Fig. 3: Spatial correlations between the dendrohydrological reconstructions and the gridded NDVI dataset62.
From: Ecological and societal effects of Central Asian streamflow variation over the past eight centuries
a Correlation patterns of the streamflow reconstruction with August-October NDVI, a satellite-derived measure of grassland productivity, over their period of overlap (1981–2009). Insignificant correlations (P> 0.05) are masked out. The mouse icons indicate that the rodent population density increased under the good vegetation and water conditions in Central Asia. The inset figure shows the comparison between regional NDVI (averaged over 39–45°N, 77.5–86.5°E) and reconstructed streamflow (this study). b Correlation patterns of the PDSI reconstruction of the Mediterranean Basin with July–September NDVI. The mouse icons and arrows show that poor vegetation conditions in Central Asian steppe (blue shape) forced the rodent to migrate to the Mediterranean basin and Western Asia (red circle) with the good vegetation and water conditions. The inset figure shows the comparison between regional NDVI (averaged over 30–45°N, −5–37°E) and reconstructed PDSI16. The numbers in parentheses in the maps indicating the recorded time of plague outbreaks per city.
