Sample Types in EcoPlots

TERN Australia Soil and Herbarium Collection

Overview

TERN plant and soil samples originate from the TERN Surveillance Monitoring Observatory with around 1,000 monitoring sites nationwide and are still counting. These samples form the TERN Australia Soil and Herbarium Collection at the University of Adelaide's Waite Campus. The collection is temporal and linked to extensive data, including vegetation community, plant species, and soil characteristics. This expanding library of field samples is accessible to researchers, providing valuable resources for diverse studies.

The samples represent a single point in time. Please request only the recommended quantities for specific analyses.

Plant voucher specimens

Plant voucher specimens representing all vascular plant species are collected at each plot (see diagram below) for species identification and verification. Specimens are stored in a plant press, dried after field collection, and sent to the appropriate State herbarium for species determination. Upon return to TERN, specimens are frozen for seven days, then stored in the TERN Australia Soil and Herbarium Collection’s cool room at 17^oC. Each specimen is stored one per sheet and bundled by plot location. An image library project is creating a digital archive of these specimens.

Plant tissue samples

Plant tissue samples are taken from each plant voucher specimen collected in the plot, termed the primary voucher. For the plot's four dominant species, additional tissue samples from four individual plants are collected for population genetics, termed secondary vouchers (1, 2, 3, 4; see diagram below). Tissue samples support genetic, molecular, and isotopic analyses. In the field, each sample is placed in a synthetic tea filter bag and stored in a sealed plastic container with silica gel. Long-term storage occurs in the TERN Australia Soil and Herbarium Collection’s cool room at 17^oC. Silica gel is monitored and replaced as needed.

Soil pit samples

Soil pit samples are collected at intervals down the soil profile (~1m), within horizons at one location in the SW corner at a plot (see diagram below). Additional supporting data is gathered at the pit and in the TERN lab, including soil classification, bulk density, pH and electrical conductivity (EC). Soil pit samples can be used for physical and chemical analyses. Before storage, samples are oven dried at 40^oC for approximately 48 hours, sieved, ground and then stored in sealed containers. Samples are organised by plot location and stored under ambient temperature conditions in the TERN Australia Soil and Herbarium Collection. For each horizon recognised down the soil profile, a sample from each horizon is collection (~500g per horizon).

Generally, the quantities allowable for loan are selectable from the following categories (0-10g, 10-20g, 20-60g, 60g-100g). The quantity required for loan will be dependant on the type of analyses required.

Soil subsite samples

Soil subsite samples are collected from 9 subsites within each plot (see diagram below), with pits dug to a depth of 30 cm and samples collected at 10 cm intervals. A bulk sample is also created by combining the 10 cm interval samples from all 9 subsites. Subsite samples can be used for physical and chemical analyses. Before storage, samples are oven dried at 40^oC for approximately 48 hours, sieved, ground and then stored in sealed containers. Samples are organised by plot location and stored at ambient temperature conditions in the TERN Australia Soil and Herbarium Collection. For the three 10cm intervals at the 9 subsites, ~500g of soil is collected, a total of 27 subsite samples for a plot.

Generally, the quantities allowable for loan are selectable from the following categories (0-10g, 10-20g, 20-60g, 60g-100g). The quantity required for loan will be dependant on the type of analyses required.

Soil metagenomic samples

Soil metagenomic samples are collected from the top layer of soil at each of the 9 subsites within each plot (see diagram below). Samples can be used for DNA analysis to determine species present. Each sample is placed in a calico bag, which is then stored within a sealed bag containing silica gel. The silica gel is monitored and replaced as necessary. The samples are kept in the cool room of the TERN Australia Soil and Herbarium Collection at 17^oC. For the 9 metagenomic samples collected at a plot ~200g is collected.

Generally, the quantities allowable for loan are selectable from the following categories (<0.5g, 1-3g, 4-10g). The quantity required for loan will be dependant on the type of analyses required.

Further Information

For more information about the sampling protocols used for each sample type, please see the AusPlots Rangelands Manual v1.2.9.