Appendix 2 - Vegetation Communities and Regional Ecosystems

5.2.74 Regional Ecosystem 3.12.35 (New RE)
Preliminary Description: Semi-deciduous mesophyll/notophyll vine forest on granite slopes of
the Torres Strait Sub-region.
Status: Of Concern
Vegetation Communities: 2d, 2h, 2o, 2q, 2r, 2t, 6a, 6e
Reference Sites: 8 Secondary (YAO4, YA05, MO003, PW085, PW093, HA05, YA18, YA21)
To provide an adequate ecological grouping for the deciduous and semi deciduous vine forest
communities in the Torres Strait, it is necessary to erect an additional RE to accommodate a
diverse array of vine forest types that characterise the steep granitic and acid volcanic slopes of
many of the continental islands. These forests extend from the Northern Island Group, being
particularly abundant on Dauan, through the central group on Iama and Gebar, the Near Western
Group and the Inner Island Group. Vine forest communities often vary subtly between islands
and as such, minor floristic or structural variations can be represented with relative confidence
due to the ecological isolation imposed by island boundaries. The constituent vegetation
communities of newly described RE3.12.35 are described below.
Vegetation Community 2d: VC 2d is mapped on the steep, boulder strewn mid to upper slopes
of Dauan Island, demonstrating a marked structural contrast to the thickets of the lower slopes.
Canopy heights in this community range from 18 to 25m and constituent species are both
deciduous and semi-deciduous consistent with its structural classification as a semi-deciduous
vine forest. Dominant canopy species include Tetrameles nudiflora, Alstonia spectabilis,
Ganophyllum falcatum, Bombax ceiba var. leiocarpum, Canarium australianum, Ficus virens
var. sublanceolata, Ficus microcarpa and *Mangifera indica. Sub-canopy species were not
sampled in detail although Gossia floribunda was abundant in some locations, and hemiepiphytes
including Asplenium nidus, Drynaria quercifolia and Microsorum punctatum are
prominent. The community is notable for the diversity of epiphytic plants including Dendrobium
litorale, Bulbophyllum spp., and Dischidia littoralis, listed as Vulnerable (NCA, 1992), which
was particularly abundant. With reference to Herbrecs data and Stanton and Fell (2005), the
occurrence of Tetrameles nudiflora represents a considerable extension of geographical range
north from Schram Creek, although Hyland et al. (2003) record it from northern Torres Strait. Its
presence on Dauan on steep granitic boulder slopes is considered unusual, as it is more
commonly associated with seasonally flooded lowland alluvial terraces e.g. Claudie River
(RE3.3.1). This species also occurs throughout lowland PNG (Conn et al. 2006+).
Photograph 163. In foreground, the
deciduous crowns of Tetrameles
nudiflora in flower are clearly visible
in the canopy of VC2d.
3d Environmental – Torres Strait Regional Ecosystem Mapping Project – August 2008
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