Seasonal Response of Grasslands to Climate Change Figure 11. Correlations of monthly temperatures (left) and precipitation (right) with vegetation activity during grassland senescence (as measured by the NDVI) on the Tibetan Plateau, according to Partial Least Squares (PLS) regression. For each variable, pixels for which the variable-importance-in-the-projection score was,0.8 are shown in gray. Pixels with insufficient data for PLS analysis are shown in white. doi:10.1371/journal.pone.0049230.g011 PLOS ONE | www.plosone.org 12 November 2012 | Volume 7 | Issue 11 | e49230