Regeneration patterns in southern rata (Metrosideros umbellata) — kamahi (Weinmannia racemosa) forest in central Westland, New Zealand

Abstract

The regeneration modes of the dominant tree species, in the highland conifer-broadleaved forests of central Westland, South Island, New Zealand especially southern rata (Metrosideros umbellata) and kamahi (Weinmannia racemosa), are inferred from detailed analyses of stand structures in the Taramakau area. Both species regenerate intermittently and sparsely beneath canopy gaps in old-growth stands as well as abundantly on sites devastated by extensive natural disturbances such as landslides. The numerous evenaged rata-kamahi stands in Westland reflect the importance of the catastrophic regeneration mode for these 2 species. The eventual synchronous senescence of many of the trees which established at approximately the same time on sites bared by natural disturbances may be an important contributory factor in the canopy tree mortality which is widespread in the region.

Keywords:

• Solanum laciniatum
• plant tissue culture
• in vitro culture
• micropropagation
• callus growth
• callus organogenesis
• leaf culture
• shoot culture
• apical meristem-tip culture
• auxin/cytokinin interaction