Spatiotemporal evolution characteristics of the late frost damage risk to shrubby tea trees in tea region, southwest China from 1971 to 2020.

ABSTRACT

Understanding the spatiotemporal evolution characteristics of the risk of late frost damage has scientific guiding significance for optimizing the regional agricultural production layout and varie-ty tuning. Based on the daily meteorological data of 65 weather stations in the southwest China tea region from 1971 to 2020, we analyzed variation characteristics of the last frost date (LFD), tea bud open date (BOD), and their relationships, constructed frost damage probability index and frost damage severity index of spring shoots of shrubby tea trees, and analyzed the spatiotemporal evolution chara-cteristics of the late frost damage risk of shrub tea trees in the southwest tea region. The results showed that both the BOD and LFD had a significant ahead of trend from 1971 to 2020 and the early rate of the LFD was relatively faster than that of the BOD in the southwest tea region. The number of days that the tea buds were exposed to late frost damage after germination showed an non-significant declining trend. The risk of late frost damage of shrubby tea trees in most parts of the southwest tea region showed a declining trend, but Guizhou tea planting region showed an insignificant increasing trend. The risk of late frost damage to shrubby tea trees was high in the western marginal mountai-nous areas of Sichuan tea region, and the junction of Guizhou and Yunnan tea region. The risk of late frost damage was at low level in Sichuan Basin, southern Yunnan tea region, and southern Guizhou tea region. The risk of late frost damage to shrubby tea trees in the northern and central-eastern parts of Yunnan tea region showed an obvious decreasing trend, but increased significantly in the central and eastern parts of Guizhou tea region.