Table 2.

Confidence level categories and how often they have been chosen.

Confidence levels	Number of cases
High - Reliable/high quality data sources on impact. The case was reviewed and verified by an expert.	1786
Medium - Reliable/medium quality data sources of impact. The impact was either reported by a reliable forester but could not be reviewed and verified by an expert or it was published in a professional journal, but it is not clear from the publication that it was checked by an expert.	189
Low - Low quality data sources of impact. Observation was reported by a non-professional or reported in a non-professional journal, without being confirmed by an expert.	265
NA	64