Fig 1.
Specific to this meta-analysis, from Moher et al. [37].
Fig 2.
World map showing the geographical disposition of the studies used in this meta-analysis.
(1) Aroviita and Hämäläinen (2008) [39], (2) Valdovinos et al. (2007) [20], (3) Marchetti et al. (2011) [26], (4) Molozzi et al. (2013) [40], (5) Takao et al. (2008) [15], (6) Kullasoot et al. (2017) [16], (7) White et al. (2011) [22], (8) Smokorowski et al. (2011) [25], (9) Englund and Malmqvist (1996) [18], (10) Jackson et al. (2007) [14], (11) Kraft (1988) [17], (12) Mellado-Diaz et al. (2019) [41], (13) Bruno et al. (2019) [42], (14) Milner et al. (2019) [43], (15) Steel et al. (2018) [44], (16) Schneider and Petrin (2017) [45], (17) Vaikasas et al. (2013) [46], (18) Doledec et al. (2021) [47], (19) Wang et al. (2016) [48], (20) Nukazawa et al. (2020) [49], (21) Quadroni et al. (2020) [50], (22) Vilenica et al. (2020) [51], (23) Uieda and Marcal (2020) [52] and (24) Cazaubon and Giudicelli (1999) [53].
Fig 3.
Forest plot of the meta-analysis.
The mean effect size is -0.84 (95% CI = -1.62 to -0.05, shaded grey area), where study type is shape-coded (i.e., circle for longitudinal studies and squares for cross-sectional studies) and biome color coded (i.e., boreal in blue, temperate in yellow and tropical in red). A negative effect size means that there is a negative impact of hydropower in impacted sites as opposed to reference sites, whereas a positive effect size means that there is positive impact of hydropower in impacted sites as opposed to reference sites.
Fig 4.
Plots showing the mean effect sizes and their confidence interval for each of the moderators.
Value in black is the mean effect size of the meta-analysis and the other colors are related to the different effect sizes when including specific moderators. When in grey, statistical significance of moderator cannot be interpreted with confidence due to statistical power issues (dfs insufficient). When effect size is in color (i.e., blue) statistical interpretation can be made with confidence, whether it is significant or not (sufficient dfs). Asterisk signifies statistically marginally significant effect.