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Pubblicazioni Scientifiche
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Mapping Understory Vegetation Density in Mediterranean Forests: Insights from Airborne and Terrestrial Laser Scanning Integration
forest biodiversity
lidar
terrestrial laser scanner
forest structure
spatial prediction
voxelization
Mostra abstract
The understory is an essential ecological and structural component of forest ecosystems. The lack of efficient, accurate, and objective methods for evaluating and quantifying the spatial spread of understory characteristics over large areas is a challenge for forest planning and management, with specific regard to biodiversity and habitat governance. In this study, we used terrestrial and airborne laser scanning (TLS and ALS) data to characterize understory in a European beech and black pine forest in Italy. First, we linked understory structural features derived from traditional field measurements with TLS metrics, then, we related such metrics to the ones derived from ALS. Results indicate that (i) the upper understory density (5–10 m above ground) is significantly associated with two ALS metrics, specifically the mean height of points belonging to the lower third of the ALS point cloud within the voxel (HM<inf>1/3</inf>) and the corresponding standard deviation (SD<inf>1/3</inf>), while (ii) for the lower understory layer (2–5 m above ground), the most related metric is HM<inf>1/3</inf> alone. As an example application, we have produced a map of forest understory for each layer, extending over the entire study region covered by ALS data, based on the developed spatial prediction models. With this study, we also demonstrated the power of hand-held mobile-TLS as a fast and high-resolution tool for measuring forest structural attributes and obtaining relevant ecological data. © 2023 by the authors.
Masting is uncommon in trees that depend on mutualist dispersers in the context of global climate and fertility gradients
Qiu
,
Tong
,
Aravena Acuña
,
Marie Claire
,
Ascoli
,
Davide
,
Bergeron
,
Yves
,
Bogdziewicz
,
Michał
,
Boivin
,
Thomas
,
Bonal
,
Raúl
,
Caignard
,
Thomas
,
Cailleret
,
Maxime
,
Calama
,
Rafael A.
,
Calderon
,
Sergio Donoso
,
Camarero
,
Jesús Julio
,
Chang-Yang
,
Chia Hao
,
Chave
,
Jérôme
,
Chianucci
,
Francesco
,
Courbaud
,
Benoít
,
Cutini
,
Andrea
,
Das
,
Adrian J.
,
Delpierre
,
Nicolas
,
Delzon
,
Sylvain
,
Dietze
,
Michael C.
,
Dormont
,
Laurent
,
Espelta
,
Josep Maria
,
Fahey
,
Timothy J.
,
Farfan-Rios
,
William R.
,
Franklin
,
Jerry F.
,
Gehring
,
Catherine A.
,
Gilbert
,
Gregory S.
,
Gratzer
,
Georg
,
Greenberg
,
Cathryn H.
,
Guignabert
,
Arthur
,
Guo
,
Qinfeng
,
Hacket-Pain
,
Andrew J.
,
Hampe
,
Arndt
,
Han
,
Qingmin
,
Holik
,
Jan
,
Hoshizaki
,
K.
,
Ibáñez
,
Inés
,
Johnstone
,
Jill F.
,
Journé
,
Valentin
,
Kitzberger
,
Thomas A.
,
Knops
,
Johannes Michael Hubertus
,
Kunstler
,
Georges
,
Kurokawa
,
Hiroko
,
Lageard
,
Jonathan G.A.
,
LaMontagne
,
Jalene M.
,
Lefèvre
,
François
,
Leininger
,
Theodor D.
,
Limousin
,
Jean Marc
,
Lutz
,
James A.
,
Macias
,
Diana S.
,
Mårell
,
Anders
,
McIntire
,
Eliot J.B.
,
Moore
,
Christopher M.
,
Moran
,
Emily V.
,
Motta
,
Renzo
,
Myers
,
Jonathan A.
,
Nagel
,
Thomas A.
,
Naoe
,
Shoji
,
Noguchi
,
Mahoko
,
Oguro
,
Michio
,
Parmenter
,
Robert R.
,
Pearse
,
Ian S.
,
Pérez-Ramos
,
Ignacio M.
,
Piechnik
,
Łukasz
,
Podgórski
,
Tomasz
,
Poulsen
,
John R.
,
Redmond
,
Miranda D.
,
Reid
,
Chantal D.
,
Rodman
,
Kyle C.
,
Rodríguez-Sánchez
,
Francisco
,
Šamonil
,
Pavel
,
Sanguinetti
,
Javier D.
,
Scher
,
C. Lane
,
Seget
,
Barbara
,
Sharma
,
Shubhi
,
Shibata
,
Mitsue
,
Silman
,
Miles R.
,
Steele
,
Michael A.
,
Stephenson
,
Nathan L.
,
Straub
,
Jacob N.
,
Sutton
,
Samantha
,
Swenson
,
Jennifer J.
,
Swift
,
Margaret
,
Thomas
,
Peter A.
,
Uríarte
,
María
,
Vacchiano
,
Giorgio
,
Whipple
,
Amy Vaughn
,
Whitham
,
Thomas G.
,
Wion
,
Andreas P.
,
Wright
,
Stuart Joseph
,
Zhu
,
Kai
,
Zimmerman
,
Jess K.
,
Żywiec
,
Magdalena
,
Clark
,
James S.
Mostra abstract
The benefits of masting (volatile, quasi-synchronous seed production at lagged intervals) include satiation of seed predators, but these benefits come with a cost to mutualist pollen and seed dispersers. If the evolution of masting represents a balance between these benefits and costs, we expect mast avoidance in species that are heavily reliant on mutualist dispersers. These effects play out in the context of variable climate and site fertility among species that vary widely in nutrient demand. Meta-analyses of published data have focused on variation at the population scale, thus omitting periodicity within trees and synchronicity between trees. From raw data on 12 million tree-years worldwide, we quantified three components of masting that have not previously been analysed together: (i) volatility, defined as the frequency-weighted year-to-year variation; (ii) periodicity, representing the lag between high-seed years; and (iii) synchronicity, indicating the tree-to-tree correlation. Results show that mast avoidance (low volatility and low synchronicity) by species dependent on mutualist dispersers explains more variation than any other effect. Nutrient-demanding species have low volatility, and species that are most common on nutrient-rich and warm/wet sites exhibit short periods. The prevalence of masting in cold/dry sites coincides with climatic conditions where dependence on vertebrate dispersers is less common than in the wet tropics. Mutualist dispersers neutralize the benefits of masting for predator satiation, further balancing the effects of climate, site fertility and nutrient demands. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.
Linking seed size and number to trait syndromes in trees
Bogdziewicz
,
Michał
,
Aravena Acuña
,
Marie Claire
,
Andrus
,
Robert A.
,
Ascoli
,
Davide
,
Bergeron
,
Yves
,
Brveiller
,
Daniel
,
Boivin
,
Thomas
,
Bonal
,
Raúl
,
Caignard
,
Thomas
,
Cailleret
,
Maxime
,
Calama
,
Rafael A.
,
Calderon
,
Sergio Donoso
,
Camarero
,
Jesús Julio
,
Chang-Yang
,
Chia Hao
,
Chave
,
Jérôme
,
Chianucci
,
Francesco
,
Cleavitt
,
Natalie L.
,
Courbaud
,
Benoít
,
Cutini
,
Andrea
,
Curt
,
Thomas
,
Das
,
Adrian J.
,
Davi
,
Hendrik
,
Delpierre
,
Nicolas
,
Delzon
,
Sylvain
,
Dietze
,
Michael C.
,
Dormont
,
Laurent
,
Farfan-Rios
,
William R.
,
Gehring
,
Catherine A.
,
Gilbert
,
Gregory S.
,
Gratzer
,
Georg
,
Greenberg
,
Cathryn H.
,
Guignabert
,
Arthur
,
Guo
,
Qinfeng
,
Hacket-Pain
,
Andrew J.
,
Hampe
,
Arndt
,
Han
,
Qingmin
,
Hoshizaki
,
K.
,
Ibáñez
,
Inés
,
Johnstone
,
Jill F.
,
Journé
,
Valentin
,
Kitzberger
,
Thomas A.
,
Knops
,
Johannes Michael Hubertus
,
Kunstler
,
Georges
,
Kobe
,
Richard K.
,
Lageard
,
Jonathan G.A.
,
LaMontagne
,
Jalene M.
,
Ledwoń
,
Mateusz
,
Leininger
,
Theodor D.
,
Limousin
,
Jean Marc
,
Lutz
,
James A.
,
Macias
,
Diana S.
,
Mårell
,
Anders
,
McIntire
,
Eliot J.B.
,
Moran
,
Emily V.
,
Motta
,
Renzo
,
Myers
,
Jonathan A.
,
Nagel
,
Thomas A.
,
Naoe
,
Shoji
,
Noguchi
,
Mahoko
,
Oguro
,
Michio
,
Kurokawa
,
Hiroko
,
Ourcival
,
Jean Marc
,
Parmenter
,
Robert R.
,
Pérez-Ramos
,
Ignacio M.
,
Piechnik
,
Łukasz
,
Podgórski
,
Tomasz
,
Poulsen
,
John R.
,
Qiu
,
Tong
,
Redmond
,
Miranda D.
,
Reid
,
Chantal D.
,
Rodman
,
Kyle C.
,
Šamonil
,
Pavel
,
Holik
,
Jan
,
Scher
,
C. Lane
,
van Marle
,
Harald Schmidt
,
Seget
,
Barbara
,
Shibata
,
Mitsue
,
Sharma
,
Shubhi
,
Silman
,
Miles R.
,
Steele
,
Michael A.
,
Straub
,
Jacob N.
,
Sun
,
I. Fang
,
Sutton
,
Samantha
,
Swenson
,
Jennifer J.
,
Thomas
,
Peter A.
,
Uríarte
,
María
,
Vacchiano
,
Giorgio
,
Veblen
,
Thomas Thorstein
,
Wright
,
Boyd R.
,
Wright
,
Stuart Joseph
,
Whitham
,
Thomas G.
,
Zhu
,
Kai
,
Zimmerman
,
Jess K.
,
Żywiec
,
Magdalena
,
Clark
,
James S.
Mostra abstract
Aim: Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits that are closely linked to fitness. We tested whether the link between traits and seed number and seed size is consistent with two hypotheses, termed the leaf economics spectrum and the plant size syndrome, or whether reproduction represents an independent dimension related to a seed size–seed number trade-off. Location: Most of the data come from Europe, North and Central America and East Asia. A minority of the data come from South America, Africa and Australia. Time period: 1960–2022. Major taxa studied: Trees. Methods: We gathered 12 million observations of the number of seeds produced in 784 tree species. We estimated the number of seeds produced by individual trees and scaled it up to the species level. Next, we used principal components analysis and generalized joint attribute modelling (GJAM) to map seed number and size on the tree traits spectrum. Results: Incorporating seed size and number into trait analysis while controlling for environment and phylogeny with GJAM exposes relationships in trees that might otherwise remain hidden. Production of the large total biomass of seeds [product of seed number and seed size; hereafter, species seed productivity (SSP)] is associated with high leaf area, low foliar nitrogen, low specific leaf area (SLA) and dense wood. Production of high seed numbers is associated with small seeds produced by nutrient-demanding species with softwood, small leaves and high SLA. Trait covariation is consistent with opposing strategies: one fast-growing, early successional, with high dispersal, and the other slow-growing, stress-tolerant, that recruit in shaded conditions. Main conclusions: Earth system models currently assume that reproductive allocation is indifferent among plant functional types. Easily measurable seed size is a strong predictor of the seed number and species seed productivity. The connection of SSP with the functional traits can form the first basis of improved fecundity prediction across global forests. © 2023 John Wiley & Sons Ltd.