We investigated climatic trends in two contrasting
locations in Europe at a regional level and at two specific sites,
and we analysed how these trends are associated with the dry
matter yield (DMY) of agriculturally improved grasslands.
Trends of different meteorological variables were evaluated
for Wielkopolska province, central Poland (1985-2014) and
Troms county, northern Norway (1989-2015), as well as for
two research stations located in these regions. Significant
trends of increased mean air temperatures annually, and in
April, June, July, August and November were identified both
at the regional and site levels in Wielkopolska. In addition,
growing degree days were increasing in Wielkopolska. In
Troms, the common trends for the region and site studied
were increase in mean air temperature in May and decrease
in January. Grassland DMY was subsequently regressed
against those meteorological variables for which significant
trends were detected. In the Wielkopolska region, yields were
negatively associated with the increase in air temperature
in June, August, and the annual air temperature. The last
relationship was also detected at the site level. We did not
find any significant effects of climate trends on grassland
DMY in the Norwegian study site or region.
