|  | Low Susceptibility to Bias | High Susceptibility to Bias |
---|---|---|---|
Study design | Study season, length | Long (>3 months) study period, multiple seasons | Short (<3 months) study period, winter measurement |
Intervention timescale | Long-term intervention maintained for multiple years | Intervention in place for <2 years | |
Replication, randomisation | Replication at level of intervention, large sample size (>3), some degree of randomisation in sample selection | Pseudoreplicated, low sample size (<3), no randomisation | |
Control matching | Control and treatment/exposure samples well-matched (i.e. close in proximity but low chance of spillover effects) | No evidence of matching, potentially influential differences between treatment and control | |
Clarity and detail of methods | General study design very clear and repeatable | Some missing information | |
Specific methodology | Eddy covariance measurement details | Full description of methodology, accounting for wind direction/speed | Some missing methodological detail, no accounting for wind direction/speed |
Flux chamber measurement details | Full description of methodology, measurement disturbance mitigation measures | Some missing methodological detail, no mitigation for measurement disturbance | |
Soil porewater/air measurement details | Full description of methodology, representative sampling | Some missing methodological detail, sampling unlikely to be representative of variability in environment | |
Surface water measurement details | Full description of methodology, representative sampling | Some missing methodological detail, sampling unlikely to be representative of variability in environment | |
Bias | Potential measurement bias | Measurement bias unlikely or evidently not present | Bias likely as a result of methodology |
Presence of confounders | No obvious confounders stated or evident, or stated but adequately accounted for | Confounders stated and unaccounted for or likely to be present | |
Unclear classification given to any study where substantial details within the methods are either unclear of missing. |