Altitudinal effects on the quality of green tea in east China: a climate change perspective

Climate change differentially affects tea yield at various altitudes; however, its impact on tea quality is less acknowledged. To understand the divergence in tea quality, we collected green tea samples from five sites (with varying altitude from 212 to 1020 m) on Lushan Mountain in Jiangxi Province, eastern China. Results showed that an increase in cultivation altitude decreased total tea polyphenols (TP) but increased amino acids (AA) concentration, leading to a remarkable decrease in TP/AA, one of the most important parameters that determine the taste of green tea. The constituents of AA, especially theanine, glutamic acid, arginine, serine, gamma-aminobutyric acid and aspartic acid increased with increasing elevational gradients. Nonetheless, the constituents of polyphenolic compounds, especially individual catechins, were differentially altered with the change in cultivation altitude. In particular, with increasing elevation, the epigallocatechin-3-gallate and epicatechin gallate decreased, while the epigallocatechin and gallocatechin gallate increased, that eventually caused no significant variation in the total catechins in different sites. Additionally, the percentage of catechins to TP was increased with increasing altitude. Given that temperature is being increased due to climate change, rising temperatures particularly at lower altitude, perhaps, will deteriorate tea quality as a consequence of climate warming. This observation demands development of effective measures for sustaining green tea quality in the face of climate change.