LTERN Data Portal

The Victorian Alpine Plot Network Plot-data Package contains plot-data collected at eighty-nine sites situated in the Australian Alps. Randomly positioned transects are situated within sites rather than ‘plots’ sensu stricto. Each site, and/or transect geo-located, and point quadrats are taken at fixed intervals along each transect using a 4 mm diameter steel pin inserted vertically into the vegetation. The number of transects within sites, and sampling frequency varies from annual to decadal, depending on site and purpose. The number of transects within sites, and sampling frequency varies from annual to decadal, depending on site and purpose.

Long Term Vegetation monitoring sites - grasslands, heathlands, snowpatch herbfields and wetlands:

Establishment of these long-term monitoring sites commenced in the late 1970’s on the Bogong High Plains. In ensuing decades, more sites have been established on the Bogong High Plains, Dargo High Plains and Holmes/Wellington (Wahren et al. 1994; Wahren et al. 1999; Wahren et al. 2001a; Wahren et al. 2001c; Williams et al. 2012; Wahren et al. 2013). Sites have been established in all of the major vegetation types – grasslands, heathlands, snowpatch herbfields and wetlands. In the grasslands, each site is ca. 0.5-1 ha in area, with 10-12 10 m transects per site. Transects are located randomly within sites and point quadrats are taken at 20 cm intervals along each transect. This gives a total of 50 points per 10m transect, and 500-600 points per site. All species touching the pin are recorded, along with the state of the ground surface (whether bare, or covered by litter). At present there are 17 monitoring sites established in grassland on the Bogong High Plains and five at Holmes and Wellington Plains.

A similar array of transects within sites has been established at 45 snowpatch herbfields sites across the Bogong High Plains. At each site the sampling regime is the same as for grasslands – 10 x 10 m transects, with 50 point quadrats per transect. Complementary floristic data are also collected at each site from five to fifteen 3 x 2 m quadrats that are randomly located within each snow patch.

Quadrat size was determined using species-area relationships for a range of quadrat sizes (0.1-20 m2; (Swengel 2001)). Within each quadrat, all species are identified and the cover of each is estimated visually using the Braun-Blanquet scale (Wahren et al. 2001a).

This general array of sampling transects, point quadrats along transects and floristic quadrats is consistent between grassland and snowpatch monitoring sites. However, the number of transects and floristic quadrats needed to detect change at each site varies. The optimal number per site has been determined by power analysis to adequately sample the composition and structure of the grassland and snowpatch communities, and detect change in key variables (vegetation cover, bare ground, etc) over time. There are also long-term monitoring sites in wetlands. These include two sites at the head of Middle Creek on the Bogong High Plains.