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Norway spruce is one of the most important conifer tree species in Europe, paramount for timber provision, habitat, recreation, and protection of mountain roads and settlements from natural hazards. Although natural Norway spruce forests exhibit diverse structures, even-aged stands can arise after disturbance or as the result of common silvicultural practice, including off-site afforestation. Many even-aged Norway spruce forests face issues such as senescence, insufficient regeneration, mechanical stability, sensitivity to biotic disturbances, and restoration. We propose the use of Density Management Diagrams (DMD), stand-scale graphical models designed to project growth and yield of even-aged forests, as a heuristic tool for assessing the structure and development of even-aged Norway spruce stands. DMDs are predicated on basic tree allometry and the assumption that self-thinning occurs predictably in forest stands. We designed a DMD for Norway spruce in temperate Europe based on wide-ranging forest inventory data. Quantitative relationships between tree- and stand-level variables that describe resistance to selected natural disturbances were superimposed on the DMD. These susceptibility zones were used to demonstrate assessment and possible management actions related to, for example, windfirmness and effectiveness of the protective function against rockfall or avalanches. The Norway spruce DMD provides forest managers and silviculturists a simple, easy-to-use, tool for evaluating stand dynamics and scheduling needed density management actions. [ABSTRACT FROM AUTHOR]

Scots pine ( Pinus sylvestris L.) forests of many inner Alpine valleys have recently displayed a quick loss of vitality. A decline disease has been suggested as the cause, with drought as the main predisposing factor and the additional contribution of biotic agents inciting tree dieback. This study is focused on Valle d'Aosta, a dry, inner-Alpine region in NW Italy. We inferred vitality changes between years 2000 and 2007 by computing reductions in enhanced vegetation index (EVI). Image differencing was carried out on pre-processed Moderate Resolution Imaging Spectroradiometer (MODIS) imagery taken in late springtime and validated against ancillary ground truth. We: (1) tested whether EVI reductions in Scots pine forests were significantly higher than those of a control species and of a wetter region for the same species, (2) analyzed decline incidence as a function of site and topographic variables, and (3) assessed the relative influence of site and stand structure on decline probability by means of path analysis. Mean EVI in the study area increased due to an early onset of the 2007 growing season. Nevertheless, the incidence of decline was 6.3% and significantly greater for Scots pine than the control species and site. Low-elevation, northerly exposed sites exhibited the highest incidence of decline. Path analysis suggested that the most important determinants of decline probability were slope, solar radiation, and stand sparseness. [ABSTRACT FROM AUTHOR]

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]

Scaling is widely recognized as a central issue in ecology. The associated cross-scale interactions and process transmutations make scaling (i.e. a change in spatial or temporal grain and extent) an important issue in understanding ecosystem structure and functioning. Moreover, current concepts of ecosystem stewardship, such as sustainability and resilience, are inherently scale-dependent. The importance of scale and scaling in the context of forest management is likely to further increase in the future because of the growing relevance of ecosystem services beyond timber production. As a result, a consideration of processes both below (e.g. leaf-level carbon uptake in the context of climate change mitigation) and above (e.g. managing for biodiversity conservation at the landscape scale) the traditional focus on the stand level is required in forest ecosystem management. Furthermore, climate change will affect a variety of ecosystem processes across scales, ranging from photosynthesis (tree organs) to disturbance regimes (landscape scale). Assessing potential climate change impacts on ecosystem services thus requires a multi-scale perspective. However, scaling issues have received comparatively little attention in the forest management community to date. Our objectives here are thus first, to synthesize scaling issues relevant to forest management and second, to elucidate ways of dealing with complex scaling problems by highlighting examples of how they can be addressed with ecosystem models. We have focused on three current management issues of particular importance in European forestry: (1) climate change mitigation through carbon sequestration, (2) multi-functional stand management for biodiversity and non-timber goods and services and (3) improving the resilience to natural disturbances. We conclude that taking into account the full spatiotemporal heterogeneity and dynamics of forest ecosystems in management decision-making is likely to make management more robust to increasing environmental and societal pressures. Models can aid this process through explicitly accounting for system dynamics and changing conditions, operationally addressing the complexity of cross-scale interactions and emerging properties. Our synthesis indicates that increased attention to scaling issues can help forest managers to integrate traditional management objectives with emerging concerns for ecosystem services and therefore deserves more attention in forestry. [ABSTRACT FROM AUTHOR]