Appendix 2 - Vegetation Communities and Regional Ecosystems

5.2.43 Regional Ecosystem 3.3.62
Photograph 94. Grasslands on a
broad alluvial plain on Gebar Island.
The community in this location
represents a fire climax community
with vine forest (the original
vegetation type) clearly visible in the
background.
Description: Grassland/sedgeland with Pandanus spp. Confined to Torres Strait Islands.
Status: Of Concern
Vegetation Communities: 17a, 17e, 11a
Reference Sites: 3secondary (SA15, SA21, BO16), 33 Quaternary
This RE comprises a mosaic of grassland, shrubland and low woodland types, confined mostly to
Northern Islands group with extensive areas on Saibai Island. More restricted and scattered areas
occur on Boigu, and isolated examples are also represented on Hammond and Moa Islands (Inner
and Near Western Island Groups respectively). The RE is endemic to the Torres Strait.
Vegetation Community 17a: The dominant component of this ecosystem is VC17a, generally
developed as a closed tussock grassland dominated by Ischaemum australe with associated
species Imperata cylindrica, Themeda triandra, Mnesithea rottboellioides, Vandasia retusa, and
Derris trifoliata. Species associated with brackish margins include Fimbristylis ferruginea,
Acrostichum aureum, and Cynanchum carnosum. Characteristic emergent shrubs are Acacia
leptocarpa, Melaleuca cajuputi subsp. platyphylla, Pandanus sp. Livistona muelleri, Antidesma
parviflorum, Acacia auriculiformis and less commonly Dillenia alata on the Northern Island
Group. This VC is represented in Photograph 95.
Vegetation Community 17e: Vegetation Community 17e represents anthropogenically
disturbed areas on Saibai Island which have re-established native grass cover. These
communities are clearly identifiable on aerial photography due to their intricate and precisely
constructed furrow and ridge morphology, indicative of prior cultivation. Barham (1999)
identifies this feature as former prehistoric tropical field systems with characteristic physical
traces of relict agricultural mounds and ditches. Barham and Harris (1985), in Barham (1999)
report that the field systems on Saibai were partly in use as late as 1945 with detailed mapping
carried out as part of archeological investigations indicating previous use of some 650 ha of land
area. High cultural values are therefore assciated with this vegetation. This community is
composed of grass species typical of VC17a, although they lack the prominent emergent shrub
layer. A representative community is illustrated in Photograph 96.
3d Environmental – Torres Strait Regional Ecosystem Mapping Project – August 2008
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