Appendix 2 - Vegetation Communities and Regional Ecosystems

8.0 Ecosystem Condition
The notion of the ‘naturalness’ or ‘integrity’ of the Torres Strait Island region can be attributed to
factors such its isolation in combination with underlying climatic conditions, geomorphic history
and edaphic controls, but must also acknowledge the influences on the landscape associated with
long-term human occupation. The concept of ‘constructed landscapes’ whereby Indigenous
Australian’s intentionally manipulated their environment through a number of processes is
explored in the Torres Strait Islands by McNiven (2008), on Saibai Island by Barham (1999), on
Moa and Badu Islands by Rowe (2006), and on coastal north-east Cape York Peninsula by Hynes
and Chase (1982). It is not the intention to elaborate on these findings other than to identify the
occurrence of the more readily recognisable aspects of disturbance as they affect or appear to
affect ecosystem condition and distribution as observed during this study, and to offer brief
descriptive comment. Additional work, which combines the ecological, geomorphological,
archaeological and anthropological disciplines, is required to compliment the existing body of
knowledge in this field, and the preliminary discussions provided here.
The more obvious anthropogenically altered landscapes have been identified in Section 5.4 and
include bamboo groves, which are prominent on the eastern basaltic islands of Mer, Erub and
Ugar where they commonly form mosaic with vine forest and vine thicket communities, and have
been identified in the mapping as such. Bamboo groves also occur on the continental islands of
Moa, Iama, Mabiaug and Gebar. The mapping also identifies the extent of vegetation which is
dominated by exotic or naturalised species other than bamboo, and recognises extensive areas of
tall closed forest of Mangifera indica (Mango) or Delonix regia (Poinciana), and former
grassland areas more recently invaded by Lantana camara (Lantana). Again, the occurrence of
these types is most prominent on Mer and Erub where distinctive regrowth formations under tall
and senescing Cocos nucifera (Coconut) groves, thought to be old garden sites, were also
observed and are discussed in Section 5.2.57.
McNiven (2008) identifies species such as yams (Dioscorea spp.), taro (Colocasia esculenta),
bananas (Musa spp.), sugarcane (Saccharum spp.) and sweet potatoes (Ipomoea spp.) as ‘plant
inclusions’ defined as “the strategic addition or translocation of certain ‘exotic’ plants and
animals to areas”. In contrast to these species, which are often associated with gardens and
margins of heavily disturbed areas, are species such as Poinciana, Mango and Coconut which, by
way of their dispersal and adaptive qualities, occur in sufficient quantities to form distinct and
mappable vegetation communities. Low shrubland and vine thicket on Masig Island mapped in
VC22b, is recognised from analysis of aerial photography in combination with field survey and
local input as advanced regeneration of former traditional gardens.
Regrowth vegetation, the result of past clearing or partial clearing of natural vegetation, in
varying stages of recovery, is recognised on the majority of island groups that have been subject
to human occupation and are represented in the mapping as the Unit ‘Re’. The derivation of
regrowth examples observed on Erub, where Barringtonia calyptrata groves occur on the
margins of remnant vine forest vegetation, are unclear, however regenerating mangrove
shrublands on Boigu and Iama are the result of recent mechanical actions. On Boigu Island,
mangrove shrublands shown in Photographs 187 and 188 are a result of land reclamation
initiatives. Contemporary evidence of vegetation clearance (vine forest/thicket on beach ridges)
for traditional gardens is noted Boigu Island in RE 3.2.2b (see photograph 189). Examples of
larger scale remnant vegetation clearing on Masig Island (in RE 3.2.6) are associated with recent
major infrastructure developments. Prehistoric gardens on Saibai described by Barham (1999)
are recognised within a discrete mapping unit (VC1e) as distinct from the extensive and
widespread Pandanus associated grassland communities (VC11a).
3d Environmental – Torres Strait Regional Ecosystem Mapping Project – August 2008
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