# Quantifying Climate Change and Ecological Responses within the Yangtze River Basin, China
## 3 Results
### Trends in Ecological Indicators in the YRB
These results indicate that mean annual total GPP was 1905 TgCyr\({}^{-1}\), with a maximum of 1954 TgCyr\({}^{-1}\) in 2004 (49 TgCyr\({}^{-1}\) above the mean) and a minimum of 1775 TgCyr\({}^{-1}\) in 2000 (130 TgCyr\({}^{-1}\) below the mean). Annual total GPP increased from 1775 TgCyr\({}^{-1}\) in 2000 to 1869 TgCyr\({}^{-1}\) in 2010 (Figure 15). Figure 12: Spatial distribution of linear trends in **(a)** mean growing season NDVI, **(b)** mean annual NDVI, **(c)** mean growing season EVI, and **(d)** mean annual EVI in the YRB during 2001–2013. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Variables**} & \multicolumn{4}{c}{**Increasing (slope > 0)**} & \multicolumn{4}{c}{**Decreasing (slope < 0)**} \\ \cline{2-7}  & **Total** & \(p\) **< 0.01** & \(p\) **< 0.05** & **Total** & \(p\) **< 0.01** & \(p\) **< 0.05** \\ \hline Air temperature & 100.00 & 0.06 & 99.94 & - & - & - \\ Precipitation & 58.66 & 3.72 & 11.59 & 41.34 & 3.80 & 4.24 \\ Annualmean NDVI & 65.29 & 9.08 & 13.15 & 34.71 & 2.72 & 2.97 \\ Annualmean EVI & 60.23 & 9.04 & 10.15 & 39.77 & 3.71 & 4.08 \\ Annualmean LAI & 83.35 & 14.05 & 34.08 & 16.65 & 1.05 & 1.07 \\ Annual GPP & 70.04 & 4.20 & 2.79 & 29.96 & 0.27 & 0.37 \\ Annual NPP & 72.77 & 3.42 & 2.38 & 27.23 & 0.16 & 0.53 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Results of trend analysis of meteorological parameters and ecological indicators on the pixel scale. Figure 14: Spatial distribution of (**a**) mean value of LAI in growing season; (**b**) mean value of annual LAI; (**c**) linear fitting of mean LAI changes in growing season; (**d**) linear fitting of annual mean LAI changes in the YRB during 1982–2011. Figure 13: Temporal trends in (**a**) annual mean LAI and (**b**) mean LAI in growing season in the YRB during 1982–2011. Figure 15: Trends of annual total GPP and NPP in the YRB during 2000–2010. Annual total NPP exhibits a slightly increasing trend across the YRB, with an annual rate of change of up to 6 TgCyr\({}^{-1}\)yr\({}^{-1}\). These results indicate that mean annual total NPP was 1076 TgCyr\({}^{-1}\), with a maximum of 1129 TgCy\({}^{-1}\) in 2002 (53 TgCyr\({}^{-1}\) above the mean) and a minimum of 1009 TgCyr\({}^{-1}\) in 2000 (67 TgCyr\({}^{-1}\) below the mean). Annual total NPP increased from 1009 TgCyr\({}^{-1}\) in 2000 to 1069 TgCyr\({}^{-1}\) in 2010 (Figure 15). The areas with lower values of mean annual GPP are mainly in the semi-arid region of sub-frigid zones in the SRYR, and those with higher values are mostly in the Qinba Mountains and the south-eastern hills (Figure 16a). Like the spatial pattern of the mean value of annual GPP, the areas with lower values of mean annual NPP are mainly distributed in semi-arid and semi-humid areas of the sub-frigid zone in the source regions of Gansu, and in eastern Tibet and eastern Sichuan (Figure 16b). The trends in annual GPP and annual NPP show a similar pattern, with an increasing trend in western Sichuan and in the eastern part of Tibet and the Qinba Mountain, and a decreasing trend in the southern hills and the densely urbanized area of the YRD (Figure 16c,d).