a decreasing trendp < 0.05
In this context, we found a decreasing trend in the concentrations of Ph (p < 0.05; −0.007% yr −1 ), C 6 (p > 0.05; −0.003% yr −1 ) and Gly (p > 0.05; −0.006% yr −1 ) (Fig. 2b,e , and Table 1 ).
In this context, we found a decreasing trend in the concentrations of Ph (p < 0.05; −0.007% yr −1 ), C 6 (p > 0.05; −0.003% yr −1 ) and Gly (p > 0.05; −0.006% yr −1 ) (Fig. 2b,e , and Table 1 ).
From Table 1 , it is obvious that C 4 shows an increasing trend (+0.003% yr −1 ), whereas those of C 5 –C 12 diacids (particularly, C 5 , C 7 , C 8 , C 9 , and C 12 ) show significant (p < 0.05) decreasing trends during the study period.