Changes in the NPP, precipitation and temperature in the study area between 2001 and 2013.

<p><b>(a)</b> Mean NPP (dotted line), linear regression of the mean NPP (straight line), difference between annual NPP and long-term NPP (histogram), and linear regression of the difference between annual NPP and long-term NPP (straight line). <b>(b)</b> Time series auto-correlation function (acf) of NPP from 2001 to 2013. <b>(c)</b> Mean precipitation (dotted line), linear regression of the mean precipitation (straight line) and difference between annual and long-term precipitation (histogram). <b>(d)</b> Mean temperature (dotted line), linear regression of mean temperature and difference between annual and long-term temperature (histogram).