Other trees and shrubs

Long description

Intertidal vegetation other than mangroves, on Quaternary estuarine deposits but infrequently inundated. These communities occur at the tidal interface and are typically dominated by Casuarina glauca or Melaleuca spp., noting that C. glauca does not extend north of Bioregion 12 (i.e. northern extent of range).

Typically occurs in high groundwater expression areas or at the upstream end of estuaries. There is often an interplay between the tidal flow and freshwater head with two basin types:

• those trees with roots in contact with saline groundwater (C. glauca)
• tidally inundated with freshwater being moved by the tide (Melaleuca spp.).

Special values

Environment Protection and Biodiversity Conservation Act (1999)-listed ecosystem.

Diagnostic attributes

Inundation 'Intertidal – Lower low', 'Intertidal – Mid low', 'Intertidal – Upper low', 'Intertidal – Low undifferentiated', 'Intertidal – Lower medium', 'Intertidal – Upper-medium', 'Intertidal – Medium undifferentiated', 'Intertidal – High', 'Intertidal – Undifferentiated', 'Intertidal – High undifferentiated', although they occur closer to the higher tidal planes which remain unmapped.

Structural macrobiota 'Other trees and shrubs'

Qualifiers

The naturalness qualifier is relevant as tidal inundation may sometimes be modified by infilling and reclamation, barriers, and excavated channels (modifying inundation and terrain morphology). Changes in tidal inundation will be reflected by changes in structural macrobiota.

No qualifiers mapped however Period and Trend are relevant as mangroves and adjacent ecosystems can be influenced by sea level rise.

Clearing of vegetation will change the composition of Structural macrobiota (e.g. height, percentage cover, biomass) and these communities would be mapped as type (119).

Distribution

Melaleuca spp. also occur in areas of indeterminate inundation (type 119) where they are mapped by freshwater wetlands mapping for the state.

The following relates to distribution of this ecosystem type within the Central Queensland mapping area:

• Large area in the Central Queensland mapping area between Baffle and Littabella creeks, which is below highest astronomical tide but dominated by freshwater.
• In bioregion 11, Melaleuca spp. and/or Eucalyptus tereticornis open woodland to woodland. Mangrove trees and shrubs are often present, and there are sometimes scattered shrubs of Myoporum acuminatum. There is usually a dense ground layer of Sporobolus virginicus, together with other species such as Vincetoxicum carnosum, Fimbristylis ferruginea, Cyperus scariosus, Cyperus polystachyos, Gymnanthera oblonga, Acrostichum speciosum and Centella asiatica. Occurs on transition zone between tidally inundated areas and areas under freshwater influence. May include 11.1.3a (Melaleuca spp. and/or Eucalyptus tereticornis open woodland to woodland), 12.1.1 (Casuarina glauca woodland on margins of marine clay plains)[1].
• In Bioregion 12, mostly Casuarina glauca open forest to low open woodland. Occurs on margins of Quaternary estuarine deposits. May include 12.2.7 (Melaleuca quinquenervia or rarely M. dealbata open forest on sand plains), 12.2.12 (Closed heath on seasonally waterlogged sand plains)[1].

Comments

Other relevant attributes include Consolidation, Energy and Sediment texture as these ecosystems typically occur on unconsolidated muds and fine sediments in low energy environments.

Freshwater source and volume are relevant as the mix of species may change in areas subject to groundwater and/or freshwater influence.

References

1. ^ a b Queensland Herbarium & Environmental Protection Agency, B (2005), Regional Ecosystem Description Database (REDD). Version 5.0. [online], Environmental Protection Agency, Brisbane. Available at: https://apps.des.qld.gov.au/regional-ecosystems/.

Last updated: 19 July 2019