Table 4 Scoring sheet for study quality assessment

Selection and Performance bias: Study design

Temporal repetition

Before-After (BA) Time Series (>1 replicates before and after)

25

Interrupted BA Time series (>1 replicates before and after)

20

BA comparison (1 Before, >1 After)

15

BA comparison (>1 Before, 1 After)

12

BA comparison (1 Before, 1 After)

10

Deficient BA comparison (e.g. Before-data from archives or not from exactly the same sites)

1

No BA comparison

0

Spatial repetition

Gradient of intervention intensity including "zero-control"-sites

25

Site comparison (control/impact-CI)

15

Gradient of intervention intensity without "zero-control"-sites

5

Deficient CI comparison (e.g. Control-data from archives or not from the same period)

1

No CI comparison

0

Assessment bias: Measurement of outcome

Replicates per treatment (number of sites)

Well replicated ( >4 replications) objective parameters measured in several floodplain (sections)

20

Well replicated ( >4 replications) objective parameters measured in a single floodplain (sections)

12

Replicated (1– 4 replications) objective parameters measured in several floodplain (sections)

10

Replicated (1– 4 replications) objective parameters measured in a single floodplain (section)

6

Unreplicated observations of objective parameters

2

Data gathered by expert opinion or questionnaire

0

Sampling method

Sampling method perfectly appropriate for purpose

2

Sampling method of restricted suitability

0

Coverage

Large scale (large plots, long sampling sessions or large overall extent) in relation to study aims and studies organisms

2

Intermediate scale in relation to study aims and studies organisms

1

Small scale (small plots, short sampling sessions or small overall extent) in relation to study aims and studies organisms

0

Selection and Performance bias: Baseline comparison (heterogeneity between treatment and control arms with respect to defined confounding factors before treatment)

Sampling

Treatment and control arms homogenous

2

Treatment and control arms not comparable with respect to confounding factors OR insufficient information

0

Species composition

Treatment and control arms homogenous

2

Treatment and control arms not comparable with respect to confounding factors OR insufficient information

0

Habitat type

Treatment and control arms homogenous

2

Treatment and control arms not comparable with respect to confounding factors OR insufficient information

0

Other confounding environmental factors (floods, etc.)

Treatment and control arms homogenous

2

Treatment and control arms not comparable with respect to confounding factors OR insufficient information

0

Selection and Performance bias: Intra treatment variation (heterogeneity within both treatment and control arms with respect to confounding factors)

Location

No heterogeneity within treatment and control arms

2

Replicates within treatment and control arms not comparable

0

Intervention type

No heterogeneity within treatment and control arms

2

Replicates within treatment and control arms not comparable

0

Habitat type

No heterogeneity within treatment and control arms

2

Replicates within treatment and control arms not comparable

0

Reliability of the presented evidence

Overall consistency and clarity of the paper

High

2

Low

0

Statistical approaches appropriate

Yes

2

No

0

Clarity of the description of the method incl. statistical models used

High

2

Low

0

Clarity of the presentation of the results (incl. statistics)

High

2

Low

0

Missing values for nonsignificant results causing publication bias

No

4

Yes

0