Stand history and its consequences for the present and future dynamic in two silver fir (Abies alba Mill.) stands in the high Pesio Valley (Piedmont, Italy)

Abstract

Two silver fir (Abies alba Mill.) forest stands have been identified on unmanaged parts of previously managed forests in the "Alta Valle Pesio e Tanaro" Regional Park (Piedmont, Italy) in order to study their origin, past forest dynamic and disturbance history. The historical development and the successional history of these stands were investigated in two plots of 2000 m2 by means of the following techniques: size and age structure analysis, abrupt growth changes analysis, establishment of pioneer species and of early-seral shade-intolerant species, historical data of logging. The stands investigated are relatively young; in the past 70 years some periods of heavy logging have been identified. Intense cutting has caused the establishment of an abundant regeneration of shade intolerant early-seral broadleaves species. The peak recruitment period of the broadleaves occurred around 1940 in plot 1 and around 1975 in plot 2. The current structures and composition of the forest are therefore the result of anthropogenic activity, indeed, the presence of pure silver fir stands in the past were the result of human intervention. The silver fir will share future dominance with several broadleaves species such as the beech (Fagus sylvatica L.) and the sycamore (Acer pseudoplatanus L.) although the exact successional status of these stands is unresolved.