Presence-absence survey of terrestrial flora taxa across the Vestfold Hills

The Davis Aerodrome Project (DAP) collected a range of environmental survey data over several field seasons to support a comprehensive environmental assessment of the proposed aerodrome. This data includes flora, fauna, soils, lake ecosystem, nearshore, marine, air quality and meteorological information which has been collected by a number of different methods, and extends across the current Davis Station, proposed aerodrome and supporting infrastructure footprint (Ridge Site), previous sites considered for the aerodrome (Heidemann Valley, Adams Flat), as well as locations across the Vestfold Hills away from any of the proposed developments. Processed presence-absence data based on field surveys and photos of terrestrial flora recorded at 1754 sites across the Vestfold Hills over four summer seasons (2012/13; 2017/18; 2018/19; 2019/20). Taxa were grouped into 8 classes: surface moss, surface lichen, and surface algae included species of each taxa growing on surfaces (sub-aerial); sublithic moss, sublithic lichen, and sublithic algae included species of each taxa growing beneath rocks (sublithic/hypolithic); endolithic algae included algae recorded growing within rocks; and Buellia frigida a species of lichen. Site selection and survey method varied from year to year with some sites being opportunistic sightings or presence only records, therefore not all taxa were observed at all sites. Site definition also varied slightly year to year however could be considered a ~5m radius from GPS coordinates. 2012/13: Over the summer season of 2012/13 only sublithic algae communities (presence only) were recorded in a targeted survey (n = 54), with location recorded using handheld GPS.2017/18 and 2018/19: All floristic communities were opportunistically surveyed over both 2017/18 and 2018/19 summer field seasons. For these surveys the presence of at least one floristic community was recorded at each site and the presence/absence of other taxa then recorded at the same site (within ~5m of coordinates). Location of taxa was recorded using handheld GPS (2017/18: n = 183; 2018/19: n = 1127).2019/20: Over the summer season of 2019/20 a comprehensive stratified random sampling survey of terrestrial floristic communities was undertaken across the Vestfold Hills. Prior to sampling, the Vestfold Hills ice-free region was classified into ten strata based on four physical attributes (elevation, solar radiation (as a proxy for aspect), terrain roughness (based on the relative elevation of an 8m resolution grid cell to its 8 neighbouring cells) and slope). Within each stratum 200 random locations were selected as potential site locations. These were then visited during the field season and presence/absence of floristic communities recorded, however not all sites were visited. If any randomly selected locations were inaccessible, alternative sites nearby were carefully chosen based on similar physical attributes within the same stratum. Additional sites were also surveyed at locations where a taxa was opportunistically encountered during fieldwork. In total 389 sites were surveyed, 277 out of a possible 2000 strata sites (inclusive of 34 alternative sites) and 112 additional locations.