EFFECTS OF CLIMATE-CHANGE ON EUROPE-WIDE WINTER-WHEAT AND SUNFLOWER PRODUCTIVITY

Spatially explicit crop models were developed from mechanistic princip les to investigate the regional impacts of climate change. The approac h highlights the spatial variability of crop responses to altered envi ronmental conditions. The mechanistic nature of the models allows some confidence to be placed in the results that are produced under climat e change scenarios. Two crop models have been constructed and applied across a large European region: EuroWheat (winter wheat) and EuroSunfl (sunflower). Model results were compared with observed phenology and yield across a variety of scales and found to capture the current spat ial variability in wheat and sunflower productivity. Climate change sc enarios from both equilibrium and transient general circulation model experiments were applied to each crop model. Wheat yields are predicte d to increase throughout Europe for all climate change scenarios. Conv ersely, water-limited sunflower yields decrease in most regions and sc enarios. More positive effects are predicted for winter wheat than sun flower due to a lower sensitivity to increased temperature and a highe r sensitivity to elevated concentrations of CO2. The lowest yield incr eases for wheat and the largest yield decreases for sunflower are foun d in western Europe, whilst the most positive responses for both crops occur in central and eastern Europe. Predictions for southern Europe are highly sensitive both within the region and between the scenarios. The old generation of equilibrium climate change scenarios gives the worst predictions (lowest yield increases or highest yield decreases). More beneficial responses are observed for the new generation of tran sient scenarios for both wheat and sunflower. Area averaged results fo r Europe, based on the United Kingdom Meterorological Office transient experiment (UKTR), indicate a rate of increase in winter wheat yields of 0.2 t ha(-1) decade(-1) up to the 2020s and 0.36 t ha(-1) decade(- 1) beyond. Smaller changes are predicted for sunflower: a rate of decr ease of 0.05 t ha(-1) decade(-1) up to the 2020s followed by an increa se of 0.05 t ha(-1) decade(-1).