Appendix 2 - Vegetation Communities and Regional Ecosystems

5.2.64 Regional Ecosystem 3.12.16
Description: Melaleuca viridiflora, Asteromyrtus brassii woodland. Associated with granitic
hills.
Status: Not of Concern
Vegetation Communities: 14k, 13i, 14x, 14w (co)
Reference Sites: 2 Secondary (ZS14, PWS11), 2 Quaternary (PWQ10, HAQ17a)
Small areas of this RE are scattered throughout the inner island group, with minor areas also
mapped on Moa Island and some extensive areas also represented on Muralug. The low
shrubland (VC14k) blankets a broad topographic depression in the central portion of Zuna Island
with VC13i much less extensive. The RE is typically manifest as a shrubland and rarely low
woodland with Melaleuca stenostachya forming a prominent component of the canopy species.
Structurally and floristic similarities are shared with coastal headland shrublands (refer to
RE3.12.31x1a) although differentiation is based largely on ecological controls. Whilst extreme
exposure is the limiting factor in development of shrublands on exposed coastal headlands, the
development of RE3.12.16 is limited largely by soil infertility and moisture. Both VC14k and
VC13i are assigned to RE sub-type 3.12.16c whilst VC14x, represents the RE sub-type 3.12.16d.
Vegetation community 14x occupies an extensive portion the rocky central interior of Muralug
Island as component of the complex VC14w.
Vegetation Community 14k: Vegetation community 14k is resticted to a broad topographic
depression in the central portion of Zuna Island, occupying an area of skeletal soil formed on hard
white acid volcanic rocks (rhyolite). The infertility of this substrate is the dominant control on
shrubland development. Melalueca stenostachya forms the dominant component of the
shrubland which has a general canopy height of 1.5 to 2m with sub-dominant to co-dominant
species including Melaleuca viridiflora, Asteromyrtus symphyocarpa, Asteromyrtus brassii and
Jacksonia thesioides. The canopy is relatively even although is frequently broken with areas of
unvegetated acid volcanic rubble.
Photograph 136. Shrubland type
14k in a broad topographic
depression on Zuna Island.
Vegetation Community 13i: Vegetation community 13i represents near pure stands of
Melaleuca stenostachya, growing in shrubland or low woodland formation on acid volcanic
rocks. The type is represented in only a few locations on Moa, Muralug and Hammond Islands
with small areas forming on low rises in the acid volcanic basement, or on colluvial slopes where
a thin thin blanket of poorly drained silty soils is retained. Typical of the occurrence of M.
stenostachya in other communities, the species indicates extremely infertile edaphic condition.
3d Environmental – Torres Strait Regional Ecosystem Mapping Project – August 2008
136