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Pubblicazioni Scientifiche
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Comparison of TLS against traditional surveying method for stem taper modelling. A case study in European beech (Fagus sylvatica L.) forests of mount Amiata
Torresan
,
C.
,
Pelleri
,
F.
,
Manetti
,
Maria Chiara
,
Becagli
,
Claudia
,
Castaldi
,
Cristiano
,
Notarangelo
,
Monica
,
Chiavetta
,
U.
Mostra abstract
Traditionally, taper equations are developed from measurements collected through a destructive sampling of trees. Terrestrial laser scanning (TLS) enables high levels of accuracy of individual tree parameters measurement avoiding tree felling. With this study, we wanted to assess the performance of two approaches to calibrate a taper function: using stem diameters extracted from TLS point clouds and measured at different tree heights with the traditional and usual forest instruments. We compared the performance of four taper equations built with data collected by TLS and traditional survey in a European beech (Fagus sylvatica L.) forests of mount Amiata (Tuscany Region, Italy). We computed the volume of stem sections 1.00 m long by integrating the most performing TLS-based taper equation and by the Huber, Smalian and cone formulas applied on the diameter and height values measured with the traditional field surveys. We conducted the analysis of error distribution in volume estimates computed integrating the most performing TLS-based taper function along the stem. We tested if the differences in the volume estimate of the two methods were significant. Schumacher and Hall (1933) equation was the most performing taper function both in case of using TLS and traditional surveyed data, being the TLS-based function more performant (rRMSE = 6.90% vs 9.17%). Its performance did not increase when diameter values were extracted from TLS point clouds with a higher frequency (i.e. 25.0 cm vs 1.00 m). By integrating the TLS-based Schumacher and Hall (1933) function, the sections with the highest error resulted from 5.00 to 7.00 m of stem height (i.e. RMSE from 14.72 to 19.14 dm<sup>3</sup> and rRMSE from 13.00 to 17.76%). This study case represents the first attempts to develop a taper equation for European beech of mount Amiata using values of stem diameter and height extracted from the TLS point cloud. The results demonstrated that TLS produces the same stem volume estimates as traditional method avoiding falling trees. © 2021 Centro di Ricerca per la Selvicoltura, Consiglio per la Ricerca in Agricoltura e l'Analisi dell'Economia Agraria. All rights reserved.
Handbook of field sampling for multi-taxon biodiversity studies in European forests
Burrascano
,
Sabina
,
Trentanovi
,
Giovanni
,
Paillet
,
Yoan
,
Heilmann-Clausen
,
Jacob
,
Giordani
,
P.
,
Bagella
,
Simonetta
,
Bravo-Oviedo
,
Andrés
,
Campagnaro
,
Thomas
,
Campanaro
,
Alessandro
,
Chianucci
,
Francesco
,
de Smedt
,
Pallieter
,
Itziar
,
García Mijangos
,
Matošević
,
Dinka
,
Sitzia
,
Tommaso
,
Aszalós
,
Réka
,
Brazaitis
,
Gediminas
,
Cutini
,
Andrea
,
D'Andrea
,
Ettore
,
Doerfler
,
Inken
,
Hofmeister
,
Jeňýk
,
Hošek
,
Jan
,
Janssen
,
Philippe
,
Kepfer-Rojas
,
Sebastian
,
Korboulewsky
,
Nathalie
,
Kozák
,
Daniel
,
Lachat
,
Thibault
,
Lõhmus
,
Asko
,
López
,
Rosana
,
Mårell
,
Anders
,
Matula
,
Radim
,
Mikoláš
,
Martin
,
Munzi
,
Silvana
,
Nordén
,
Björn
,
Pärtel
,
Meelis
,
Penner
,
Johannes
,
Runnel
,
Kadri
,
Schall
,
Peter
,
Svoboda
,
Miroslav
,
Tinya
,
Flóra
,
Ujházyová
,
Mariana
,
Vandekerkhove
,
Kris
,
Verheyen
,
Kris
,
Xystrakis
,
Fotios
,
Ódor
,
Péter
Mostra abstract
Forests host most terrestrial biodiversity and their sustainable management is crucial to halt biodiversity loss. Although scientific evidence indicates that sustainable forest management (SFM) should be assessed by monitoring multi-taxon biodiversity, most current SFM criteria and indicators account only for trees or consider indirect biodiversity proxies. Several projects performed multi-taxon sampling to investigate the effects of forest management on biodiversity, but the large variability of their sampling approaches hampers the identification of general trends, and limits broad-scale inference for designing SFM. Here we address the need of common sampling protocols for forest structure and multi-taxon biodiversity to be used at broad spatial scales. We established a network of researchers involved in 41 projects on forest multi-taxon biodiversity across 13 European countries. The network data structure comprised the assessment of at least three taxa, and the measurement of forest stand structure in the same plots or stands. We mapped the sampling approaches to multi-taxon biodiversity, standing trees and deadwood, and used this overview to provide operational answers to two simple, yet crucial, questions: what to sample? How to sample? The most commonly sampled taxonomic groups are vascular plants (83% of datasets), beetles (80%), lichens (66%), birds (66%), fungi (61%), bryophytes (49%). They cover different forest structures and habitats, with a limited focus on soil, litter and forest canopy. Notwithstanding the common goal of assessing forest management effects on biodiversity, sampling approaches differed widely within and among taxonomic groups. Differences derive from sampling units (plots size, use of stand vs. plot scale), and from the focus on different substrates or functional groups of organisms. Sampling methods for standing trees and lying deadwood were relatively homogeneous and focused on volume calculations, but with a great variability in sampling units and diameter thresholds. We developed a handbook of sampling methods (SI 3) aimed at the greatest possible comparability across taxonomic groups and studies as a basis for European-wide biodiversity monitoring programs, robust understanding of biodiversity response to forest structure and management, and the identification of direct indicators of SFM. © 2021 The Authors