川西高原羊肚菌低温冷害特征及风险评估

Characteristics and risk assessment of chilling injury on Morchella esculenta in Western Sichuan Plateau,China

开展羊肚菌低温冷害气候风险精细区划,可为羊肚菌特色农业栽培规划、低温冷害动态评估和防灾减灾对策提供科学依据。基于川西高原海拔3000 m以下17个县(市)2011—2020年气象数据,分析羊肚菌典型年份致灾临界气象条件;选取气温稳定通过5℃初日~10℃初日之间多年平均积寒与冷害频次作为川西高原羊肚菌出菇期间低温冷害区划指标,建立冷害指标的地理空间分布模型,划分川西高原羊肚菌冷害风险等级,评估羊肚菌冷害风险。结果表明:研究区羊肚菌冷害风险温度指标为日最低气温≤2.0℃,日平均气温<6.0℃将导致生长缓慢或者停止生长,设定为冷害风险预警指标。羊肚菌冷害发生频次沿大渡河流域和岷江流域从南向北增多。冷害总次数最少的地区是汶川、茂县、理县,九龙、雅江、巴塘最多。冷害日数以持续1~3 d为主,持续4~5 d次之,持续5 d以上较少,其中,乡城、巴塘、九龙、雅江、小金冷害持续5 d以上的次数多于持续4~5 d的次数。羊肚菌冷害年均日数3.0~27.4 d,冷害发生时段的日均最低气温-0.84~1.36℃、极端最低气温-5.8~0.1℃、平均积寒0.16~9.64℃·d,冷害平均日数、平均积寒随海拔、纬度的增加而增加;冷害最长过程日数是3~20 d,最大积寒0.44~13.34℃·d。羊肚菌冷害风险等级从南向北、由低海拔向高海拔增加。适宜种植区沿山脉河流走向呈带状、枝状分布特征,主要分布在康定、泸定、丹巴、汶川、理县、茂县、九寨沟、松潘等海拔2200 m以下的低山河谷平坝区。

The development of precise climate risk zoning for chilling injury of Morchella esculenta can provide scientific basis for agricultural cultivation planning,dynamic assessment of chilling injury,and disaster prevention strategies.Based on meteorological data from 17 counties(cities)that located below the altitude of 3000 m in the Western Sichuan Plateau from 2011 to 2020,we analyzed the critical meteorological conditions for M.esculenta disasters in typical years.With the average yearly cold accumulation and cold injury frequency during the first day when the temperature remained stable between 5℃and 10℃during mushroom emergence as zoning indicators,we established a geographical spatial distribution model of the cold injury index,and then divided the risk level of M.esculenta cold injury in the Western Sichuan Plateau,evaluated the risk of cold injury.The results showed that the temperature index for chilling injury risk of M.esculenta in the study area was the daily minimum temperature≤2.0℃.The daily average temperature<6.0℃would cause slow growth or the cessation of growth,which was set as a warning indicator for chilling injury risk.Along the Dadu River and Minjiang River basins,the frequency of chilling injury on M.esculenta increased from south to north.Wenchuan,Maoxian,and Lixian had the fewest overall chilling injuries during the study period,whereas Jiulong,Yajiang,and Batang had the most.The duration for cold injury was mainly 1-3 d,followed by 4-5 d,and rarely for>5 d.The frequency of chilling injury lasting for more than 5 d in Xiangcheng,Batang,Jiulong,Yajiang,and Xiaojin was more than that lasting for 4-5 d.The annual average days of chilling injury of was 3.0-27.4 d,the daily average minimum temperature was-0.84-1.36℃,the extreme lowest temperature was-5.8-0.1℃,and the average accumulated cold was 0.16-9.64℃·d during the period of chilling injury.With the increases of elevation and latitude,the average days of chilling injury and the average accumulated cold increased.The largest duration of chilling injury was 3-20 d,the maximum accumulated cold was 0.44-13.34℃·d.The risk of chilling injury to M.esculenta increased from south to north and from low elevation to high elevation.The suitable planting areas were distributed in strips and branches along the direction of mountains and rivers,mainly in the flat areas of low mountains and valleys below the altitude of 2200 m,including Kangding,Luding,Danba,Wenchuan,Lixian,Maoxian,Jiuzhaigou,and Songpan.