Papers by roberta berretti
... Forest area statistics. Web site FAO Forestry - part of World Agricultural Information Centre... more ... Forest area statistics. Web site FAO Forestry - part of World Agricultural Information Centre. ... 52. Szwagrzyk J, Szewczyk J (2001). Tree mortality and effects of release from competition in an old-growth Fagus-Abies-Picea stand. Journal of Vegetation Science 12: 621-626. ...
Natural Hazards and Earth System Sciences, Mar 23, 2018
Modeling and assessing the factors that drive forest fire ignitions is critical for fire preventi... more Modeling and assessing the factors that drive forest fire ignitions is critical for fire prevention and sustainable ecosystem management. In southern Europe, the anthropogenic component of wildland fire ignitions is especially relevant. In the Alps, however, the role of fire as a component of disturbance regimes in forest and grassland ecosystems is poorly known. The aim of this work is to model the probability of fire ignition for an Alpine region in Italy using a regional wildfire archive (1995-2009) and MaxEnt modeling. We analyzed separately (i) winter forest fires, (ii) winter fires on grasslands and fallow land, and (iii) summer fires. Predictors were related to morphology, climate, and land use; distance from infrastructures, number of farms, and number of grazing animals were used as proxies for the anthropogenic component. Collinearity among predictors was reduced by a principal component analysis. Regarding ignitions, 30 % occurred in agricultural areas and 24 % in forests. Ignitions peaked in the late winter-early spring. Negligence from agrosilvicultural activities was the main cause of ignition (64 %); lightning accounted for 9 % of causes across the study time frame, but increased from 6 to 10 % between the first and second period of analysis. Models for all groups of fire had a high goodness of fit (AUC 0.90-0.95). Temperature was proportional to the probability of ignition, and precipitation was inversely proportional. Proximity from infrastructures had an effect only on winter fires, while the density of grazing animals had a remarkably different effect on summer (positive correlation) and winter (negative) fires. Implications are discussed regarding climate change, fire regime changes, and silvicultural prevention. Such a spatially explicit approach allows us to carry out spatially targeted fire management strategies and may assist in developing better fire management plans.
Italian Journal of Forest and Mountain Environments, 2010
RENZO MOTTA (*) (°)-ROBERTA BERRETTI (*)-SIMONE BORCHI (**) ALFREDO BRESCIANI (**)-MATTEO GARBARI... more RENZO MOTTA (*) (°)-ROBERTA BERRETTI (*)-SIMONE BORCHI (**) ALFREDO BRESCIANI (**)-MATTEO GARBARINO (*)-DIEGO TRUCCHI (*)
Annals of forest science, 2010
• We studied structural characteristics, amount and quality of coarse woody debris (CWD), intensi... more • We studied structural characteristics, amount and quality of coarse woody debris (CWD), intensity of competition and mortality in two subalpine Norway spruce stands withdrawn from regular management. The stands, that we measured twice (in 1993 and 2005), have similar age and structure, but a different time has elapsed since the last silvicultural treatments (respectively 22 and about 55 y). • The main purposes were to analyze the current stage of development as compared to the old-growth one and to highlight the legacies of past management. • Although relatively old, the first plot (Valbona 1) was at the end of the pole stage. CWD was low in volume and was mainly of man-made origin (stumps). A recent thinning from below has reduced density-dependent competition and delayed the development of old-growth characteristics. The second plot (Valbona 2a) was at the beginning of the transition stage, with density-dependent and allogenic mortality both active at the same time. CWD volume was higher in plot Valbona 2a than in Valbona 1, but neither was comparable yet to the reference old-growth sites from Central Europe, both in quantity and in quality (e.g., decay rate continuity). • The effects of the past management were: (1) reducing the quality and quantity of the CWD, (2) alleviating competition, (3) increasing resistance to minor disturbances and, as a consequence, (4) delaying the development processes. • In mature or overmature subalpine Norway spruce stands withdrawn from regular management many decades are necessary to develop old-growth characteristics and a longer period of time is necessary to reach a true old-growth stage.
European Journal of Forest Research, Jul 18, 2014
During the last millennia, all forests of the Italian Alps have been heavily affected by human la... more 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 1,*
Italian Journal of Forest and Mountain Environments, 2007
ANTONIO NOSENZO (*)-ROBERTA BERRETTI (**)-FABIO MELONI (***) ANALISI DELLA BIOMASSA E DEGLI ASSOR... more ANTONIO NOSENZO (*)-ROBERTA BERRETTI (**)-FABIO MELONI (***) ANALISI DELLA BIOMASSA E DEGLI ASSORTIMENTI LEGNOSI RITRAIBILI DA BOSCHI CEDUI DI FAGGIO DEL PIEMONTE (1) Attualmente i boschi cedui di faggio (Fagus sylvatica L.) nella Regione Piemonte coprono circa 100.000 ettari (90% delle formazioni di faggio). Questi popolamenti spesso risultano aver oltrepassato i turni consuetudinari con la conseguenza che anche gli assortimenti legnosi ottenibili non siano più quelli prodotti in passato. Il presente lavoro ha avuto come obiettivo quello di mettere a punto una metodologia per determinarne la produzione ritraibile in termini di legname da opera. Si sono individuate 20 zone distribuite sul territorio piemontese nelle quali si è proceduto ai rilievi dendrometrici ordinari. In due popolamenti si è eseguita un'analisi di dettaglio della qualità dei fusti. Dopo una prima valutazione, durante la quale sono state individuate le piante con difetti tali da non poterne consentire la lavorabilità, si è proceduto alla misurazione di quelle ritenute di «qualità». Dall'elaborazione dei dati e sulla base della classificazione commerciale degli assortimenti si è pervenuti alla definizione della produzione in assortimenti. La metodologia sperimentata mira alla valorizzazione della produzione, in quanto permette di individuare una percentuale di prodotti di migliore qualità rispetto ai tradizionali assortimenti ritraibili. È stato possibile infatti individuare sino al 20% di assortimenti di maggior pregio. Inoltre è da rimarcare che i dati raccolti si riferiscono allo stato attuale derivante dalla mancanza di cure colturali e di indirizzi selvicolturali. La definizione delle caratteristiche qualitative degli assortimenti risulta utile a fornire indicazioni circa gli obbiettivi da conseguire con la gestione selvicolturale dei popolamenti.
Plant Biosystems, Aug 9, 2013
In dry, inner-alpine valleys, regeneration of Scots pine after large, high-severity fires is limi... more In dry, inner-alpine valleys, regeneration of Scots pine after large, high-severity fires is limited by seed dispersal distance. When dispersal limitations are relaxed (small fires), colonization dynamics of Scots pine remain unclear. Our aims were: (1) to assess the regeneration niche of Scots pine seedlings following small fires in a dry, inner-alpine valley, and (2) to measure the influence of competition, drought, fertility, and soil pH on pine colonization. We sampled pine seedlings in six high-severity fires (1962-2006), where distance from the unburned edge was <60 m. We modeled seedling density as a function of topography and soil cover by means of Generalized Linear Models (GLM). Ellenberg indicator values (EIV) for light, moisture, soil pH, and fertility were computed from vegetation sampling at each plot, and used as additional predictors of seedling density. Pine colonization was initially slow due to drought, and peaked 16 years after fire. The inclusion of EIV provided +31% of explained deviance in models of seedling density. Herb cover and soil moisture were the most important predictors. Scots pine regenerates successfully following small, high-severity fires, albeit slowly due to unfavorable water balance. Hence, restoration by artificial regeneration may not be necessary when seed dispersal is ensured.
Forest Ecology and Management, Sep 1, 2010
The role of deadwood on biodiversity conservation of forest ecosystems is widely recognised. Inte... more 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 influence deadwood accumulation. 124 sampling points were established in four Forest Reserves, where time of nonintervention ranges from 12 to more than 50 years. A multivariate analysis was performed to investigate the connections between forest stand characteristics and deadwood. Coarse woody debris (CWD) volume in the reserves was similar to other recently-unmanaged forests in central Europe. Both stand characteristics and topographic factors determined CWD distribution. Basal area of living trees and human impact emerged as the most important factors. These aspects are connected with the input (density-dependent mortality) and the output (harvesting) of deadwood in the stand. In the next decades we expect an increase of deadwood, due to density-dependent mortality and disturbances. However, many decades in absence of human interventions are probably required to reach amount of deadwood similar to those in old-growth forests.
Italian Journal of Forest and Mountain Environments, Dec 19, 2007
ANTONIO NOSENZO (*)-ROBERTA BERRETTI (**)-FABIO MELONI (***) ANALISI DELLA BIOMASSA E DEGLI ASSOR... more ANTONIO NOSENZO (*)-ROBERTA BERRETTI (**)-FABIO MELONI (***) ANALISI DELLA BIOMASSA E DEGLI ASSORTIMENTI LEGNOSI RITRAIBILI DA BOSCHI CEDUI DI FAGGIO DEL PIEMONTE (1) Attualmente i boschi cedui di faggio (Fagus sylvatica L.) nella Regione Piemonte coprono circa 100.000 ettari (90% delle formazioni di faggio). Questi popolamenti spesso risultano aver oltrepassato i turni consuetudinari con la conseguenza che anche gli assortimenti legnosi ottenibili non siano più quelli prodotti in passato. Il presente lavoro ha avuto come obiettivo quello di mettere a punto una metodologia per determinarne la produzione ritraibile in termini di legname da opera. Si sono individuate 20 zone distribuite sul territorio piemontese nelle quali si è proceduto ai rilievi dendrometrici ordinari. In due popolamenti si è eseguita un'analisi di dettaglio della qualità dei fusti. Dopo una prima valutazione, durante la quale sono state individuate le piante con difetti tali da non poterne consentire la lavorabilità, si è proceduto alla misurazione di quelle ritenute di «qualità». Dall'elaborazione dei dati e sulla base della classificazione commerciale degli assortimenti si è pervenuti alla definizione della produzione in assortimenti. La metodologia sperimentata mira alla valorizzazione della produzione, in quanto permette di individuare una percentuale di prodotti di migliore qualità rispetto ai tradizionali assortimenti ritraibili. È stato possibile infatti individuare sino al 20% di assortimenti di maggior pregio. Inoltre è da rimarcare che i dati raccolti si riferiscono allo stato attuale derivante dalla mancanza di cure colturali e di indirizzi selvicolturali. La definizione delle caratteristiche qualitative degli assortimenti risulta utile a fornire indicazioni circa gli obbiettivi da conseguire con la gestione selvicolturale dei popolamenti.
Forest Ecology and Management, Apr 1, 2019
Uploads
Papers by roberta berretti
the snowpack. Techniques applied and economic evaluation in a direct protection forest of Piedmont. We describe
silvicultural measures to enhance the mass flow protection
service played by a larch-stone pine forest in Valle di Susa
(Italy). We illustrate stand structure and stability, and issues
due to snow gliding. We respond to this issue with the construction of temporary snow retention structures in order to stabilise the snowpack. We describe two types of structures
and the technique for their construction, and analyze the
cost-benefit tradeoff of the intervention.