A global consistent positive effect of urban green area size on bird richness

Table 3 Results of a weighted mixed-model meta-analysis assessing how the slope (z) of the power species-area relationship model varies between urban green areas in different cities, in relation to continuous and categorical moderator variables

Variable	Q	df	P	Fail-safe number
Population	0.01	45	0.378	3069
Foundation	1.98	45	0.068	3128
Latitude	5.94	45	0.961	3317
Season	1.51	45	0.512	3093
Biome^a	8.77	43	0.334	2984
Methodology aspects	1.14	45	0.600	2999
Bird survey method	5.71	42	0.098	1918
Range of area size	0.32	45	0.176	3105
Minimum area size	0.03	45	0.296	3129
Maximum area size	0.65	45	0.114	3134
Number of green areas^b	0.50	45	0.561	3032
Isolation 1	0.05	34	0.289	764
Isolation 2^b	0.10	37	0.083	1027
Migrants	0.10	36	0.748	1813
Ground nester	5.11	36	0.978	1897
Body size	0.01	36	0.933	1831
Minimum bird richness	1.08	45	0.139	3215
Maximum bird richness	0.05	45	0.139	3115
Bird richness range	0.59	45	0.725	3075

The Q test (Q), degrees of freedom (df), P values and the fail-safe numbers are shown
^aBiomes with only a single case study were excluded from the analysis
^bTest performed after excluding a case study with exceptional distance to rural areas

ISSN: 2053-7166