Table 2 Variables used in analysis.
From: Invasive shrub re-establishment following management has contrasting effects on biodiversity
Variable | Description | Range | Type |
|---|---|---|---|
Fixed effects | |||
Fire frequency | Total number of fires recorded as occurring at a site between 1964 and the year of an observation. | 0 to 4 (median = 1) | Integer |
Time since last fire | Time in years (rounded to whole number) since the most recent fire event. | 0 to 33 (median = 8) | Integer |
Spray frequency | Total number of sprays recorded as occurring at a site between 1964 and the year of an observation. | 0 to 7 (median = 2) | Integer |
Time since last spray | Time in years (rounded to whole number) since the most recent spray event. | 0 to 12 (median = 2) | Integer |
Live bitou bush cover (%) | Average cover of live bitou bush per site | 0 to 77 | Integer |
Random effects | |||
“Site”: to account for non-independence from repeated-measures | Site identifier code unique to all 54 monitoring sites included in this study. | — | Factor (54 levels) |
“Site location”: to account for spatial auto-correlation | Broad classification based on whether site is within the zone invaded by bitou bush and subject to management, or not. | Inside Outside | Factor (2 levels) |
“Survey year”: to account of temporal auto-correlation | Year in which monitoring was undertaken (2007–2017). | 1 to 10 | Integer |
