Phytophthora cinnamomi -status of quarries Q to the DPEMP.pdfCommercial-in-confidence Nook Quarry...
Transcript of Phytophthora cinnamomi -status of quarries Q to the DPEMP.pdfCommercial-in-confidence Nook Quarry...
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Commercial-in-confidence
Nook Quarry – AG & BJ Riley
Phytophthora cinnamomi-status of quarries
Quarry: Nook Quarry Date of inspection: 27/08/08
Altitude: 335 m Reinspection due: On request
Substrate: Conglomerate Type: Consolidated and unconsolidated
gravel deposits
Grid Ref: 445238 E, 5425713 N Owner: AG & BJ Riley
Drainage: Excellent
The quarry floor is clean and dry (Figure 1). Good outfall drainage is provided, with
sumps in place (Figure 2). A spoon drain in place at the top of the quarry (Figure 3)
prevents water runoff from entering the active quarry area.
Overburden:
The older areas of the quarry have been well scalped back from the quarry face. A newer
area of the quarry, which has been recently blown, did not have the overburden scalped
back and the quarry area has suffered slight contamination with topsoil (Figure 4).
Field symptoms: None seen
This quarry is supporting a wide variety of reliable indicator species including: common
heath (Epacris impressa), bearded heath (Leucopogon virgatus), Banksia marginata,
goldey wood (Monotoca glauca), trigger plant (Stylidium graminifolium), golden pea
(Aotus ericoides) and Amperea xiphoclada (Figures 5 & 6). All appeared healthy and
were regenerating well on disturbed areas (Figures 7 – 9), indicating an absence of
P. cinnamomi. Common heath is regenerating at the outflow of the lowest sump. This
indicates that the water flow from the quarry is free of P. cinnamomi (Figure 10).
Samples tested for P. cinnamomi: Nil – Not required as no field symptoms were
observed.
This quarry is currently considered to be P. cinnamomi-free
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Commercial-in-confidence
Nook Quarry – AG & BJ Riley
Management issues/recommendations:
This is currently a well-managed, P. cinnamomi-free quarry, which is a valuable asset.
The following recommendations will help to ensure that the quarry stays clean into the
future:
• P. cinnamomi is easily carried by water or in mud. Ensure the quarry floor remainswell drained and no water ponding occurs in working areas.
• Ensure any trucks coming into the quarry are clean and do not drop mud intoworking areas. Request a wash-down procedure if trucks are working in a muddy
area.
• P. cinnamomi can not survive in clean dry gravel, but can spread where soil and rootmatter are incorporated. The topsoil should be scalped back from the active quarry
face.
• Where rehabilitation is required, spreading a thin layer of topsoil carrying the seedsof native species will speed up the regeneration process, but in all other cases topsoil
should be well separated from the working area and the quarried material and
preferably stored down-hill from the active area.
• Do not allow imported topsoil to be dumped within the quarry. This is one of thequickest ways of contaminating a clean quarry with both disease and weed problems.
Treat any weed problems promptly, should they arise.
Figure 1. The quarry floor is hard, dry and uncontaminated by any other material
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Commercial-in-confidence
Nook Quarry – AG & BJ Riley
Figure 2. Good outfall drainage is
provided and is working effectivelyFigure 3. A spoon-drain at the top of the
quarry prevents water flow into the quarry
Figure 4. Contamination
of the quarry area with
topsoil can largely be
prevented by scalping
back the overburden.
Clean gravel does not
support P. cinnamomi.
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Commercial-in-confidence
Nook Quarry – AG & BJ Riley
^ Figure 5. This quarry supportsgood indicator species such as
bearded heath and Amperea.
Figure 6. Healthy regeneration of
these species indicates an absence
of P. cinnamomi. >
Figure 7. Good regeneration of indicator species is
establishing on the scalped slope. Many native species
have ground-stored seed and will regenerate after severe
disturbance.
Figures 8 & 9. Golden
pea, bearded heath and
trigger plant (all reliable
indicator species) are
regenerating in the gravel.
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Commercial-in-confidence
Nook Quarry – AG & BJ Riley
Figure 10. Common heath
thriving at the outfall of the
lowest sump indicates that
the all of the area above is
clear of P. cinnamomi.
Sue Jennings
Biology & Conservation Branch
Forestry Tasmania