Flood Plain Lower Ringarooma River Ramsar site Ecological Character Description March 2012 Blank page Citation

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1.7Critical Components and Processes and Essential Elements

1.7.1Critical components and processes

The production of an ECD requires the identification, description and where possible, quantification of the critical components and processes that characterise the site. As a minimum, DEWHA (2008) recommends the selection of critical components and processes as those:

that are important determinants of the site’s unique character;
that are important for supporting the Ramsar criteria under which the site was listed;
for which change is reasonably likely to occur over short to medium time scales (<100 years); and
that will cause significant negative consequences if change occurs.

Identification of the critical components and processes also lead to identification of components and processes that may not be critical to the site, but are important in supporting the critical components, processes, benefits and services. These have been termed ‘essential elements’ by DEWHA and may act as early warning indicators of a potential change in character and therefore should be considered in management planning for the site (Hale 2010). Using the approach of Hale (2010), a simple conceptual model has been developed that displays the essential elements for the site, the critical components and processes and benefits and services and the listing criteria (Figure 17). The model also shows the links between these features.

Nine critical components and processes were identified for the site. These are summarised as follows:

wetland types (the eleven identified Ramsar wetland types)
regionally rare plant species (the four State-listed species)
internationally rare bird species (the fairy tern)
regionally rare bird species (white-bellied sea eagle and little tern)
nationally rare fish species (including the dwarf galaxias and Australian grayling)
green and gold frog
nesting shorebirds (including the fairy tern)
listed migratory birds (the eleven JAMBA/CAMBA/ROKAMBA/CMS species)
migrating fish, including the Australian grayling, Tasmanian mudfish and Tasmanian whitebait.

All of these meet the four criteria provided by DEWHA (2008): they are central to the unique character of the site; they are directly linked to the Ramsar criteria for which the site was listed; they could potentially change in the next 100 years; and their change would result in a negative change in the ecological character of the site. Each of these has been described within the sections above (3.1 and 3.2).

In this ECD, geomorphic components and processes are split into ‘coastal’ and ‘fluvial’ geomorphology. The distinction in this report is to separate the coastal processes that form the sandy beaches and dunes, from the effects of the river water flows on the wetland landforms.

Figure 17: Conceptual model of the components, processes and services of the site, and their links to the Ramsar criteria.

1.7.2Essential elements

The identified essential elements for the site are:

climate
geomorphology
hydrology
water quality
terrestrial vegetation
fish and invertebrates (as food for fish and birds)

Each of these provide essential support to the critical components and processes of the site, but are not part of the site’s unique character. Significant changes to any of the essential element will be reflected in one or more of the critical components and processes.

1.8Critical benefits and services

The critical services supporting the ecosystems of the site can be identified using the same determinants (Section 3.4.1) as those used for selecting the critical components and processes (DEWHA 2008).

None of the benefits displayed in Table 9 were considered critical to the site’s ecological character. Although they may be beneficial to humans, they do not support the listing criteria nor would a change to any of them be likely to have significant consequences to the site’s ecological character. In contrast, each of the ecosystem services presented in Table 10 are critical to the site’s ecological character.

Each of the critical benefits and services of the site is represented through critical components and processes as displayed in Table 11.

Table 11: Summary of critical ecosystem services and their associated critical components and processes.

General ecosystem service	Specific ecosystem service	Associated critical component/process
Maintenance of rare and representative wetland types for the bioregion (criterion one).	Supports Ramsar wetland types.	The eleven Ramsar wetland types.
Support for rare or threatened species (criterion two).	Support nationally rare bird species.	Fairy tern
	Supports nationally rare fish species.	Australian grayling and dwarf galaxias
	Supports green and gold frog.	green and gold frog
Supports populations important for regional biodiversity and/or at critical stages (criteria three and four).	Supports regionally rare bird species.	little tern, white-bellied sea eagle
	Supports regionally rare plant species.	The four wetland dependent State listed species.
	Supports migratory bird species.	The eleven listed migratory bird species.
	Supports nesting shorebird species.	little tern, hooded plover, fairy tern, pied oystercatcher and red capped plover.
	Supports migrating fish species.	Tasmanian mudfish, Tasmanian whitebait, Australian grayling.

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