Abstract:

Based on the biological characteristics of Litchi chinensis, meteorological observation data and GIS data from 16 stations in Qu county and its surrounding areas, as well as Hejiang county, from 1991 to 2024 were utilized. Through climate simulation analysis and GIS zoning technology, the climatic feasibility of introducing Litchi chinensis to Qu county was systematically evaluated. The annual accumulated temperature, average January temperature, and average annual extreme minimum temperature were selected as indicators, and a comprehensive weighting method was applied to develop a climatic zoning plan for Litchi chinensis introduction. The results indicated that: (1) most areas of Qu county had an average annual temperature of 17.0–17.9°C. In regions below 300 m in elevation, the annual accumulated temperature≥10.0°C exceeded 5500°C·d. It was projected that the flowering and fruiting period of Litchi chinensis in Qu county would be 7–10 days later than that in Hejiang county, indicating climatic potential for introducing late−maturing Litchi chinensis cultivars. However, winter frost was identified as the major limiting factor. (2) The extreme minimum temperature in January in Qu county was recorded as −3.3°C (−2.1°C at an 80% probability level), making it difficult for open−field cultivation to safely overwinter. Meteorological disasters such as midsummer high temperatures (extreme reaching 44.0°C), summer droughts, and torrential rain floods further increased the risks associated with Litchi chinensis introduction. (3) Over the past 34 years, a significant warming trend was observed in Qu county, with the annual accumulated temperature ≥10.0°C increasing significantly (172.46°C·d per decade). However, winter warming was not significant, and the risk of frost remained perennial. Thus, cold protection measures were deemed necessary for Litchi chinensis introduction. (4) Climatic zoning revealed that river valley areas south of 31°N in Qu county with elevations below 300m were suitable for Litchi chinensis introduction, while regions at 300–400m elevation were marginally suitable. Hilly areas above 400m elevation were unsuitable. It was recommended that late−maturing Litchi chinensis introduction be prioritized in areas with elevations below 300m in Qu county. In conjunction with local climatic characteristics, cost−effective winter cold protection technologies should be simultaneously developed. Furthermore, cold protection techniques, cultivar optimization, and industrial resilience should be integrated. Through measures such as facility agriculture, selection of cold−resistant cultivars, and establishment of disaster prevention and control systems, the success rate of Litchi chinensis introduction could be enhanced. Sustainable industrial models were suggested to be gradually explored to avoid blind introduction and expansion.

Key words: Litchi chinensis introduce, Climatic suitability, Frost damage, Climatic zoning, Qu county