Biodiversity benefits of China’s 20-year efforts in forest restoration

China has become a global leader in forest restoration, through massive investment and various large-scale programs since 2000. Nevertheless, the overall biodiversity outcomes of these efforts remain to be quantified. Here, using 402 non-migratory forest bird species as indicators, we assess biodiversity changes from 2000 to 2020 at a national scale, controlling for the effects of climate change by using an ecological niche modeling framework. We find substantial biodiversity benefits linked to the expansion of forest extent and the improvement in forest structure, with 73.6% of avian species experiencing habitat expansion and mean species richness increasing by 2.886 ± 8.418. Protection-focused and afforestation-dominated restoration programs both effectively enhanced biodiversity, with planted forests performing similarly to natural forests over this period. Key factors facilitating this enhancement included tree cover and canopy structural complexity. Our findings suggest that restoring planted forests in degraded landscapes can provide substantial biodiversity benefits, although this should incorporate mixed tree species silviculture practices to enhance the structural complexity of planted forests. This study highlights China’s achievements but also the potential risks involved in forest and biodiversity restoration, and provides general insights for the optimization of future restoration policy and management in China and beyond.