Patterns and drivers of continent-wide vegetation variability in Africa: Insights from eigen microstates

Vegetation plays a crucial role in regulating global carbon and water cycles. Most existing studies focus on local processes or single factors behind vegetation dynamics, leaving large‑scale patterns and their drivers unclear. A novel statistical physics framework, the eigen microstates method, can identify the collective behaviors of continent-wide vegetation. Specifically, we apply this framework to remote sensing data to identify the dominant patterns of vegetation variability across Africa and use meteorological data to determine their key climatic drivers. The first three eigen microstates collectively explain approximately 74.09% of the observed vegetation variation. The leading pattern (55.87%) captures the strong seasonal NDVI cycle across the continent, with Mediterranean regions showing particularly pronounced seasonal contrasts. The second (10.02%) and third (8.20%) patterns reflect contrasting vegetation dynamics north and south of the equator. Specifically, the second pattern indicates a longer growing season in northern woody ecosystems than in herbaceous systems, whereas the third reveals an earlier onset of the growing season in southern basin regions relative to other areas south of the equator. Our analysis further establishes precipitation and soil moisture as the primary controls on both the magnitude and spatial heterogeneity of vegetation variability. This study provides a continental-scale synthesis of African vegetation dynamics and underscores the critical importance of precipitation regime stability for the stability of the continent's ecosystems.