Changing regional weather?crop yield relationships across Europe between 1901 and 2012

摘要

Europe is, after Asia, the second largest producer of wheat in the world, and providesthe largest share of barley. Wheat (and to a similar extent, barley) production in Europe increasedby more than 6-fold during the 20th century. During the first half of the 20th century, this wasdriven by expanding the harvested area. This was followed, from the mid-20th century, by a massiveincrease in productivity that in many regions has stalled since 2000. However, it remainsunclear what role climatic factors have played in these changes. Understanding the net impact ofclimatic trends over the past century would also aid in our understanding of the potential impactof future climate changes and in assessments of the potential for adaptation across Europe. In thisstudy, we compiled information from several sources on winter wheat and spring barley yields andclimatological data from 12 countries/regions covering the period from 1901?2012. The studiedarea includes the majority of climatic regions in which wheat and barley are grown (from centralItaly to Finland). We hypothesized that changes in climatic conditions have led to measurableshifts in climate?yield relationships over the past 112 yr, and that presently grown wheat and barleyshow a more pronounced response to adverse weather conditions compared to crops from theearly 20th century. The results confirm that climate?yield relationships have changed significantlyover the period studied, and that in some regions, different predictors have had a greater effect onyields in recent times (between 1991 and 2012) than in previous decades. It is likely that changesin the climate?yield relationship at the local level might be more pronounced than those acrossthe relatively large regions used in this study, as the latter represents aggregations of yields fromvarious agroclimatic and pedoclimatic conditions that may show opposing trends.