宁夏贺兰山东麓酿酒葡萄越冬期冻害指数及其变化特征

宁夏是中国酿酒葡萄生产最佳生态区之一。但由于宁夏贺兰山东麓的地形及特殊的地理位置,酿酒葡萄在越冬期受到寒潮甚至冻害的威胁,因此酿酒葡萄如何安全越冬成为一大问题。利用位于贺兰山东麓的宁夏自治区永宁县农业气象试验站1980-2016年冬季逐日气温资料,通过对越冬期极端最低气温、低温持续日数(最低气温≤-19℃)、越冬期平均最低气温和越冬期平均气温等气象因子进行标准化处理,运用主成分分析法计算并构建酿酒葡萄越冬期综合冻害指数,应用Mann-Kendall突变检验法和Morlet小波分析法对历年综合冻害指数变化特征进行分析。结果表明,综合冻害指数能较好地反映宁夏贺兰山东麓酿酒葡萄历年冻害情况,综合冻害指数值越小,冻害程度越严重,综合分析后确定综合指数值0为酿酒葡萄出现冻害的临界指标;近36 a来,酿酒葡萄综合冻害指数呈上升趋势,并在1995年左右出现突变;综合冻害指数序列年代际变化以25～30 a左右的周期信号明显,从小波系数大尺度背景来看,正值中心还未闭合,由小波系数正值范围可推测,未来一段时间综合指数仍处于正值区。研究结果对酿酒葡萄冻害监测和预警具有重要指导意义。

Winter Freezing Damage Index and Its Effect on Wine Grapes in Eastern Part of Helan Mountain of Ningxia

Ningxia is one of the best ecological regions for the production of Chinese wine grapes. However, due to the topography and special geographical location of Ningxia, wine grapes are threatened by cold waves and even freezing during the winter, so how to live through winter safely for wine grapes has become a big problem. In this paper, the integrate freezing damage index (IFDX) of Ningxia wine grapes was established based on the daily temperature data at Yongning weather station from 1980 to 2016, including the extreme minimum temperatures in winter, the low temperature duration (lowest temperature≤19℃), the average winter minimum temperature and the average winter temperature by using the principal component analysis. the IFDX feature was analyzed through Mann-Kendall mutation test and Morlet wavelet. The results showed that the IFDX could reflect the freezing damage of wine grapes better in Ningxia Helan Mountain, and the IFDX was smaller, the damage was more serious. The wine grapes reached the critical point to damage when IFDX<0. In the past 36 a, the IFDX of wine grapes was on the rise, and there was a mutation around 1995. The interdecadal variation of IFDX sequence was obvious with a periodic signal about 25~30 a, from the large-scale background of wavelet coefficients, the positive center had not been closed yet. It could be inferred from the positive range of the wavelet coefficients that the composite index would still in the positive area for a period of time in the future. The results could provide direction for monitoring and warning Ningxia wine grapes freezing damage.