Soubeyrand S, Laine A-L, Hanski I, Penttinen A
Institut National de la Recherche Agronomique, UR546 Biostatistics and Spatial Processes, 84914 Avignon, France.
Am Nat. 2009 Sep;174(3):308-20. doi: 10.1086/603624.
The ecological and evolutionary dynamics of species are influenced by spatiotemporal variation in population size. Unfortunately, we are usually limited in our ability to investigate the numerical dynamics of natural populations across large spatial scales and over long periods of time. Here we combine mechanistic and statistical approaches to reconstruct continuous-time infection dynamics of an obligate fungal pathogen on the basis of discrete-time occurrence data. The pathogen, Podosphaera plantaginis, infects its host plant, Plantago lanceolata, in a metapopulation setting where the presence of the pathogen has been recorded annually for 6 years in approximately 4,000 host populations across an area of 50 km x 70 km in Finland. The dynamics are driven by strong seasonality, with a high extinction rate during winter and epidemic expansion in summer for local pathogen populations. We are able to identify with our model the regions in the study area where overwintering has been most successful. These overwintering sites represent foci that initiate local epidemics during the growing season. There is striking heterogeneity at the regional scale in both the overwintering success of the pathogen and the encounter intensity between the host and the pathogen. Such heterogeneity has profound implications for the coevolutionary dynamics of the interaction.
物种的生态和进化动态受到种群数量时空变化的影响。不幸的是，我们通常在跨大空间尺度和长时间研究自然种群数量动态方面能力有限。在此，我们结合机械和统计方法，基于离散时间出现数据重建专性真菌病原体的连续时间感染动态。病原体白粉菌感染其寄主植物披针叶车前，在一个集合种群环境中，在芬兰50公里×70公里区域内约4000个寄主种群中，已对该病原体的存在情况进行了连续6年的年度记录。动态变化受强烈季节性驱动，当地病原体种群在冬季灭绝率高，在夏季流行扩散。我们能够通过模型识别研究区域内越冬最成功的区域。这些越冬地点是生长季节引发局部流行的疫源地。在区域尺度上，病原体的越冬成功率以及寄主与病原体之间的相遇强度都存在显著的异质性。这种异质性对相互作用的协同进化动态具有深远影响。
