The relative effectiveness of different grassland restoration methods: A systematic literature search and meta‐analysis

Abstract Active grassland restoration has gained importance in mitigating the dramatic decline of farmnland biodiversity. While there is evidence that such operations are generally effective promoting plant diversity, little known about effectiveness different methods applied. Restoration can differ intensity seed bed preparation, source and method application. In this systematic literature search meta‐analysis, we screened for studies mesic grasslands temperate Europe. We focused on active experiments included a treatment lasted more than 3 years. evaluated influence factors species richness relative to non‐restored controls. found 187 articles investigated outcome aimed at actively restoring grasslands. Most plants, with only 9.6% dealing other organisms (e.g. beetles, pollinating insects). Many papers had be excluded due incomplete data, too short study duration and/or lack an adequate control. This resulted 13 fulfilling our criteria inclusion, yielding total 56 data points meta‐analysis. actions increased by, average, 17.4%, compared The explained significant amount variation richness: seeds originating from speciose donor positive effect. effect was even enhanced when combined commercial mix, whereas mixes alone no did not observe any factors, as type preparation or application method. A seed‐source obtained species‐rich seems key efficient Even though should preferred over seeds, associating natural increases richness. further revealed two major research gaps ecology: deficit long‐term investigations well focusing non‐plant organisms.