Distribution and abundance of coarse woody debris in some southern New Zealand streams from contrasting forest catchments

The volume, biomass, and carbon and nitrogen content of coarse woody debris were measured on three 1-ha reference plots in old-growth Nothofagusfusca (Hook. f.) Oerst.–Nothofagusmenziesii (Hook. f.) Oerst. forest on the South Island of New Zealand. Two decay sequences for logs and one for standing dead trees (snags) were recognised from two-way indicator species analysis (TWINSPAN) of up to 30 variables related to physical characteristics and structural integrity. Wood volume (up to 800 m3•ha−1) and biomass were high (up to 300 Mg•ha−1), and the inside-out decay sequence from heartwood to sapwood was unusual compared with that of other temperate hardwood forests. Coarse woody debris represented significant carbon and nitrogen pools, with ca. 150 Mg•ha−1 and 370 kg•ha−1, respectively, in one stand. The coarse woody debris component of these broad-leaved evergreen hardwood forests was much higher than that reported for other temperate hardwood forests and approaches that of many northern hemisphere conifer forests. The large coarse woody debris pools are discussed in relation to live stand biomass, natural disturbances and tree mortality, and decomposition processes.

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Basidiomycete decay fungi within stems of Nothofagus windfalls in a Southern Hemisphere beech forest

Canadian Journal of Forest Research ◽

10.1139/x08-041 ◽

2008 ◽

Vol 38 (7) ◽

pp. 1897-1910 ◽

Cited By ~ 7

Author(s):

I. A. Hood ◽

P. N. Beets ◽

J. F. Gardner ◽

M. O. Kimberley ◽

M. W.P. Power ◽

...

Keyword(s):

New Zealand ◽

Southern Hemisphere ◽

Tree Species ◽

Coarse Woody Debris ◽

Woody Debris ◽

Beech Forest ◽

Study Data ◽

Decay Fungi ◽

Mean Diameter

Fungi were isolated to determine the predominant decomposer species active in the coarse woody debris in a beech forest in the central North Island of New Zealand. Basidiomycetes were obtained in 55% of 4569 isolation attempts from discs cut from six trees each of Nothofagus fusca (Hook. F.) Oerst. and Nothofagus menziesii (Hook. F.) Oerst. uprooted during a storm 24 years earlier. Percentage yields varied significantly among trees but not between tree species. However, for N. fusca, basidiomycetes were obtained less frequently from stems of greater mean diameter. In total, 96% of basidiomycete isolates were composed of 18 species, the most abundant being Armillaria novae-zelandiae (G. Stev.) Herink, mainly present in the outer 12 cm, and Ganoderma cf. applanatum sensu Wakef. and Cyclomyces tabacinus (Mont.) Pat., which penetrated more deeply. These fungi were distributed along the stems as somatically incompatible colonies reaching lengths of 11, 2, and 3 m for each species, respectively; those of G. cf. applanatum were separated by brown pseudosclerotial plates. Fruiting of these species was significantly associated with isolation of cultures and, for G. cf. applanatum and C. tabacinus, provided a reliable guide to stem colonization. Basidiomycete diversity in the Nothofagus stems was greater than in two podocarp species in an earlier study. Data from this investigation are being used to assess how decay fungi, together with other factors, influence rates of decomposition of indigenous coarse woody debris.

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