Impact of global warming on the growing cycles of three forage systems in upland areas of southeastern France

Abstract

The simulations supplied by a combination of a global climate model and a weather generator allowed the creation of two climate scenarios including an increase and/or monthly variations in temperature for the 2070-2100 horizon, which were compared with two currently available series (1961-1990 and 1990-2000). Three forage systems applied in upland areas of southern France were simulated using the STICS model (silage maize, perennial alfalfa and grasses) and the outputs were introduced into a digital elevation model. We noted changes in precocity which allowed the sowing of silage maize varieties with longer crop cycles at lower altitudes and an enlargement of the crop zone above 700-800 m. When introducing monthly temperature variations, we observed major frost damage which decreased maize yields. As for gramineous and alfalfa grasslands, we obtained a lengthening in the growing period with earlier first cut dates and sometimes the possibility of a supplementary cut.