Decline in global biodiversity intactness over the past two decades

Knowledge of the dynamics of biodiversity intactness and its spatial differentiation over different geographic regions of the world is crucial for the improved design of effective biodiversity conservation strategies. However, comprehensive investigations of the multiple indicators of biodiversity intactness across several spatial scales are lacking. The current study used an annual time series (2000-2020) of the biodiversity intactness index (BII) to investigate the mean magnitude, temporal trajectory, and relative changes in biodiversity intactness at the national, regional, and global levels. Global mean magnitude of BII was estimated to be 76 ± 16 % between 2000 and 2020, accompanied by the highly diverse BII variations across geographic regions. There has been a gradual decrease in biodiversity intactness over the past 20 years, with the global mean BII trend of -0.3 ± 1.9 %/decade. Africa and Europe have the largest decrease and increase in BII of -1.4 ± 2.2 %/decade and 1.0 ± 1.7 %/decade, respectively. The countries with the top ten BII parameters are mainly located in Africa and Asia, whereas the opposite is true in Europe. The top 10 countries with positive BII trends were mainly in Europe (70 %), followed by Africa (80 %) and Asia (20 %). There was a negative difference between the global mean BII for 2011-2020 and 2000-2010, as evidenced by the relative change in BII of 4.1 %. This study provides an elaborate interpretation of the current status and possible future paths of abundance-based biodiversity intactness at multiple spatial scales, which is beneficial in elucidating biodiversity intactness dynamics and potentially supports biodiversity conservation.