TREE-RING RESPONSE OF PINUS ELDREICHII TO CLIMATE AND ANTHROPOGENIC ACTIVITY IN THE NATIONAL PARK OF POLLINO (BASILICATA, SOUTHERN ITALY).

Pinus eldreichii is widespread in the Balkan Peninsula and in its western area, in southern Italy, is present as a post-glacial relict species. The main Italian populations are located at the tree-line in the National Park of Pollino. For many centuries, grazing and logging endangered the survival of pine populations at the tree-line, so that during 1990s the National Park was founded and anthropogenic activities were partly forbidden and partly prescribed to preserve P. eldreichii. We used tree ring-width patterns as indicators of environmental changes and to interpret the impact of anthropogenic activities (deduced from historical records) on P. eldreichii stands. An increase in ring width since 1980s to date was detected. Possible causes for this observed trend include increases in nitrogen deposition, atmospheric CO2 concentration and air temperature, or a decrease in anthropogenic pressure. A positive effect of thinning, logging or nitrogen fertilization on tree-ring width can be excluded, because P. eldreichii trees are scattered and atmospheric nitrogen deposition is scarce on Monte Pollino. We also found that ring-width is not strongly influenced by monthly precipitation and mean monthly temperatures, suggesting that at this site tree rings reflect land-use changes caused by socio-economic reasons than by climatic changes.