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Pubblicazioni Scientifiche
Filtri di ricerca 8 risultati
Pubblicazioni per anno
Wall-to-Wall Mapping of Forest Biomass and Wood Volume Increment in Italy
Giannetti
,
Francesca
,
Chirici
,
Gherardo
,
Vangi
,
Elia
,
Corona
,
P.
,
Maselli
,
Fabio
,
Chiesi
,
Marta
,
D'Amico
,
Giovanni
,
Puletti
,
Nicola
Mostra abstract
Several political initiatives aim to achieve net-zero emissions by the middle of the twenty-first century. In this context, forests are crucial as a carbon sink to store unavoidable emissions. Assessing the carbon sequestration potential of forest ecosystems is pivotal to the availability of accurate forest variable estimates for supporting international reporting and appropriate forest management strategies. Spatially explicit estimates are even more important for Mediterranean countries such as Italy, where the capacity of forests to act as sinks is decreasing due to climate change. This study aimed to develop a spatial approach to obtain high-resolution maps of Italian forest above-ground biomass (ITA-BIO) and current annual volume increment (ITA-CAI), based on remotely sensed and meteorological data. The ITA-BIO estimates were compared with those obtained with two available biomass maps developed in the framework of two international projects (i.e., the Joint Research Center and the European Space Agency biomass maps, namely, JRC-BIO and ESA-BIO). The estimates from ITA-BIO, JRC-BIO, ESA-BIO, and ITA-CAI were compared with the 2nd Italian NFI (INFC) official estimates at regional level (NUT2). The estimates from ITA-BIO are in good agreement with the INFC estimates (R<sup>2</sup> = 0.95, mean difference = 3.8 t ha<sup>−1</sup>), while for JRC-BIO and ESA-BIO, the estimates show R<sup>2</sup> of 0.90 and 0.70, respectively, and mean differences of 13.5 and of 21.8 t ha<sup>−1</sup> with respect to the INFC estimates. ITA-CAI estimates are also in good agreement with the INFC estimates (R<sup>2</sup> = 0.93), even if they tend to be slightly biased. The produced maps are hosted on a web-based forest resources management Decision Support System developed under the project AGRIDIGIT (ForestView) and represent a key element in supporting the new Green Deal in Italy, the European Forest Strategy 2030 and the Italian Forest Strategy. © 2022 by the authors.
coveR: an R package for processing digital cover photography images to retrieve forest canopy attributes
Mostra abstract
Key message: coveR is an R package for estimating canopy attributes from digital cover photography (DCP) images. The simplicity of the method and the open-accessibility of coveR can effectively extend the accessibility and applicability of DCP to a wider audience. Abstract: Digital cover photography (DCP) is an increasingly popular tool for estimating canopy cover and leaf area index (LAI). However, existing solutions to process canopy images are predominantly tailored for hemispherical photography, whereas open-access tools for DCP are lacking. We developed an R package (coveR) to support the whole processing of DCP images in an automated, fast, and reproducible way. The package functions, which are designed for step-by-step single-image analysis, can be performed sequentially in a pipeline while ensuring quality-checking of each processing step. A wrapper function ‘coveR()’ is also created to perform all the image processing workflow in a single function. A case study is presented to demonstrate the reliability of canopy attributes derived from coveR in pure beech (Fagus sylvatica L.) stands with variable canopy density and structure. Estimates of gap fraction and effective LAI from DCP were validated against reference measurements obtained from terrestrial laser scanning. By providing a simple, transparent, and flexible image processing procedure, coveR supported the use of DCP for routine measurements and monitoring of forest canopy attributes. This, combined with the possibility to implement DCP in many devices, including smartphones, micro-cameras, and remote trail cameras, can greatly expand the accessibility of the method also by non-experts. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
From model selection to maps: A completely design-based data-driven inference for mapping forest resources
Di Biase
,
Rosa Maria
,
Fattorini
,
Lorenzo
,
Franceschi
,
Sara
,
Grotti
,
Mirko
,
Puletti
,
Nicola
,
Corona
,
P.
density estimation
harmonization
model selection
predictions
pseudopopulation bootstrap
regression estimator
residuals
smoothing parameter
spatial interpolation
Mostra abstract
A completely data-driven, design-based sampling strategy is proposed for mapping a forest attribute within the spatial units tessellating a survey region. Based on sample data, a model is selected, and model parameters are estimated using least-squares criteria for predicting the attribute of interest within units as a linear function of a set of auxiliary variables. The spatial interpolation of residuals arising from model predictions is performed by inverse distance weighting. The leave-one-out cross validation procedure is adopted for selecting the smoothing parameter used for interpolation. The densities of the attributes of interest within units are estimated by summing predictions and interpolated residuals. Finally, density estimates are rescaled to match the total estimate over the survey region obtained by the traditional regression estimator with the total estimate obtained from the map as the sum of the density estimates within units. A bootstrap procedure accounts for the uncertainty. The consistency of the strategy is proven by incorporating previous results. A simulation study is performed and an application for mapping wood volume densities in the forest estate of Rincine (Central Italy) is described. © 2022 John Wiley & Sons Ltd.
Potential of ALOS2 Polarimetric Imagery to Support Management of Poplar Plantations in Northern Italy
Vaglio Laurin
,
Gaia
,
Mattioli
,
Walter
,
Innocenti
,
Simone
,
Lombardo
,
Emanuela
,
Valentini
,
Riccardo
,
Puletti
,
Nicola
Mostra abstract
Poplar is one of the most widespread fast-growing forest species. In Northern Italy, plantations are characterized by large interannual fluctuations, requiring frequent monitoring to inform on wood supply and to manage the stands. The use of radar satellite data is proving useful for forest monitoring, being weather independent and sensitive to the changes in forest canopy structure, but it has been scarcely tested in the case of poplar. Here, L-band ALOS2 (Advanced Land Observing Satellite-2) dual-pol data were tested to detect clear-cut plantations in consecutive years. ALOS2 quad-pol data were used to discriminate among different age classes, a much complex task than detecting poplar plantations extent. Results from different machine learning algorithms indicate that with dual-pol data, poplar forest can be discriminated from clear-cut areas with 80% overall accuracy, similar to what is usually obtained with optical data. With quad-pol data, four age classes were classified with moderate overall accuracy (73%) based on polarimetric decompositions, three 3 age classes with higher accuracy (87%) based on HV band. Sources of error are represented by poplar areas of intermediate age when stems, branches and leaves were not developed enough to detect by scattering mechanisms. This study demonstrates the feasibility of monitoring poplar plantations with satellite radar, which represents a growing source of information thanks to already-planned future satellite missions. © 2022 by the authors.
A georeferenced dataset of nocturnal macrolepidoptera: A tool for forest management and biodiversity conservation
Mostra abstract
In this paper we provide a georeferenced dataset of raw data concerning occurrence and abundance of nocturnal macrolepidoptera, an insect group largely recognized as a good ecological indicator of forest ecosystems. Data have been collected by using light traps located in 15 beech and 20 Calabrian black pine forest lots, 20 of which included in Natura 2000 sites. The sampling was carried out monthly lasting from May to late October 2019 and 2020 in order to cover the entire period during which favourable conditions for adult monitoring occurred, and to encompass phenological changes occurring across seasons in moth diversity. The dataset is composed by a total of 42,834 individuals belonging to 363 species. Due to the relatively small attractive radius of used light traps (about 25 m), georeferenced lepidopteran data can be easily correlated to any kind of spatial environmental variables and forest attributes and to their temporal variations being useful to quantify also the effects of long-term ecological drivers. © 2022
Enhancing wall-to-wall forest structure mapping through detailed co-registration of airborne and terrestrial laser scanning data in Mediterranean forests
Mostra abstract
This paper presents a new co-registration procedure of complementary point clouds captured by both Terrestrial (TLS) and Airborne Laser Scanning (ALS) technologies. Starting from the geographic position of the TLS point cloud, a geometric features recognition algorithm, which evaluates digital terrain models obtained from both ALS and TLS, was developed and implemented in a new GIS software (ForeSight®). As a case study, we tested this new approach using point clouds acquired from both hand-held mobile TLS and ALS sensors over 24 test sites located in a protected area in southern Italy, with the ultimate goal of characterizing the different forest stand structures. From each aligned point cloud, a plot-level spatially explicit index (Enhanced Structural Spatial Index, ESCI) was derived to assess the three-dimensional structure of the considered forest stands. Then, we compared structural features derived from the ESCI index with different computed ALS metrics. Finally, the most correlated ALS metrics were used as predictors to produce an ESCI-map of the entire region of interest. © 2021 Elsevier B.V.
MASTREE+: Time-series of plant reproductive effort from six continents
Hacket-Pain
,
Andrew J.
,
Foest
,
Jessie J.
,
Pearse
,
Ian S.
,
LaMontagne
,
Jalene M.
,
Koenig
,
Walter D.
,
Vacchiano
,
Giorgio
,
Bogdziewicz
,
Michał
,
Caignard
,
Thomas
,
Celebias
,
Paulina
,
van Dormolen
,
Joep
,
Fernández-Martínez
,
Marcos
,
Moris
,
Jose V.
,
Palaghianu
,
Ciprian
,
Pesendorfer
,
Mario B.
,
Satake
,
Akiko
,
Schermer
,
Éliane
,
Tanentzap
,
Andrew J.
,
Thomas
,
Peter A.
,
Vecchio
,
Davide
,
Wion
,
Andreas P.
,
Wohlgemuth
,
Thomas
,
Xue
,
Tingting
,
Abernethy
,
Katharine A.
,
Aravena Acuña
,
Marie Claire
,
Barrera
,
Marcelo Daniel
,
Barton
,
Jessica H.
,
Boutin
,
Stan A.
,
Bush
,
Emma R.
,
Donoso Calderón
,
Sergio R.
,
Carevic
,
Felipe S.
,
Castilho
,
Carolina V.
,
Manuel Cellini
,
Juan
,
Chapman
,
Colin A.
,
Chapman
,
H. M.
,
Chianucci
,
Francesco
,
Costa
,
Patricia Da
,
Croisé
,
Luc
,
Cutini
,
Andrea
,
Dantzer
,
Ben J.
,
DeRose
,
Robert Justin
,
Dikangadissi
,
Jean Thoussaint
,
Dimoto
,
Edmond
,
da Fonseca
,
Fernanda Lopes
,
Gallo
,
Leonardo Ariel
,
Gratzer
,
Georg
,
Greene
,
David F.
,
Hadad
,
Martín Ariel
,
Huertas Herrera
,
Alejandro
,
Jeffery
,
Kathryn J.
,
Johnstone
,
Jill F.
,
Kalbitzer
,
Urs
,
Kantorowicz
,
Władysław
,
Klimas
,
Christie Ann
,
Lageard
,
Jonathan G.A.
,
Lane
,
Jeffrey E.
,
Lapin
,
Katharina
,
Ledwoń
,
Mateusz
,
Leeper
,
Abigail C.
,
Lencinas
,
María Vanessa
,
Lira-Guedes
,
Ana Cláudia
,
Lordon
,
Michael C.
,
Marchelli
,
Paula
,
Marino
,
Shealyn
,
Schmidt van Marle
,
Harald
,
McAdam
,
Andrew G.
,
Momont
,
Ludovic R.W.
,
Nicolas
,
Manuel
,
de Oliveira Wadt
,
Lúcia Helena
,
Panahi
,
Parisa
,
Martínez Pastur
,
Guillermo J.
,
Patterson
,
Thomas W.
,
Luis Peri
,
Pablo
,
Piechnik
,
Łukasz
,
Pourhashemi
,
Mehdi
,
Espinoza Quezada
,
Claudia
,
Roig
,
Fidel Alejandro
,
Peña-Rojas
,
Karen A.
,
Rosas
,
Yamina Micaela
,
Schueler
,
Silvio
,
Seget
,
Barbara
,
Soler
,
Rosina M.
,
Steele
,
Michael A.
,
Toro Manríquez
,
Mónica Del Rosario
,
Tutin
,
Caroline E.G.
,
Ukizintambara
,
Tharcisse
,
White
,
Lee J.T.
,
Yadok
,
Biplang Godwill
,
Willis
,
John L.
,
Zolles
,
Anita
,
Żywiec
,
Magdalena
,
Ascoli
,
Davide
Mostra abstract
Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics. © 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.
Ultrahigh-resolution boreal forest canopy mapping: Combining UAV imagery and photogrammetric point clouds in a deep-learning-based approach
Li
,
Linyuan
,
Mu
,
Xihan
,
Chianucci
,
Francesco
,
Qi
,
Jianbo
,
Jiang
,
Jingyi
,
Zhou
,
Jiaxin
,
Chen
,
Ling
,
Huang
,
Huaguo
,
Yan
,
Guangjian
,
Liu
,
Shouyang
Mostra abstract
Accurate wall-to-wall estimation of forest crown cover is critical for a wide range of ecological studies. Notwithstanding the increasing use of UAVs in forest canopy mapping, the ultrahigh-resolution UAV imagery requires an appropriate procedure to separate the contribution of understorey from overstorey vegetation, which is complicated by the spectral similarity between the two forest components and the illumination environment. In this study, we investigated the integration of deep learning and the combined data of imagery and photogrammetric point clouds for boreal forest canopy mapping. The procedure enables the automatic creation of training sets of tree crown (overstorey) and background (understorey) data via the combination of UAV images and their associated photogrammetric point clouds and expands the applicability of deep learning models with self-supervision. Based on the UAV images with different overlap levels of 12 conifer forest plots that are categorized into “I”, “II” and “III” complexity levels according to illumination environment, we compared the self-supervised deep learning-predicted canopy maps from original images with manual delineation data and found an average intersection of union (IoU) larger than 0.9 for “complexity I” and “complexity II” plots and larger than 0.75 for “complexity III” plots. The proposed method was then compared with three classical image segmentation methods (i.e., maximum likelihood, Kmeans, and Otsu) in the plot-level crown cover estimation, showing outperformance in overstorey canopy extraction against other methods. The proposed method was also validated against wall-to-wall and pointwise crown cover estimates using UAV LiDAR and in situ digital cover photography (DCP) benchmarking methods. The results showed that the model-predicted crown cover was in line with the UAV LiDAR method (RMSE of 0.06) and deviate from the DCP method (RMSE of 0.18). We subsequently compared the new method and the commonly used UAV structure-from-motion (SfM) method at varying forward and lateral overlaps over all plots and a rugged terrain region, yielding results showing that the method-predicted crown cover was relatively insensitive to varying overlap (largest bias of less than 0.15), whereas the UAV SfM-estimated crown cover was seriously affected by overlap and decreased with decreasing overlap. In addition, canopy mapping over rugged terrain verified the merits of the new method, with no need for a detailed digital terrain model (DTM). The new method is recommended to be used in various image overlaps, illuminations, and terrains due to its robustness and high accuracy. This study offers opportunities to promote forest ecological applications (e.g., leaf area index estimation) and sustainable management (e.g., deforestation). © 2022 The Author(s)