, Toronto, Canada.
Agriculture and Agri-Food Canada, Ottawa, Ontario, K1A 0C6, Canada.
Int J Biometeorol. 2021 Jun;65(6):813-825. doi: 10.1007/s00484-020-02055-z. Epub 2021 Feb 1.
This paper demonstrates the use of climatological data and published information to develop a thaw-freeze/freeze-kill indicator for fruit trees during flowering. In fruit-producing regions, when budding and flowering occur before the last spring freeze, a freeze-kill event can cause substantial losses. As spring onset is occurring earlier with climate change, thaw-freeze events have the potential to become more of a hazard both in terms of current production and in terms of potential adaptation strategies. To model the spring thaw-freeze and its magnitude or intensity, we proposed an indicator based on the accumulation of daily minimum temperature between successive freezing dates and its maximum value over the spring. This indicator was tested on apple and peach production in southern Ontario, Canada, using data from eight climate stations in southern Ontario. The indicator showed promise in its utility in that its magnitude was greater when freezing occurred after blooming and it was demonstrated to be correlated to the estimated blooming dates of apple and peach fruits grown in southern Ontario. The annual series was shown to fit the generalized extreme value distribution thereby allowing the extreme risk to be modelled and the return period to be calculated. It was also shown that the reported thaw-freeze events that caused significant apple and peach losses had a return period on the order of 10 years.
本文展示了如何利用气候数据和已发表的信息，为果树在开花期开发解冻/冻结致死指标。在水果产区，当芽和花在最后一次春季霜冻之前开始时，冻结事件可能会造成重大损失。随着气候变化，春季的开始时间更早，解冻事件无论是对当前的生产还是潜在的适应策略来说，都有可能成为更大的威胁。为了模拟春季的解冻和其幅度或强度，我们提出了一个基于连续冻结日期之间的日最低温度累积和春季最高温度的指标。该指标在加拿大安大略省南部的苹果和桃生产中进行了测试，使用了来自安大略省南部的八个气候站的数据。该指标在其使用方面显示出了一定的前景，因为当开花后发生冻结时，其幅度更大，并且证明与安大略省南部种植的苹果和桃果实的估计开花日期相关。年度系列被证明符合广义极值分布，从而可以对极端风险进行建模并计算其重现期。还表明，导致苹果和桃重大损失的报告解冻事件的重现期约为 10 年。
