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Effetti dei metodi e dei sistemi di esbosco sulla quantità e sulla distribuzione dei residui forestali a seguito di operazioni di salvage logging: un'analisi multi-scala in foreste montane
No full textA key function of forests is the ability to capture and store carbon, however the impact of climate change and its induced events not only jeopardizes their ecological integrity but also affects their multifunctionality where they serve not only as production but also, mainly, as regulation, protection and recreation. Mountain forests, often characterized by unique species and ecosystems, are highly sensitive to climate variability and are amongst the most impacted due to the increasing incidence of such events. Salvage logging, a method employed to recover timber from forests damaged by disturbances such as storms, fires, or pests, plays a crucial role in mitigating economic losses and reducing future risks in mountain forests. However, the methods and systems used during these operations significantly influence the quantity and distribution of harvesting residues—non-merchantable tree parts such as branches, tops, and foliage left behind. Residue management is vital in maintaining forest health, where they contribute by acting as nutrient reservoir, habitat for animal species, shelter for regeneration, and contrast soil compaction but where excessive residue accumulation can increase fire hazards, hinder forest regeneration, and alter nutrient cycling. This thesis aims to explore how different harvesting methods and systems affect the amount and spatial patterns of these residues in mountain forests, utilizing a multi-scale analysis to assess impacts across various terrains and forest conditions.
A state-of-the-art about management practices and treatments at global level was drawn to give a general and complete overview of impacts and effects of such management strategies on four different investigated areas: biodiversity, soil-nutrients, plantations and energy, and fire. Moreover, a focus on permitted practices was done on the Italian regulatory framework. Furthermore, the harvesting systems and methods used for salvage logging or comparable operations (i.e., where there is the complete removal of timber and woody material) were inspected in considering their impact on residues spatial and quantity distribution. The investigation was conducted at different levels by considering manual estimations methods, drone-based methods and satellite-based methods
Effetti dei sistemi di utilizzazione e modalità di esbosco : studio preliminare sul rilascio di biomassa ed efficienza del cantiere forestale
Full text linkEffetti dei sistemi di utilizzazione e modalit{\`{a}} di esbosco: studio preliminare sul rilascio di biomassa ed efficienza del cantiere forestale Alberto Cadei, Alberto Udali, Mihail Bacescu, Stefano Grigolato Nel contesto alpino, i sistemi di utilizzazione forestale si distinguono in processi di lavoro semimeccanizzati e completamente meccanizzati. In entrambi i casi, i sistemi di lavoro possono essere a pianta intera e legno corto. A seguito della tempesta Vaia, per garantire il recupero di ingenti volumi di legname danneggiato in superfici anche estese, si {\`{e}} fatto ampio ricorso a sistemi di utilizzazione completamente meccanizzati o sistemi semi-meccanizzati con l'impiego di macchine e attrezzature avanzate. I principali sistemi di utilizzazione impiegati sono stati quello del sistema con esbosco a legno corto completamente meccanizzato con l'impiego di harvester e forwarder e quello con esbosco con albero intero o parzialmente intero con gru cavo e l'allestimento del legname a bordo strada tramite processore. Questi due sistemi, dunque, possono avere un diverso effetto sulla quantit{\`{a}} di biomassa rilasciata in bosco a seguito dell'abbatimento, sramatura, allestimento ed esbosco: nel caso di harvester e forwarder, l'intera biomassa, che comprende ramaglie e parte del cimale, {\`{e}} rilasciata in bosco, mentre nel caso dell'utilizzo di gru a cavo, ramaglia e cimali vengono accumulati a bordo strada all'imposto in cui avviene l'allestimento del legname. Inoltre, l'attuale contesto operativo nelle Alpi orientali ha evidenziato il vantaggio, in termini di sicurezza per gli operatori, nell'impiego di sistemi di utilizzazione a completa meccanizzazione e l'impiego di macchine e attrezzature avanzante anche nel sistema di lavoro a pianta intera. Per meglio comprendere l'effetto della meccanizzazione in questi contesti, occorre per{\`{o}} anche valutare l'efficienza economica ed ecologica dei diversi sistemi di utilizzazione considerati, sia in termini di produttivit{\`{a}} che in termini di consumi di carburante per unit{\`{a}} di legname lavorato In questo contesto, il presente lavoro si pone due obbiettivi: a) valutare se l'adozione di un sistema di lavoro (pianta intera e legno corto) influenza in modo significativo i quantitativi di biomassa forestale presenti in bosco; b) valutare l'efficienza economica ed ecologica dei diversi sistemi di utilizzazioni e di lavoro considerati. I due obbiettivi sono stati verificati analizzando tre tipologie di cantieri: sistema di utilizzazione completamente meccanizzato a legno corto (cantiere harvester - forwarder) , sistema di utilizzazione semi-meccanizzato a pianta intera (cantiere gru a cavo - processore) e cantiere tradizionale semi-meccanizzato di tipo terrestre a legno corto (allestimento in bosco ed esbosco con trattore e verricello). La quantificazione e valutazione della biomassa rilasciata in seguito all'utilizzazione {\`{e}} avvenuta tramite transetti di campionamento. L'analisi della produttivit{\`{a}} e dei consumi {\`{e}} avvenuta utilizzando i dati di dettaglio forniti dalle macchine utilizzate sia in termini di consumi che di produttivit{\`{a}} (cantiere harvester e forwarder), o tramite cubatura manuale del legame esboscato (cantiere gru a cavo e trattore e verricello)
Can SAR Data Predict Harvesting Residues Mass?
Full text linkThe increasing demand for large-scale, high-frequency environmental monitoring has driven the adoption of satellite-based technologies for effective forest management, especially in the context of climate change. This study explores the potential of SAR for estimating the mass of harvesting residues, a significant component of forest ecosystems that impacts nutrient cycling, fire risk, and bioenergy production. The research hypothesizes that while the spatial distribution of residues remains stable, changes in moisture content—reflected in variations in the dielectric properties of the woody material—can be detected through SAR techniques. Two models, generalized linear model (GLM) and random forest (RF), were used to predict the mass of residues using interfer-ometric variables (phase, amplitude and coherence) as well as the backscatter signal from several acquisition pairs. The models provided encouraging results (R2 of 0.48 for GLM and 0.13 for RF), with acceptable bias and RMSE. We concluded that SAR data are feasible to predict the mass of harvesting residues and the findings could lead to improved monitoring and management of forest residues, contributing to sustainable forestry practices and enhanced bioenergy resource utilization
Opportunity to integrate machine management data, soil, terrain and climatic variables to estimate tree harvester and forwarder performance
Full text linkAssessing Forest Type and Tree Species Classification Using Sentinel-1 C-Band SAR Data in Southern Sweden
Full text linkThe multitemporal acquisition of images from the Sentinel-1 satellites allows continuous monitoring of a forest. This study focuses on the use of multitemporal C-band synthetic aperture radar (SAR) data to assess the results for forest type (FTY), between coniferous and deciduous forest, and tree species (SPP) classification. We also investigated the temporal stability through the use of backscatter from multiple seasons and years of acquisition. SAR acquisitions were pre-processed, histogram-matched, smoothed, and temperature-corrected. The normalized average backscatter was extracted for interpreted plots and used to train Random Forest models. The classification results were then validated with field plots. A principal component analysis was tested to reduce the dimensionality of the explanatory variables, which generally improved the results. Overall, the FTY classifications were promising, with higher accuracies (OA of 0.94 and K = 0.86) than the SPP classification (OA of 0.66 and K = 0.54). The use of merely winter images (OA = 0.89) reached, on average, results that were almost as good as those using of images from the entire year. The use of images from a single winter season reached a similar result (OA = 0.87). We conclude that multiple Sentinel-1 images acquired in winter conditions are feasible to classify forest types in a hemi-boreal Swedish forest
Digging up into windstorms aftermath: understanding the effect of harvesting systems on salvage logging wood residues spatial distribution
Full text linkExtreme disturbance events, such as climate change-driven ones, have increased their frequency, upsetting the ordinary management of forests, and impacting large areas with severe damage. As a consequence, when productive forests are hit, salvage logging operations represent the common way to recover part of the economic loose. However, salvage logging can lead to negative impacts in terms of soil erosion as well in terms of variation of soil carbon stock and nutrients. Commonly, in the European Alps, salvage logging operations in largely damaged forest areas can be referred generally to as two harvesting systems: i) Cut-to-Length (CTL) and ii) Full-Tree (FT) extraction systems.
The application of the two harvesting systems can have a different effect on the type and quantity of logging residues and deadwood left on the forest ground, which in the short-medium term it can be reflected in terms of quantity and distribution of organic carbon and nutrients in the soil.
To evaluate and gather more detailed information on the effects of forest operations, a valuable option is to rely on the use of precision forestry approaches, such as the use of remote sensing (RS) and Artificial Intelligence applications, for example, machine learning (ML). In the realm of forest operations, ML techniques and algorithms are the most used and can be fed with data directly extracted from the machines operating live on sites, and also with data retrieved through RS. Drone-borne data, for example, is now becoming the most used for its large potential and applicability, providing both large coverage and a high level of detail oversampled areas.
The aim of this study is thus comparing two salvage logging areas and find any difference in terms of logging residue type, quantity, and spatial distribution according to the used harvesting system.
Drone flights over two logging areas in the northeastern Alps to retrieve logging residues data were performed in 2022, the sites were windthrown in 2018 and harvested in 2021. A random forest model was built using RGB bands derived from the drone images, textural variables, and information from the surface model to classify elements in a clear-felled site. After the classification and noise removing operations, residues mass per hectare and distribution were estimated.
Preliminary results will show the strengths and weaknesses of the method adopted in assessing the type of residues and their spatial distribution. Moreover, this application will highlight the different impacts of the two systems adopted in salvage logging operations with respect to residue type and quantity left on site
Economic Impacts of Forest Storms—Taking Stock of After-Vaia Situation of Local Roundwood Markets in Northeastern Italy
Full text linkLarge timber availability after storms can lead to a drop in timber prices that can impact local markets. The Vaia storm, which occurred in Northeastern Italy at the end of October 2018, felled large volumes of timber, spruce in particular. To estimate the loss in volume and value connected to Vaia, data of roundwood sales from four local markets (Province of Trento, Province of Bol-zano, Veneto Region and Friuli Venezia Giulia Region) were collected before and after Vaia, as well as reports on the status of salvage operations. The results confirm that Vaia had a strong impact on Northeastern Italy. A large area of the forest was hit and massive volumes of wood were affected. The analysis on prices showed a negative trend in the post Vaia period due to an increase in volume per sale, especially for stumpage sales. It also highlighted the difficulties of storing the salvaged wood and the consequent fast saturation of the market. Although it was not possible to assess long-term effects on the four local markets, the presence and use of local e-commerce platforms proved useful in making roundwood sales more organized and efficient
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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