COARSE WOODY DEBRIS IN OLD-GROWTH TEMPERATE BEECH (NOTHOFAGUS) FORESTS OF NEW-ZEALAND

The volume, biomass, and carbon and nitrogen content of coarse woody d ebris were measured on three 1-ha reference plots in old-growth Nothof agus fusca (Hook. f.) Oerst. - Nothofagus menziesii (Hook. f.) Oerst. forest on the South island of New Zealand. Two decay sequences for log s and one for standing dead trees (snags) were recognised from two-way indicator species analysis (TWINSPAN) Of UP to 30 variables related t o physical characteristics and structural integrity. Wood volume (up t o 800 m(3).ha(-1)) and biomass were high (up to 300 Mg.ha(-1)), and th e inside-out decay sequence from heartwood to sapwood was unusual comp ared with that of other temperature hardwood forests. Coarse woody deb ris represented significant carbon and nitrogen pools, with ca. 150 Mg .ha(-1) and 370 kg.ha(-1), respectively, in one stand. The coarse wood y debris component of these broad-leaved evergreen hardwood forests wa s much higher than that reported for other temperate hardwood forests and approaches that of many northern hemisphere conifer forests. The l arge coarse woody debris pools are discussed in relation to live stand biomass, natural disturbances and tree mortality, and decomposition p rocesses.