UMR1136 'Interactions Arbres/Micro-organismes', INRA, INRA-Nancy, Champenoux, 54280, France; UMR1136 'Interactions Arbres/Micro-organismes', Université de Lorraine, INRA-Nancy, Champenoux, 54280, France.
Glob Chang Biol. 2014 Oct;20(10):3209-21. doi: 10.1111/gcb.12601. Epub 2014 May 22.
Alder decline caused by Phytophthora alni is one of the most important emerging diseases in natural ecosystems in Europe, where it has threatened riparian ecosystems for the past 20 years. Environmental factors, such as mean site temperature and soil characteristics, play an important role in the occurrence of the disease. The objective of the present work was to model and forecast the effect of environment on the severity of alder Phytophthora outbreaks, and to determine whether recent climate change might explain the disease emergence. Two alder sites networks in NE and SW France were surveyed to assess the crown health of trees; the oomycete soil inoculum was also monitored in the NE network. The main factors explaining the temporal annual variation in alder crown decline or crown recovery were the mean previous winter and previous summer temperatures. Both low winter temperatures and high summer temperatures were unfavorable to the disease. Cold winters promoted tree recovery because of poor survival of the pathogen, while hot summer temperature limited the incidence of tree decline. An SIS model explaining the dynamics of the P. alni-induced alder decline was developed using the data of the NE site network and validated using the SW site network. This model was then used to simulate the frequency of declining alder over time with historical climate data. The last 40 years' weather conditions have been generally favorable to the establishment of the disease, indicating that others factors may be implicated in its emergence. The model, however, showed that the climate of SW France was much more favorable for the disease than that of the Northeast, because it seldom limited the overwintering of the pathogen. Depending on the European area, climate change could either enhance or decrease the severity of the alder decline.
由于栗疫病菌（Phytophthora alni）引起的桤木衰退是欧洲自然生态系统中最重要的新兴疾病之一，在过去的 20 年里，它已经威胁到了河岸生态系统。环境因素，如平均站点温度和土壤特性，在疾病的发生中起着重要作用。本工作的目的是建立和预测环境对桤木疫病菌暴发严重程度的影响，并确定最近的气候变化是否可以解释该疾病的出现。对法国东北部和西南部的两个桤木网络进行了调查，以评估树木的树冠健康状况；在东北部网络中还监测了卵菌土壤接种体。解释桤木树冠衰退或树冠恢复的年度时间变化的主要因素是前冬和前夏的平均温度。低温和高温都不利于疾病的发生。寒冷的冬季有利于树木的恢复，因为病原体的存活率较低，而炎热的夏季气温限制了树木衰退的发生。使用东北部网络的数据开发了一个解释 P. alni 诱导的桤木衰退动态的 SIS 模型，并使用西南部网络的数据对其进行了验证。然后，使用该模型根据历史气候数据模拟随时间推移而衰退的桤木的频率。过去 40 年的天气条件总体上有利于该疾病的建立，这表明可能还有其他因素与该疾病的出现有关。然而，该模型表明，法国西南部的气候比东北部更有利于该疾病，因为它很少限制病原体的越冬。根据欧洲地区的不同，气候变化可能会增强或降低桤木衰退的严重程度。
