss of native land cover Leathwick et al. (004) Land Environments of NZ Plantation forestry in NZ What can existing plantation forestry contribute to conservation? 1.8 million hectares Mostly exotic species Pinus radiata Production only limited recreation and conservation values Public view as a monocultural wasteland, low biodiversity Research aims Compare the carabid beetle assemblage of a native forest remnant with that of an exotic pine plantation and exotic grassland. Canterbury Plains Majority is sheep or cattle pasture, or grain Less than 0.1% of the Plains supports native vegetation Around % in plantation forest Habitat types: Native kanuka low forest (Kunzea ericoides) Old pine plantation Young pine plantation Exotic grassland 1

2 Eyrewell plantation Native habitat at Eyrewell (Kunzea ericoides) low forest previously covered most of the Eyrewell region Periodic disturbance by fire Now less than 100 ha of kanuka habitat remains on the Canterbury Plains Most of this is unprotected Approx ha, mostly Pinus radiata First planted between 196 and 1935 Methods: Pitfall traps in forest and surrounding habitats over three summers (000-03) - Eyrewell Scientific Reserve.3 ha of kanuka low forest and shrubland Western end of Eyrewell pine forest Fenced since 1970 Old pine 4-7 years old trees To be harvested at 8 years Most stands have an understorey of kanuka and gorse (Ulex europaeus) Young pine 4 year old trees Open habitat, before canopy closure Woody debris with exotic grasses and weeds Pasture edges and fallow ground Adjacent to pine forest Sheep and dairy

3 Results: Relative abundance Species richness (rarefaction) Relative abundance (beetles/100 trap days) c Exotic Native c Old Pine Young Pine Habitat a b Species Old Pine 4 Young Pine Individuals Ordination Constrained Principle Co-ordinate Analysis (CAP) Axis Axis 1 Habitat Old pine Young pine Species Old Pine Young Pine Native Megadromus antarcticus Exotic Hypharpax sp. 'gm' Species Old Pine Young Pine NativeMegadromus antarcticus ExoticHypharpax sp. 'gm' Species Old Pine Young Pine NativeMegadromus antarcticus ExoticHypharpax sp. 'gm' 3

4 K e y ( b e e t l epse r1 0 0trapd a y s ) Species antarcticus E x o t i chypharpax sp. 'gm' < > 10 Old Pine Young Pine Pasture N a t i v e Megadromus Known H. brevicula locations 1950 s and 60 s specimens Collected during the present study ( ) Collected since 003 (not included in previous data) Eyrewell plantation provides: A diverse range of environments, reflecting the history of disturbance of the area Habitat for many native carabid species Without the plantation in the landscape at Eyrewell, the carabid fauna of the area would be poorer, and a threatened species may become extinct. Classified as nationally critical and under acute threat of extinction Ten specimens known to science All caught in Eyrewell Forest pine plantation Summary Native kanuka habitat had highest species richness, including forest specialist spp. Generalist species dominant, reflecting history of disturbance Old pine carabid fauna most similar to kanuka carabids Exotic carabids abundant in open habitats young pine and grassland Eyrewell plantation forest is the only known habitat for a threatened carabid species Conclusions Exotic plantations can: support native plant and animal communities, including some rare species provide a more diverse, less disturbed habitat than other production landscapes (eg arable crops, pasture) act as buffer or corridor connecting native forest remnants be a compromise between production and conservation in areas where native habitat is rare 4

5 Acknowledgements FRST, Carter Holt Harvey, Department of Conservation, and private landowners. Peter Johns, Rowan Emberson, Steve Pawson, Tanja Weis, Alan Leckie, Sylvia Maclaren, Janette Beaton. 5