Table 3 Overall assessment of study validity/risk of bias

Studies were assigned Low validity if any of the following factors applied

Any of these questions answered with “No” or “Unclear”

• Did the study have a temporal and/or spatial control?

• Degree of replication appropriate and representative?

OR

Any of these questions answered with “No”

• Does treatment allocation account for spatial heterogeneity? and/or Intervention and comparator sites well-matched

• No severely confounding factors present? apart from those present at baseline

• Intervention was likely appropriately and realistically applied?

• Outcome measure method was appropriate?

• Study methodology and results are generalisable to other prescribed burns in temperate or boreal forest

Studies that were not assigned Low validity were considered to have Medium validity or Medium (unclear) validity if any of the following factors applied

Any of these questions answered with “Partly”

• Did the study have a temporal and/or spatial control?

• Degree of replication appropriate and representative? (to outcome measure)

OR

Any of these questions answered with “Partly” or “Unclear”:

• Does treatment allocation account for spatial heterogeneity? and/or Intervention and comparator sites well-matched

• No severely confounding factors present? apart from those present at baseline

• Intervention was likely appropriately and realistically applied?

• Outcome measure method was appropriate?

• Study methodology and results are generalisable to other prescribed burns in temperate or boreal forest