http://http://dspace.unitus.it:80 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. 2013-05-23T09:52:07Z http://hdl.handle.net/2067/2085 Title: Stima probabilistica del tasso di espansione annua e del valore al 1990 della superficie forestale nella Regione Abruzzo Authors: Corona, Piermaria; Pompei, Enrico; Scarascia Mugnozza, Giuseppe Abstract: In Italy, reliable updated data on forest expansion on a national or regional scale are not available. The aim of this note is to present a probabilistic estimation approach based on land cover classification repeated on the same sample points for two successive occasions. The approach was experimented in the Abruzzo region (Central Italy), where the rate of forest expansion was assessed by multitemporal classification of permanent sample points on orthocorrected aerial photos. The forest area at the year 1990, a figure of high relevance for reporting under the Kyoto Protocol, was also assessed. The proposed procedure proved to be relatively easy to implement and able to provide precise estimates, given the adopted sampling intensity (the same of the Italian national forest inventory). It is stressed that statistical figures of forest areas on wide territories obtained by estimation approaches like the proposed one are scientifically more defensible than those traditionally based on the complete mapping, being more objectively repeatable. Description: L'articolo è disponibile sul sito dell'editore www.sisef.it 2004-12-31T23:00:00Z http://hdl.handle.net/2067/1627 Title: Structural patterns, growth processes, carbon stocks in an Italian network of old-growth beech forests Authors: Piovesan, Gianluca; Alessandrini, Alfredo; Baliva, Michele; Chiti, Tommaso; D'andrea, Ettore; De Cinti, Bruno; Di Filippo, Alfredo; Hermanin, Luigi; Lauteri, Marco; Scarascia Mugnozza, Giuseppe; Schirone, Bartolomeo; Ziaco, Emanuele; Matteucci, Giorgio Abstract: In the framework of the Project of National Interest (PRIN) “Climate change and forests - Dendroecological and ecophysiological responses, productivity and carbon balance on the Italian network of old-growth beech forests”, 9 old beech (Fagus sylvatica L.) forests were sampled in the eastern Alps and in the central Apennines to assess: i) the degree of ‘old-growthness’ on a structural and dendroecological basis; ii) the carbon (C) stocks in the different ecosystem compartments; iii) some ecophysiological traits using stable isotopes. Live and dead tree structure, soil features and C stocks were examined in some among the oldest and less disturbed beech forests in Italy. Furthermore, leaves, litter and wood cores were sampled for concurrent dendroecological, nutrient and stable isotope analysis, to study age structure, disturbance history and medium- and long-term response to climate and ecophysiological traits. In all sampled stands, values of basal area, volume and large trees density reached or exceeded control values reported for European and North American old-growth forests, while total amount of deadwood was generally low, except in two sites. Diameter distribution showed a remarkable differentiation from bimodal to ‘rotated-sigmoid’ curve. In accordance with structural analyses, disturbance chronologies revealed the importance of frequent low-to-moderate events in generating a fine-scale structure, confirming previous results on beech forests. Different degrees of ‘old-growthness’ were identified for Alpine and Apennine beech stands through the ‘structural-based approach’, which proved to be a valid tool for old-growth forests detection. Preliminary results on carbon stocks on a subset of sites indicate that these old-growth forests are relevant carbon reservoirs, with 192-268 MgC ha-1 of total biomass (67-73% aboveground; 27-33% belowground, 4 stands) and 7-21 MgC ha-1 of deadwood. In these stands, also forest floor (excluding deadwood) and soils are stores of relevant amount of carbon (5-9 MgC ha-1 litter layer, 4 stands; 168-420 MgC ha-1 mineral soil, 3 stands). Finally, carbon isotope discrimination (Δ) analysis, a proxy of wateruse efficiency, was applied on tree-ring cores from a subset of sites. The perspectives of this technique for a retrospective ecophysiological interpretation of climate-change impact on old-growth forests were described. Preliminary results obtained within this PRIN project indicate that the reported ecological indicators can be used to produce a description of forest structures and processes driving stand dynamics (‘structural-based approach’). Furthermore, the use of multiple sampling and research techniques and the integration of research groups with complementary expertise can foster deeper understanding of the ecology and dynamics of old-growth forests. Description: L'articolo è disponibile sul sito dell'editore http://www.aisf.it/ 2009-12-31T23:00:00Z http://hdl.handle.net/2067/2115 Title: Modelling natural forest expansion on a landscape level by multinomial logistic regression Authors: Corona, Piermaria; Calvani, Paolo; Scarascia Mugnozza, Giuseppe; Pompei, Enrico Abstract: Natural forest expansion is one of the most relevant landscape changes in many temperate countries. Although large areas are involved, relatively few studies have been carried out with the objective of unravelling the specific impact of the individual factors characterising the sites prone to such a process. The aim of this article is to present a research tool for assessing the factors characterising farmland sites prone to natural conversion from crop growing and pasture to forests and other wooded land (OWL), and for predicting the probability of such a land-use change. The methodological approach is based on multinomial logistic regression. As a case study, the approach was applied to land-use classification repeated on the same sites in a large area of central Italy on two successive occasions, spanning two decades, from the beginning of the 1980s up to 2002. Of all the factors assessed, landscape attributes were identified as a sufficient subset for quantitative prediction of change from farmland to OWL or to forest. The tested modelling approach is explicitly empirical and planning-oriented. From a quantitative point of view, the precision of the models may be only indicative for assessing land-use change probability for single observations, while it is appropriate for predicting mean probabilities at a landscape mapping level, where it is possible to sample a number of sites. At this level, the approach is a useful tool for simulating future landscape scenarios related to natural forest expansion. Description: L'articolo è disponibile sul sito dell'editore www.tandf.co.uk/journals/ 2007-12-31T23:00:00Z