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During the last millennia, all forests of the Italian Alps have been heavily affected by human land-use. Consequently, forest structures have been modified, and there are no old growth remains. In the last decades, however, many forests have been withdrawn from regular management, because wood production was unprofitable, and left to develop naturally. At the same time, in currently managed forests, silvicultural systems able to develop or maintain old-growth characteristics are being required. The aim of this paper was to assess the status and developmental dynamics of old-growth characteristics in mixed beech, silver fir, and Norway spruce montane forests of the eastern Italian Alps. We selected along a naturalness gradient (a) three old-growth forests in Bosnia and Montenegro (due to the lack of old-growth forests in the Italian Alps), (b) two forests withdrawn from regular management for at least 50 years, and (c) three currently managed forests. In each forest, we analysed 17 structural attributes, in order to assess their value as indicators of old-growth condition. Old-growth forests were characterized by significantly higher amounts of live and dead biomass, share of beech in the dominant and regeneration layers, and number of large trees. The diameter distribution was best described as a rotated sigmoid, differently from currently and formerly managed forest. We discuss the differences in old-growth characteristics across the management gradient and use our results to evaluate the effectiveness of retention prescriptions currently applied in the studied regions in maintaining or promoting old-growth structural attributes in managed forests. [ABSTRACT FROM AUTHOR]

Abstract: The role of deadwood on biodiversity conservation of forest ecosystems is widely recognised. Interest on deadwood has increased in the last years, and forest management policy regards deadwood as indicator of sustainable forest management. This study took place in mixed montane forests in Eastern Italian Alps. The objective was to determine how past forest management, topography and forest structure influenced coarse woody debris (CWD) accumulation. 124 sampling points were established in four forest reserves, where time since active management activities ranges from 12 to more than 50 years. A multivariate analysis was performed to investigate the connections among site, stand characteristics, and CWD. Coarse woody debris volume in the reserves was similar to other forests withdrawn from regular management in last decades in central Europe. However, CWD stocking was much lower than in old-growth montane mixed forest. Both site and stand characteristics determined CWD accumulation. Elevation, basal area of living trees and human impact emerged as the most important factors. These aspects are connected with the accretion (density-dependent mortality) and the depletion (harvesting, decay) of deadwood in the stand. In the next decades we expect an increase of deadwood stocking, due to density-dependent mortality and disturbances. [ABSTRACT FROM AUTHOR]

Abstract: Rapid glacier retreat often results in extensive areas of deglaciated terrain where primary successional processes occur. We studied biotic and abiotic factors underlying the invasion of larch (Larix decidua Mill.) on a glacier foreland and tested the hypothesis that the pattern of its establishment was controlled primarily by terrain age. The time span between deglaciation and establishment of larch and the importance of the position and shape of the glacier on the forest structure were studied over ∼150 years of glacial retreat. We related three data sets (forest structure, topography and spatial position) using ordination methods. Simple and partial Mantel tests and kriging interpolation were used to map and identify the key factors underlying the spatial patterns of larch establishment. The elapsed time between deglaciation and the germination of the larch trees was estimated between 14 and 34 years, with lower values found closer to the glacier terminus. Sparse and young stands developed near the glacier terminus and Mantel tests indicated significant correlations between spatial distance and ecological distance. The kriging interpolation showed strong agreement between tree age and the spatial pattern of the retreating glacier. The most influential factors in determining stand density and age were proximity to the glacier terminus and seed sources, as well as litter cover and elevation. The age of trees was strongly influenced by terrain age or time since deglaciation, but as succession progressed forest structure became more complex. [Copyright &y& Elsevier]

Abstract: It is frequently believed that a post-fire environment requires immediate actions in order to be restored. Salvage logging followed by plantation is a common post-fire restoration practice in many forests of the northwestern Italian Alps. The objectives of this study were to assess the impact of active and passive management techniques on the restoration of a burned area of the Aosta Valley and to determine which approach is the most suitable for enhancing Pinus sylvestris regeneration after stand replacing wildfires. The influence of five management options (no intervention; salvage logging; broadleaves plantation; Larix decidua plantation; P. sylvestris or Pseudotsuga menziesii plantation) and environmental variables on natural regeneration structure and composition was evaluated through direct gradient analysis. Pinus sylvestris and Populus tremula were the dominant tree species (40 and 29%, respectively) in the regeneration layer. Density, size, and structural diversity of natural regeneration were higher in the no intervention area. The proximity to forest edge was found to be the most important environmental variable. This study provided evidence that taking advantage of natural restoration processes may be a suitable alternative strategy to the active restoration practices adopted according to the Aosta Valley policy of post-fire management. [ABSTRACT FROM AUTHOR]