Fig. 8
The effect directions of temperature on some aspects of vertebrate gut bacterial community found in 18 studies and 17 species. Literature sources and data, including some additional data, are presented in Additional file 1: Table S3. A positive effect direction ( +) indicates an increase with temperature or a significant difference in beta-diversity, a negative effect direction ( − ) indicates a decrease with temperature (does not apply to beta-diversity), and the 0 indicates no significant effect. Circle size represents the percentage of studies with that effect direction within the studies that reported on the concerned index; this percentage is specified by the numbers near the circles. The number of studies that presented data for the given taxa, alpha- and beta-diversity indices are indicated between brackets under the X-axe labels