Sacred forest biodiversity conservation: A meta-analysis

Sacred forests offer co-benefits of protecting both cultural traditions and forested areas. However, sacred forests' contribution to biodiversity conservation is often undervalued. Several reviews discuss biodiversity conservation in sacred forests, but large-scale studies that quantify the effect of sacred forests on biodiversity conservation are scarce. Many studies on the effectiveness of sacred forests in protecting biodiversity are limited to single-location censuses or lack comparisons against non-sacred forests that serve as controls. To quantify the impact of sacred forests on biodiversity conservation, we conducted a global meta-analysis that compares sacred forests with nearby non-sacred forests (i.e., control areas). Using 35 studies from 17 different countries, we found that sacred forests harbored similar levels of biodiversity as nearby forested areas. When comparing taxonomic groups, we found that the positive benefits to biodiversity in sacred forests compared to non-sacred forests were higher for plants compared to non-plant taxa. Our meta-analysis provides quantitative evidence that sacred forests can be effective areas of biodiversity conservation. Based on our results, we suggest that researchers interested in sacred forest biodiversity compare sacred forests with other land use types, collect standardized metadata from sacred forests and nearby areas that serve as comparisons, and extend monitoring to include more non-plant taxa. Sacred forests can preserve ecosystem function, provide social benefits, and play a role in fighting against climate change, and should not be overlooked.