Information

Level 2: Details of Experimental Conditions and Methods

When and Where

The study was carried out in the Burdekin River Catchment, a major catchment of the Great Barrier Reef (approx 130,000 km2) west of Townsville. The study of this site was conducted on June 2000 and July 2001.

Site description:

  • MLA erosion monitoring site (micro plots, hillslope runoff plots and stream gauging);
  • History of heavy stocking but with a grazing enclosure;
  • General site condition poor to very poor (with exception of enclosure with excellent condition).

Soil Type

The soils from the sites are varied but generally old and weathered with a large proportion of duplex soils. With the exception of soil derived from basalt (Vertosols or Ferrosols) most of the soils are low in fertility and due to their textual properties, are particularly prone to crusting. The six sites are located on duplex or gradational soil types that are common within the Upper Burdekin River Catchment.

Soil Description for Meadowvale (Site 5):

  • Red  Chromosols (Dalrymple Series, eroded phase);
  • Sand 48-79%
  • Clay 11-41%
  • Bulk Density 1.43-1.61g/cm3;
  • OM content 0.7-1.8% C;
  • Moisture 0.11-0.1 % volume;
  • Ground Cover 1-96%; and
  • Biological Activity 1-4

Landscape Features

Feature of Meadowvale include:

  • P Narrow leaf Ironbank and Bloodwood are the dominant tree species;
  • Indian Coach is the dominant grass and legume species;
  • Hillslope position and angle Upper to Mid slope 5 to 8%; and
  • Granodiorite (Geology).

How

Six sites were selected on duplex and gradational soil types typical of large parts of the catchment. Individual plots reflecting the main classes identified were selected with 2 to 4 replicates per class, resulting in about ten to sixteen plots per site.

The rainfall simulator consisted of 1m2 capillary tube (inner diameter 0.5mm) drop forming chamber mounted on a 4m high aluminium tower. The tower is attached to a trailer that supports the equipment to conduct the rainfall simulation.

The rainfall intensity varied between 30 and 75 mm h-1. The targeted intensity for this study was 60 mm h-1 for 30 mins, which represents a storm event having a 1 year return period for northern Queensland.

Metal runoff plot frames 0.4 m by 0.6 m in size were placed in the middle of the rainfall plot, thus allowing a 0.2 to 0.3 m buffer zone around the plots. An angle grinder was used to cut slots into dry ground to enable insertion of the frame into the soil without disturbing surface features.

The soil features recorded from the experiment include the following:

  • Estimate of ground cover (green material and litter);
  • An assessment of microreleif and plot slope; and
  • Range of macroscopically visible crust.

In addition the following criteria were recorded as proposed by (Tongway and Hindley, 1995), this includes:

  • Presence and type of crust;
  • Extent of cryptogams;
  • Extent and nature of surface lag and gravel cover;
  • Presence of pedestals;
  • Degree of litter incorporation;
  • Presence of macropores; and
  • Extent of surface casting.

Soil cores were taken from within each plot after the event for bulk density measurements at depth of 1 cm to 5 cm. Soil moisture was measured to a depth of 1 cm to 5cm for each plot.

Site identifier code: N/A

Principal investigator: Roth CH

Principal data manager: N/A

Principal organizations: CSIRO

Data custodian: CSIRO

Key co-operators: N/A

Data access policy: Research has been published but base data is not archived

Planned pathway for data: completed study, no evidence of formal database records.

Data warehousing: for ongoing studies N/A

Planned data upload frequency: for ongoing studies N/A

 

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