Victorian Alpine Plot Network (Phenology Studies): Vegetation (Insect flower visitors) Data, South-east Highlands, Australia, 2009-2012

Plot set-up Transects were established as a natural experiment - to provide infrastructure to validate the findings from the ATEX manipulated, experimental plots. The aim is to describe the phenological responses of alpine plants to environmental variables and assess the usefulness of this measure to assess vulnerability to changing abiotic (e.g. climate) and biotic (e.g. invasive species) factors. The Victorian Alpine Plot Network research plots commenced in 1996 and were revisited annually for 3 years and then on a decadal basis. These new transects were established in November 2011 to cover a range of elevations. On the Bogong High Plains one set of six transects runs from Buckety Plain to Mt Nelse and another set of plots from Wild Horse Creek to Mt Nelse, with the Mt Nelse point common to both sets. Five sampling transects were also established at Mount Hotham. There are 18 transects in total, which range in altitude from 1400 m to 1880 m. At each site a permanent transect has been established with a geo-located red gum peg marking the start. Transects are sampled on the same dates, three times a year: early season (Bogong High Plains 10-13 November, Hotham 15 November), mid-season (BHPs 17-20 December, Hotham 22 December) and late season (BHPs 18-22 February, Hotham 24 February). Sampling area within transect: A 30 m tape is run from the red gum peg with the temperature sensors in the direction given in Table 1. Each transect is a minimum of 10 m and is mostly be run out to 30 m. Species are recorded along the tape and where necessary within 1 m each side of the tape. If a larger search area is required we continue beyond 30 m and a greater distance either side of the tape. The search area is variable in area so that each species on the data sheet is located, and to ensure that sufficient numbers of individuals are sampled at each site to estimate flowering time.

Data Collection To provide sufficient data on visitations, long quadrats, 1 m by 20 m length, are used to observe insects visiting flowers, adjacent to the plot sites. Wooden stakes 50 mm by 25 mm are used to mark the ends and right hand edge of the quadrats, determined by the peg with the metal label. Where possible the edge along which one walks to record is down slope to the quadrat as this makes observations easier. The floral units for each flowering species are recorded within the quadrat for the entire season, with ten minutes spent observing insect visits for each quadrat. Floral units are defined as non-connected florets. In the case of shrubs this can be difficult to determine so a rough guide is to count the number of stems with flowers and also record the number of individual shrubs flowering within the quadrat. With PIMALP and other similarly structured species the number of flowers can be estimated quite easily but the number of individual plant flowering is also recorded. Recordings are initiated under conditions are suitable for insect activity (not in the rain).

Documentation Plant species are recorded. Insect records follow the same convention, however in most cases identification is at the family level. Given taxonomic restraints, vouchers need to be collected for formal identification purposes; however these need to be limited to minimize disturbance. We use descriptive names for insects tied to vouchers and photos. Vouchers are verified by specialists and are lodged at home institutions.