Victorian Alpine Plot Network (ATEX): Invertebrate Pitfall Trapping, 2007

Plot set-up The Victorian Alpine Plot Network Vegetation Data Package contains vegetation data for four sites situated on the Bogong High Plains. Sites, which comprise multiple 1 square metre plots, are visited every second snow-free season. Following the International Tundra Experiment (ITEX) protocol (Molau and Mølgaard 1996; Jarrad et al. 2009; Wahren et al. 2013), four open-heathland ATEX field sites, two burnt and two unburnt, were established in the Rocky Knobs area (36.90ºS, 147.27ºE) on the Bogong High Plains in 2003. The burnt and unburnt sites were ca. 1.7 km apart while within burn-type, each of the sites were separated by approximately 0.5 km. At each of the two unburnt sites, 26 x 1 m2 plots are located along permanently marked transects. Transects are 10 m apart, 50 m long, and are marked with sturdy, red gum end-pegs. At each unburnt site, 13 of the plots are covered by a hexagonal open-topped chamber (OTC; base diameter 168 cm, top diameter 110 cm) and the remaining, control plots are uncovered. At each of the two burnt sites there are 14 x 1 m2 plots, seven of which are covered by an OTC, and seven of which are uncovered, controls.

Red gum end-pegs

Hexagonal open-topped chambers (OTCs) The OTCs, which increase ambient temperatures inside the chambers at these sites by about 2 – 2.5°C, are constructed from lightweight, shatter-resistant fibreglass with high light transmittance (86%) and low transmittance of infra-red (<5%). The OTCs for this project are about 50 cm tall, with 110 cm diameter open-tops, and bases 170 cm wide. This size is large enough to accommodate all species to be monitored, without influencing growth habits or reproductive structures via, e.g. edge effects..

Data Collection The data collected is used to assess the diversity of ground-dwelling arthopods. Three or four pitfall traps within each plot are used to capture arthropods. Traps are constructed from plastic sleeves (22 mm diameter, 150 mm deep) and are sunk 150 mm into the ground using a specially designed pin. A glass test tube (20 mm diameter, 120 mm deep) containing 50 mm of propylene glycol and ethanol (1:1) is placed inside the sleeve so that the top of the trap is flush or slightly below the soil surface (method adapted from Majer 1978). Sleeves are sealed with foam plugs when test tubes are not in place. A seven-day sampling period occurs three times during the snow-free season (October to April). The same points are used each season.

Pitfall traps See: Molau U, Mølgaard P (1996) 'International Tundra Experiment (ITEX) Manual.' (Danish Polar Center: Copenhagen, Denmark) NA