## 4 Results  
### Trends in Vegetation Phenology and Growing Season Integral  
More pixels of the NH with significant linear trends in LOS (Figure 2C) (42.45%) were observed as compared to SOS (Figure 2A) (34.83%), and EOS (Figure 2B) (41.37%) (Table 2). Moreover, most areas show opposite spatial patterns in trends in SOS and LOS (Figure 2A,C), but consistent pattern in EOS and LOS trends (Figure 2B,C). The quantitative assessment and spatial patterns indicate that extending LOS in the NH is caused by both advancing SOS and delaying EOS in most regions, whereas shortening LOS is due to both delaying SOS and advancing EOS.  
Areas of pixels of the NH with significant positive trends in GSI (Figure 2D) (51.22%) are considerably larger than those in LOS (23.24%) (Table 2), whereas the areas of pixels with negative trends in GSI (9.95%) are much smaller than those in LOS (19.21%) (Table 2). This suggests that areas of significant greening trends are dominating the NH, with LOS appearing comparably mixed in lengthening and shortening trends over the past three decades, indicating that some areas are experiencing increasing vegetation productivity without significant changes in LOS.  
At the continental scale, North America (NA) is dominated by significant decreasing trends in LOS, but Eurasia (EA) is dominated by increasing trends (Figure 2C and Table 2). This pattern can be explained by the predominance of significant increasing trends in SOS in NA (28.05%) combined with  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & **NH** & & **NA** & & **EA** & \\ \cline{3-8}  & & **n** & **\%** & **n** & **\%** & **n** & **\%** \\ \hline \multirow{3}{*}{SOS} & \(\mathbf{-1}\) & 222,284 & 20.12\% & 28,047 & 8.04\% & 194,237 & 25.68\% \\  & **0** & 720,201 & 65.18\% & 222,842 & 63.91\% & 497,359 & 65.76\% \\  & **1** & 162,534 & 14.71\% & 97,805 & 28.05\% & 64,729 & 8.56\% \\  & **Total** & 1,105,019 & & 348,694 & & 756,325 & \\ \hline \multirow{3}{*}{EOS} & \(\mathbf{-1}\) & 219,735 & 19.88\% & 75,176 & 21.56\% & 144,559 & 19.11\% \\  & **0** & 647,959 & 58.63\% & 190,661 & 54.67\% & 457,298 & 60.46\% \\  & **1** & 237,469 & 21.49\% & 82,922 & 23.78\% & 154,547 & 20.43\% \\  & **Total** & 1,105,163 & & 348,759 & & 756,404 & \\ \hline \multirow{3}{*}{LOS} & \(\mathbf{-1}\) & 212,287 & 19.21\% & 94,887 & 27.22\% & 117,400 & 15.52\% \\  & **0** & 635,821 & 57.54\% & 198,412 & 56.91\% & 437,409 & 57.84\% \\  & **1** & 256,837 & 23.24\% & 55,353 & 15.88\% & 201,484 & 26.64\% \\  & **Total** & 1,104,945 & & 348,652 & & 756,293 & \\ \hline \multirow{3}{*}{GSI} & \(\mathbf{-1}\) & 109,928 & 9.95\% & 47,106 & 13.51\% & 62,822 & 8.30\% \\  & **0** & 429,265 & 38.83\% & 140,442 & 40.27\% & 288,823 & 38.17\% \\ \cline{1-1}  & **1** & 566,166 & 51.22\% & 161,204 & 46.22\% & 404,962 & 53.52\% \\ \cline{1-1}  & **Total** & 1,105,359 & & 348,752 & & 756,607 & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Statistics (number of pixels and percentages) of significant trends in vegetation metrics (phenology (Figure 2A–C) and growing season integral (Figure 2D)) during 1982–2013 at hemispheric and continental scales. (\(-\)1: significant negative trends, +1: significant positive trends, 0: non-significant trends (\(p=0.1\))).  
relatively large areas of decreasing trends in EOS (21.56%) (comparable to increasing trends (23.8%) in EOS) (Table 2). In contrast, EA is dominated by significant decreasing trends in SOS (25.68%), and has slightly larger areas with positive trends in EOS (20.43%) when compared to negative trends (19.11%). For GSI (Figure 2D), the areas of pixels with significant positive trends are a little smaller in NA than those of EA, whereas pixels of NA with negative trends are slightly larger than those in EA (Table 2). The difference between pixels of GSI with significant positive and negative trends in EA (53.52%/8.30%) is considerably larger than that in NA (46.22%/13.51%), suggesting that the spatial pattern of trends in vegetation productivity is more divergent in NA than in EA.