1,721,302 research outputs found
A Sentinel-2 derived dataset of forest disturbances occurred in Italy between 2017 and 2020
Full text linkForests absorb 30% of human emissions associated with fossil fuel burning. For this reason, forest disturbances monitoring is needed for assessing greenhouse gas balance. However, in several countries, the information regarding the spatio-temporal distribution of forest disturbances is missing. Remote sensing data and the new Sentinel-2 satellite missions, in particular, represent a game-changer in this topic. Here we provide a spatially explicit dataset (10-meters resolution) of Italian forest disturbances and magnitude from 2017 to 2020 constructed using Sentinel-2 level-1C imagery and exploiting the Google Earth Engine GEE implementation of the 3I3D algorithm. For each year between 2017 and 2020, we provide three datasets: (i) a magnitude of the change map (between 0 and 255), (ii) a categorical map of forest disturbances, and (iii) a categorical map obtained by stratification of the previous maps that can be used to estimate the areas of several different forest disturbances. The data we provide represent the state-of-the-art for Mediterranean ecosystems in terms of omission and commission errors, they support greenhouse gas balance, forest sustainability assessment, and decision-makers forest managing, they help forest companies to monitor forest harvestings activity over space and time, and, supported by reference data, can be used to obtain the national estimates of forest harvestings and disturbances that Italy is called upon to provide
16. Ottimizzazione del campione dendrometrico
No full textNell'ambito della redazione del Piano di Gestione della Riserva Naturale Statale biogenetica di Vallombrosa è stata condotta una sperimentazione volta a ottimizzare il tempo di rilievo e la dimensione del campione per il rilievo quantitativo dendrometrico. i risultati evidenziano che la migliore dimensione delle aree di saggio, di forma circolare, verificata sul CV dell'area basimetrica e nell'ottica di minimizzare i tempi di rilievo è pari a 1257 metri quadrati, ovvero un raggio di 20 metri lineari
Factors affecting the quantity and type of tree-related microhabitats in mediterranean mountain forests of high nature value
Full text linkTree-related microhabitats (hereafter TreMs) are structures occurring on trees, such as rot holes, cavities, large nests, mould, fruiting bodies and mycelia of decomposer fungi. TreMs have been widely recognized as important substrates and structures useful for biodiversity conservation in forest ecosystems, and they can be used as indicators for describing and monitoring forest naturalness. However, most studies on the occurrence of TreMs have been mainly done in forest ecosystems of Central Europe, while less research has been conducted in Mediterranean mountain forests. In this study, we investigated the diversity and abundance of 23 types of TreMs on living trees and on deadwood in seven Mediterranean mountains unmanaged forests located in the Apennines (Italy). The abundance of TreMs was evaluated by counting the number of TreMs per tree, while the diversity of TreMs was evaluated by means of the Shannon-Wiener index. We focused on the relationships between diversity and abundance of TreMs, and tree size (e.g., diameter, height, volume), and the time since the last harvest. Among the investigated stands, 2612 living trees, 457 standing dead trees and snags, and 1247 lying deadwood pieces were analysed. For living trees, a generalized linear mixed model was applied to test the effect of several variables on the abundance of TreMs per tree. Diameter at breast height (DBH) of tree stems influenced the abundance and diversity of TreMs. The time since the last harvest also significantly affected the probability that TreMs could be formed in a long-term perspective. The interaction of the predictors “DBH2” and “Years since the last harvest” generated a better model than the one in which the two variables were kept separate. Indeed, these two factors together would better represent the transition of a previously managed forest to a more natural state over time. This study might provide useful information to land managers committed to forestry practices towards sustainable management and biodiversity conservation, especially referring to survey and inventory of forests of high nature value
Quantifying the rate of change in landscape diversity across hierarchical classification schemes.
No full textApplicazioni di probabilità a priori su basi ecologiche a supporto della classificazione di immagini Landsat a fini forestali
No full textProcedura di valutazione degli interventi di rimboschimento come strumenti di composizione dell’ecotessuto paesistico
No full textModel-assisted estimation of forest attributes exploiting remote sensing information to handle spatial under-coverage
No full textModel-assisted estimation of forest wood volume is approached exploiting the wall-to-wall information available from satellite data and partial information achieved from airborne laser scanning (ALS) covering a portion of the survey area. If the portion covered by ALS is selected by a probabilistic sampling scheme, two-phase estimators are considered in which the two sources of information are exploited by means of linear and non-linear models. If the portion covered by ALS is fixed because purposively selected, the two sources of information are exploited by the double-calibration estimator. The performance of the proposed strategies is checked by a simulation study from two study areas in Southern and Northern Italy
Confronto tra indicatori di diversità floristica e strutturale nelle foreste europee.
Full text linkEvidence-based policies are necessary to support the role of forests in the conservation of biodiversity and provisioning of ecosystem services. Assessing forest resources and their trends over time is required by many international agreements, and is a key step in developing policy strategies. In the context of National Forest Inventories, measures of tree species composition and structure are considered as possible biodiversity indices, despite ground vegetation usually having greater species richness than other forest strata. This study is aimed at evaluating relationships and connections between the overstory and understory by considering both stand structure and diversity indices, through a network analysis in which the system takes the form of a network or "graph". We used tree-related and ground vegetation data from 2789 plots collected as part of the BioSoil project through the ICP Forests Level I network and stored in the LI-BioDiv database. Additional information levels such as biogeographical region, forest management type and European Forest Type were also considered. The relationships among the structural and diversity measures showed few and weak correlations between overstory and understory diversity over the additional information levels. We demonstrated that at European level the overstory and understory indices are complementary, and they explain forest diversity components. Based on these results, overstory diversity cannot be considered as a proxy for the diversity of the entire forest plant community
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