Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2022
Sammendrag
UAV, drone, ortho photo, image analysis, deep learning, wheel rut, monitoring, GIS, method
Forfattere
Arne SteffenremSammendrag
Det er ikke registrert sammendrag
Forfattere
Kristina Bringedal GeddeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Sigridur DalmannsdottirSammendrag
Det er ikke registrert sammendrag
Forfattere
Hans Pretzsch Andrés Bravo-Oviedo Torben Hilmers Ricardo Ruiz-Peinado Lluis Coll Magnus Löf Shamim Ahmed Jorge Aldea Christian Ammer Admir Avdagić Ignacio Barbeito Kamil Bielak Felipe Bravo Gediminas Brazaitis Jakub Cerný Catherine Collet Lars Drössler Marek Fabrika Michael Heym Stig-Olof Holm Gro Hylen Aris Jansons Viktor Kurylyak Fabio Lombardi Bratislav Matović Marek Metslaid Renzo Motta Thomas Nord-Larsen Arne Nothdurft Cristóbal Ordóñez Jan den Ouden Maciej Pach Marta Pardos Quentin Ponette Tomas Pérot Ditlev Otto Juel Reventlow Roman Sitko Vit Sramek Mathias Steckel Miroslav Svoboda Enno Uhl Kris Verheyen Sonja Vospernik Barbara Wolff Tzvetan Zlatanov Miren del RíoSammendrag
Heterogeneity of structure can increase mechanical stability, stress resistance and resilience, biodiversity and many other functions and services of forest stands. That is why many silvicultural measures aim at enhancing structural diversity. However, the effectiveness and potential of structuring may depend on the site conditions. Here, we revealed how the stand structure is determined by site quality and results from site-dependent partitioning of growth and mortality among the trees. We based our study on 90 mature, even-aged, fully stocked monocultures of Scots pine (Pinus sylvestris L.) sampled in 21 countries along a productivity gradient across Europe. A mini-simulation study further analyzed the site-dependency of the interplay between growth and mortality and the resulting stand structure. The overarching hypothesis was that the stand structure changes with site quality and results from the site-dependent asymmetry of competition and mortality. First, we show that Scots pine stands structure across Europe become more homogeneous with increasing site quality. The coefficient of variation and Gini coefficient of stem diameter and tree height continuously decreased, whereas Stand Density Index and stand basal area increased with site index. Second, we reveal a site-dependency of the growth distribution among the trees and the mortality. With increasing site index, the asymmetry of both competition and growth distribution increased and suggested, at first glance, an increase in stand heterogeneity. However, with increasing site index, mortality eliminates mainly small instead of all-sized trees, cancels the size variation and reduces the structural heterogeneity. Third, we modelled the site-dependent interplay between growth partitioning and mortality. By scenario runs for different site conditions, we can show how the site-dependent structure at the stand level emerges from the asymmetric competition and mortality at the tree level and how the interplay changes with increasing site quality across Europe. Our most interesting finding was that the growth partitioning became more asymmetric and structuring with increasing site quality, but that the mortality eliminated predominantly small trees, reduced their size variation and thus reversed the impact of site quality on the structure. Finally, the reverse effects of mode of growth partitioning and mortality on the stand structure resulted in the highest size variation on poor sites and decreased structural heterogeneity with increasing site quality. Since our results indicate where heterogeneous structures need silviculture interventions and where they emerge naturally, we conclude that these findings may improve system understanding and modelling and guide forest management aiming at structurally rich forests.
Forfattere
Inge Dox Bertold Mariën Paolo Zuccarini Lorene J. Marchand Peter Prislan Jožica Gričar Omar Flores Friederike Gehrmann Patrick Fonti Holger Lange Josep Peñuelas Matteo CampioliSammendrag
Wood growth phenology of temperate deciduous trees is less studied than leaf phenology, hindering the understanding of their interaction. In order to describe the variability of wood growth and leaf phenology across locations, species and years, we performed phenological observations of both xylem formation and leaf development in three typical temperate forest areas in Western Europe (Northern Spain, Belgium and Southern Norway) for four common deciduous tree species (Fagus sylvatica L., Betula pendula Roth., Populus tremula L. and Quercus robur L.) in 2018, 2019 and 2020, with only beech and birch being studied in the final year. The earliest cambial reactivation in spring occurred at the Belgian stands while the end of cambial activity and wood growth cessation generally occurred first in Norway. Results did not show much consistency across species, sites or years and lacked general patterns, except for the end of cambial activity, which occurred generally first in birch. For all species, the site variation in phenophases (up to three months) was substantially larger than the inter-annual variability (up to six weeks). The timeline of bud-burst and cambium reactivation, as well as of foliar senescence and cessation of wood growth, were variable across species even with the same type of wood porosity. Our results suggest that wood growth and leaf phenology are less well connected than previously thought. Linear models showed that temperature is the dominant driver of wood growth phenology, but with climate zone also having an effect, especially at the start of the growing season. Drought conditions, on the other hand, have a larger effect on the timing of wood growth cessation. Our comprehensive analysis represents the first large regional assessment of wood growth phenology in common European deciduous tree species, providing not only new fundamental insights but also a unique dataset for future modelling applications.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Sigridur DalmannsdottirSammendrag
Det er ikke registrert sammendrag