Interim recovery plan no. 198 Assemblages of Organic Mound (Tumulus) Springs of the Swan Coastal Plain Recovery Plan

2. RECOVERY AIM AND CRITERIA

Objective

To maintain or improve the overall condition of the tumulus springs and the associated fauna and plant community in the known locations and reduce the level of threat, with the aim of reclassifying the community from Critically Endangered to Endangered.

Criteria for success

An increase of 10% or more in the area, and/or increase in the number of occurrences of this community under conservation management.

• 
  a gain in the area of buffer vegetation under conservation management adjacent to the springs of 10% or more,
  
• 
  reduction of 10% or more in the cover of exotic plant taxa in the springs or buffer areas,
  
• 
  groundwater levels and quality maintained within the parameters expected as a consequence of natural change, by comparison with monitoring results for the Gnangara Mound in areas remote from development.
  

Criteria for failure

A decrease of 10% or more in the area covered by the springs, and/or decline in the number of occurrences of this community under conservation management.

• 
  a decline in the area of buffer vegetation under conservation management adjacent to the springs of 10% or more,
  
• 
  increase in the cover of exotic plant taxa in the springs or buffer area of more than 10%,
  
• 
  groundwater levels and quality not maintained within the parameters expected as a consequence of natural change, by comparison with monitoring results for the Gnangara Mound in areas remote from development.
  

3. RECOVERY ACTIONS

Note: The responsible authority is frequently listed as the relevant DEC District. This refers largely to initiating and guiding actions. However, in general the relevant DEC District, in cooperation with the Species and Communities Branch (SCB) and the Recovery Team has the primary responsibility for securing funds for recovery actions.

Future Recovery Actions

1. Coordinate recovery actions

The Swan Region Threatened Flora and Communities Recovery Team (SRTFCRT) will coordinate recovery actions for the Tumulus Springs and other TECs and Declared Rare Flora in their Region. They will include information on progress in their annual report to DEC’s Corporate Executive and funding bodies.

2. Map habitat critical to survival

It is a requirement of the EPBC Act that spatial data relating to habitat critical to survival be determined. Although this habitat is described in Section 1, the areas as described (other than the area of the actual occurrences, see 3.3 below) have not yet been mapped and that will be redressed under this action. If any additional occurrences are located, then habitat critical to survival will also be determined and mapped for these locations.

3.3 Clarify and continue to monitor the extent and boundaries of the community

The extent of all known occurrences have been mapped from on-ground survey and aerial photographs.

3.4 Liaise with current land owners, land managers and other interested groups to implement recommendations held in this recovery plan

Owners of land that contains the mound springs were officially informed of the presence of a TEC on their land in March 2005.

3.5 Disseminate information about the community

To seek knowledge of other occurrences, prevent accidental destruction and gain public support for its conservation, information about the community will be provided by local DEC staff to all stakeholders including landholders, and managers of land that contains the community. This would include information from the threatened ecological community database, and maps indicating the location of the community. Information about private land will only be provided to the landholder, unless permission is granted by the landholder to allow wider dissemination of the data. This action is recommended in English and Blyth (1997).

3.6 Monitor water levels and quality

The water levels and quality have been monitored since the endorsement of the previous recovery plan. Water samples were analysed from Occurrence 1, 2, and 3, as part of fauna sampling in 2002 (Pinder 2002). Additional water samples were collected and analysed from Occurrence 4 in October 2004 as part of water quality monitoring before and after a four wheel drive gymkhana was held on adjacent land. Two water samples were taken 1 week before, 1 day and 2 weeks after the event. Levels of hydrocarbon contamination were found to be insignificant in these samples. Monitoring bores have also been installed at Occurrence 3 as part of a shallow hydrogeological study of the spring (S. Burton, personal communication).

3.7 Manage water quality and quantity

Any developments or activities that would adversely impact the quality or quantity of the groundwater supply to the spring areas will ideally be avoided. This will require liaison with regard to the maintenance of water supply from the Gnangara Mound itself.

3.8 Monitor the flora and fauna of tumulus springs

Over the last few years, it has been noted that patches of ferns within Occurrence 3 were dying. The deaths were investigated but the cause could not be determined. Possible causes include water drawdown, reduced water quality, herbicide use for weed control, or the impacts of trampling. The fern deaths will be continually checked as part of the monitoring program.

9. Develop and implement Fire Management Plans that encompass actions 3.9.1 - 3.9.4

3.9.1 Develop fire management plans to ensure peat mounds do not burn, and to reduce weed invasion

There is a need for research into recovery of the community from wild fires, and to determine the implications of findings for management. For example, Occurrence 1 was burnt in a hot fire in 1995 and most of the understorey was destroyed. There has been no monitoring of flora or fauna at this occurrence since the fire. Information on the recovery of the springs would be useful for future management if fire was to occur in this or other occurrences.

3.9.2 Ensure maintenance of appropriate strategic firebreaks to help prevent fire spreading to the spring communities

Firebreaks have been established at Occurrences 1, 3 and 4. Strategic firebreaks were constructed around the tumulus springs at Occurrence 3 (~June 1996) with hire of machinery funded by DEC (subsidised by City of Swan), and volunteer labour provided by the Bullsbrook Volunteer Bushfire Brigade.

3.9.3 Liaise with surrounding landholders to ensure strategies for fuel reduction on their lands do not impact the community

In particular, there should be no earthworks to construct firebreaks on degraded mounds to the north of the spring areas in reserve 46622 or adjacent to Occurrence 3 and 4 as such works may sever conduits supplying water to the springs; and controlled burns that may become wildfires in drier conditions and result in the peat mounds being burnt, should be avoided.

3.9.4 Ensure fire suppression strategy does not impact community

DEC is responsible for fire management on land managed by DEC outside the metropolitan gazetted fire district, while Fire and Emergency Services Authority (FESA) is responsible for managing fires in gazetted areas and non-DEC-land.

3.10 Ensure earthworks near the springs do not impact the community

DEC staff will liaise with relevant landholders to ensure earthworks near the springs and on adjacent lands that may impact the hydrology are avoided. For example, levelling or performing earthworks on adjacent lands, in particular on the denuded mounds to the north of springs on reserve 46622 and north of Occurrence 3 may impact the flow to the mounds.

3.11 Design and conduct research

Considerable research has been conducted on the hydrology of the Gnangara Mound by the Water Corporation and Water and Rivers Commission (now Department of Water). Such work indicates that the continuing fall in water levels in the Gnangara Mound are a result of interaction between declining rainfall, large pine plantations and water abstraction for public supply and commercial horticulture.

2. Investigating the implications of falling water tables of the Gnangara Mound on the hydrology of the mound spring occurrences.

3. Investigating the palaeobiology of tumulus springs through peat studies.

4. Investigation of significant biological processes in the community such as faunal interactions.

5. The potential impacts of water pollution such as pesticides, herbicides and fertilisers on the spring biota.

6. Taxonomic research on invertebrate fauna of the springs.

12. Ensure hygiene conditions near the community

Risk of introduction or amplification of disease is being minimised by ensuring good hygiene procedures. This involves washdown of any equipment used adjacent to the community, and restricting access by vehicles, machinery and personnel to dry soil conditions.

3.13 Continue to monitor dieback

Dieback was monitored at Occurrences 1, 3, and 4 in June 2004. Dunes adjacent to Occurrences 1, 2 and 3 are vegetated with Banksia woodlands that are commonly very susceptible to dieback caused by Phytophthora species. The dune adjacent to Occurrence 1 appears to have been historically denuded, in part at least, by dieback infection.

3.14 Monitor and implement weed control

Weed control has primarily been focused at Neaves Road (Occurrence 3). The control of invasive weeds of Rubus sp. (blackberry) began in 2001 and has continued as required, with the last weed treatment occurring in April 2004. Weed control at all occurrences will be continued annually.

3.15 Rehabilitate recharge catchment zones and adjacent wetland areas

The dune to the west of the tumulus springs in reserve 46622 will be revegetated with local species that may aid water infiltration and recharge. Heath species, rather than trees would use less water and will be used for rehabilitation of this dune. In addition, revegetating or maintaining healthy vegetation on the dunes adjacent and to the west at each site may help sustain the current hydrological regime of the local recharge zones.

3.16 Report on success of management strategies for tumulus springs

The success of management strategies will be assessed as part of annual reports prepared by the Recovery Team for DEC’s Corporate Executive. The final report will be evaluated as part of the revision of the recovery plan for this community.

3.17 Support reservation of Occurrence 2 and adequate buffer area

Negotiations will be continued to seek reservation of the springs in Occurrence 2, and an adequate buffer of remnant vegetation around the springs. The mound springs and a small buffer are to be vested with WAPC and later managed by DEC. Further negotiations will be required for declaration of the area as Class A reserve for the purpose of ‘Conservation of Flora and Fauna’ under the care, control and management of the Conservation Commission.

3.18 Fence Occurrence 2

DEC staff will liaise with the landowner to determine the appropriate location for fences to protect the occurrence and a suitable remnant vegetation buffer area.

3.19 Ensure visitor access-ways do not impact the tumulus springs

Any visitor access-ways including walk/cycle paths and boardwalks will be designed such that they do not impact hydrology around tumulus springs and such that direct disturbance to the springs is minimised.

3.20 Block drain on south east corner of Neaves Road Nature Reserve

A drain links the springs to adjacent partly cleared land on the eastern edge of the reserve and nutrient enriched water from the adjacent paddock may be able to flow into the springs from this paddock. This drain will be blocked and revegetated.