Variability in Silver Fir Growth in the Tuscan Apennine Alps in the 20th Century

Climate variables have shown that monthly mean temperature (MT) and monthly rainfall (MR) are non-stationary in the Tuscan Apennine Alps during the 20th century; similarity between trends in monthly climate variables varies irregularly through time at the seasonal and monthly scales, and site. High variability and anomalies in silver fir (Abies alba Mill.) growth have been observed in various regions of Europe and Italy. This scenario has suggested to investigate if tree-ring chronologies in silver fir vary among sites during the 20th century in the Tuscan Apennine Alps, if there are differences in tree-ring growth at upper and lower elevation within silver fir forests, and if there are anomalous or unexpected growth patterns in tree-ring chronologies of silver fir. Results shows that similarity in Residual Tree-rings series (RTRs) varies highly, frequently, and irregularly during the 20th century among sites and, to a lesser extent, within silver fir forest sites in the Tuscan Apennine Alps. Unexpected patterns of growth occur in silver fir in the last decades of the 20th century; and similarity between RTRs of the silver fir study stands tends to reduce with increasing distance among sites. Results recommend monitoring and extend this and similar investigations in the view of the climate change scenarios recently provided by research where the impacts on the viability and possibly shift of silver fir populations – and other species - in their southern European range rise serious concerns.