characteristics in subtropical rainforests By Maina Kariuki* School of Environmental Science and Resources Management, Southern Cross University, P O Box 157, Lismore, 2480, NSW Australia. Email:
[email protected] . Margaret Rolfe Graduate Research College, Southern Cross University, P O Box 157, Lismore, 2480, NSW Australia. R. G. B. Smith Forests New South Wales Northern Research. PO Box J19 Coffs Harbour 2450 J. K. Vanclay School of Environmental Science and Resources Management, Southern Cross University, P O Box 157, Lismore, 2480, NSW Australia. Robert M. Kooyman National Herbarium of NSW, Botanic Gardens Trust, Mrs Macquaries Rd, Sydney, NSW 2000, Australia * Corresponding author We examined tree diameter growth in 20 plots subjected to various disturbance intensities (natural, low, moderate and intensive logging) in a bid to understand the general tree growth responses in relation to habitat characteristics in subtropical rainforests of north-eastern New South Wales, Australia. Species-specific regeneration strategy, maximum size and level of shade tolerance were used to classify species into 5 groups; emergent and shade tolerant main canopy (group 1), shade tolerant mid canopy (2), shade tolerant understoreys (3), moderate shade tolerant (4), and shade intolerant (5) tree species. Data series for trees ≥ 10 cm diameter at 1.3 m above the ground level (dbh) providing observations spanning over 36-years were used in multilevel regression analyses. The results showed that spatial and temporal effects in tree growth at the stand-level are a combination of the differences between species functional-group compositions and environmental gradients. High growth responses were observed in the shade intolerant species while increasing level of shade tolerance and decreasing maximum size decreased trees growth rates.