Both Current and Historical Landscape Patterns Impact Plant Diversity Across Different Vegetation Types

Aim Impacts of landscape pattern on plant diversity have attracted widespread attention worldwide. This study used a globally standardised plant community database to explore the impacts of both current and historical landscape patterns on plant alpha and beta diversity across different vegetation types which have not been explored before, via examining the associations among plant species. Location Global. Time Period 1990–2020. Major Taxa Studied Vascular plants. Methods We used random forest modelling to select the most influencing landscape metrics, the partial least squares‐based structural equation modelling (PLS‐SEM) analysis to identify the direct and indirect impacts of current and historical landscape patterns, climate factors, and plant species co‐occurrence networks on plant species diversity. Results The results indicate that historical declines in landscape diversity and increases in fragmentation positively influence plant beta diversity. Landscape diversity metrics (e.g., patch richness [PR], patch richness density [PRD]) strongly explain plant alpha diversity by affecting nodes and links in plant species co‐occurrence networks. In contrast, landscape fragmentation metrics (e.g., Number of Patches [NumP], Edge Density [ED], Total Edge [TE]), landscape complexity metrics (e.g., Area‐Weighted Mean Shape Index [AWMSI], Landscape Shape Index [LSI], Mean Patch Fractal Dimension [MPFD], Area‐Weighted Mean Patch Fractal Dimension [AWMPFD]), and area metrics (e.g., Mean Core Area Index [MCAI], Number of Core Areas [NCA]) strongly explain plant beta diversity by influencing dispersal connectivity and modularity in plant networks. Landscape patterns from 5 to 10 years ago had stronger impacts on plant diversity than current patterns. Landscape diversity exhibited the strongest effect on plant alpha diversity, primarily through indirect pathways via plant networks. Landscape fragmentation and patch area had the strongest effects on plant beta diversity, with indirect or direct impacts on its two components (species turnover and nested differentiation) varying across vegetation types. Main Conclusions To safeguard plant alpha diversity, prioritising landscape diversity is essential; for plant beta diversity, managing landscape fragmentation remains critical. These strategies must be balanced while simultaneously accounting for plant network traits and historical landscape contexts across varying vegetation types.