Warra Tall Eucalypt Relative Vascular Plant Cover Data 

This data contains relative species cover of vascular plants in plots of either mature tall, wet eucalypt forest or of 25-50 year-old silvicultural regeneration following clearfell harvesting in the Warra Tall Eucalypt site between 2010 - 2011 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. 

The dataset was collected as part of a broader study examining the responses of bird, plant and beetle species to the intensity of disturbance in the landscape. The study tested the null hypotheses that species persisting in patches of mature forest or recolonising patches of silvicultural regeneration would be insensitive to the intensity of disturbance in the surrounding landscape. 

Selection of sample plots:
The three-scale consistent LDI map of the SFEFL was overlain with the mapped extent of two forest age-classes: (i) mature eucalypt forest > 110 years old and never harvested; and (ii) older (25–50 years-old) wet eucalypt forest that had been silviculturally regenerated after clearfell harvesting. Patches of these age-classes coinciding with pixels that were three-scale consistent for LDI class were identified. All locations of scale-consistent patches of mature eucalypt forest and older silvicultural regeneration were prioritised for field validation according to the following criteria:i. Low altitude (below 600 m); ii. Forest dominated by Eucalyptus obliqua, Eucalyptus regnans , or a mixture of these species; iii. At least 75 m from a road, vehicle track, or edge of a strongly contrasting vegetation type; and iv. Forest patch of an age-class was at least 150 m wide at a point where a plot could be located. The final experimental design comprised seven replicate 50 x 50 m square plots of mature eucalypt forest (MAT plots) at each of four LDI classes (4–7), and seven replicate plots of older silvicultural regeneration (SILV plots) at each of four LDI classes (5–8). Mature forest within highly disturbed areas with LDI class 8 was rare, as was older silvicultural regeneration within relatively undisturbed areas with LDI class 4, so these combinations were not sampled.
Calculation of landscape disturbance intensity:
A vegetation map of the SFEFL representing the 2009 distribution of nine broad vegetation classes was produced at 1:20,000 scale from forest-types interpreted from aerial photography acquired in the 2000s (Forestry Tasmania, Forest Class 2005 mapping), and converted to 50 m pixel raster format using the open-source GIS software SAGA©. Each vegetation class was assigned a disturbance rating between 1 (least disturbed) for rainforest and 10 (most disturbed) for agricultural land, and each pixel was assigned the disturbance rating corresponding to its vegetation class. Using a moving-window algorithm, the Landscape Disturbance Index (LDI) for each pixel was then calculated by averaging the disturbance rating of all pixels within a given radius of that pixel. Separate LDIs were calculated for radii of 500 m, 1 km and 2 km, to give separate LDI values for each pixel at these three landscape-scales. All LDI values were rounded down to the nearest integer and the raster maps of integer LDIs at each of the three spatial scales were overlaid to identify pixels with the same integer LDI at each of the three spatial scales to produce a “three-scale-consistent LDI” map of the SFEFL.
Vascular plant surveys:
Six 10 x 10 m subplots were selected within each of the 56 plots for detailed floristic assessment using a method of non-replacement random sampling subject to two conditions: (i) subplots were excluded if they shared a 10-m boundary with a previously selected subplot; and (ii) at least two 10 x 10 m corner regions were sampled. Plot percentage foliage cover (PFC) for each observed species was estimated as the mean PFC of all six subplots at 14 plots, of five of the six subplots at 38 plots, and of four of the six subplots in the remaining four plots. A presence/absence species list was recorded in the subplots where PFC was not estimated, and species that were in presence/absence subplots but not in any of the PFC subplots were assigned a plot cover of 0.5% (the minimum cover score typical of infrequently occurring species). Relative cover was calculated for each species as the PFC of the species as a proportion of the total PFC of all species.