Distribution, abundance and biomass of epiphyte-lianoid communities in a New Zealand lowland Nothofagus-podocarp temperate rain forest: tropical comparisons
In tropical rain forests, epiphytes can contribute significantly to species diversity and biomass, a feature not generally associated with temperate forest systems. This study investigates epiphyte-liane diversity and biomass on three host trees (two Dacrycarpus dacrydioides [Podocarpaceae] and one Nothofagus menziesii [Fagaceae]).Location
These trees were of varying architecture on different sites in a New Zealand lowland temperate rain forest at 45°43′ S.Methods
Cover of epiphytic and lianoid species (vascular and non-vascular) was recorded in 5 m vertical height segments (trunk), on four aspects (north, south, east and west); and in four sections (inner, middle, outer branches and branch extremes) on four branch faces (positions: topside, both sides, underside) on each tree. Inclination, branch face, and diameter of branch/trunk substrate, height above ground, duff thickness, and location on tree (trunkfoot, main trunk, inner branches, middle branches, outer branches, branch extremes) were all recorded in 359 samples. Epiphytic biomass was derived for one tree.Results
Sixty-one vascular and ninety-four non-vascular taxa were recorded. Eight communities associated with the highly vegetated inner branches and main trunk, and seven indicative of the less vegetated middle to outer branches and branch extremes were recognized. Thirteen of the fifteen communities were present on a forest interior D. dacrydioides tree, nine on a riverside D. dacrydioides tree and seven on a N. menziesii tree. Most of the seven measured environmental variables were statistically significant in relation to ordination analyses of the samples. Dry mass per unit area and dry bulk density recorded were 350 ± 125 and 118 ± 13 g dm–2, respectively (trunkbase), and 206 ± 21 and 91 ± 4 g dm–2, respectively (inner and middle branches combined).Main conclusions
Epiphytic community analyses that do not include non-vascular flora either as generalized categories or as individual taxa are incomplete. Values for epiphytic dry weight for the trunkfoot of one tree appear to exceed comparable figures recorded from tropical rain forest systems. Epiphytic communities and biomass within at least some temperate rain forests can be validly compared with those of tropical rain forests.