Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    An architectural understanding of natural sway frequencies in trees
    Jackson, T. ; Shenkin, A. ; Moore, J. ; Bunce, A. ; Emmerik, T. Van; Kane, B. ; Burcham, D. ; James, K. ; Selker, J. ; Calders, K. ; Origo, N. ; Disney, M. ; Burt, A. ; Wilkes, P. ; Raumonen, P. ; Gonzalez De Tanago Menaca, J. ; Lau, A. ; Herold, M. ; Goodman, R.C. ; Fourcaud, T. ; Malhi, Y. - \ 2019
    Journal of the Royal Society, Interface 16 (2019)155. - ISSN 1742-5689 - 9 p.
    The relationship between form and function in trees is the subject of a longstanding debate in forest ecology and provides the basis for theories concerning forest ecosystem structure and metabolism. Trees interact with the wind in a dynamic manner and exhibit natural sway frequencies and damping processes that are important in understanding wind damage. Tree-wind dynamics are related to tree architecture, but this relationship is not well understood. We present a comprehensive view of natural sway frequencies in trees by compiling a dataset of field measurement spanning conifers and broadleaves, tropical and temperate forests. The field data show that a cantilever beam approximation adequately predicts the fundamental frequency of conifers, but not that of broadleaf trees. We also use structurally detailed tree dynamics simulations to test fundamental assumptions underpinning models of natural frequencies in trees. We model the dynamic properties of greater than 1000 trees using a finite-element approach based on accurate three-dimensional model trees derived from terrestrial laser scanning data. We show that (1) residual variation, the variation not explained by the cantilever beam approximation, in fundamental frequencies of broadleaf trees is driven by their architecture; (2) slender trees behave like a simple pendulum, with a single natural frequency dominating their motion, which makes them vulnerable to wind damage and (3) the presence of leaves decreases both the fundamental frequency and the damping ratio. These findings demonstrate the value of new three-dimensional measurements for understanding wind impacts on trees and suggest new directions for improving our understanding of tree dynamics from conifer plantations to natural forests.
    Finite element analysis of trees in the wind based on terrestrial laser scanning data
    Jackson, T. ; Shenkin, A. ; Wellpott, A. ; Calders, K. ; Origo, N. ; Disney, M. ; Burt, A. ; Raumonen, P. ; Gardiner, B. ; Herold, M. ; Fourcaud, T. ; Malhi, Y. - \ 2019
    Agricultural and Forest Meteorology 265 (2019). - ISSN 0168-1923 - p. 137 - 144.
    Critical wind speed - Finite element analysis - Resonant frequency - Terrestrial laser scanning - TLS - Wind damage

    Wind damage is an important driver of forest structure and dynamics, but it is poorly understood in natural broadleaf forests. This paper presents a new approach in the study of wind damage: combining terrestrial laser scanning (TLS) data and finite element analysis. Recent advances in tree reconstruction from TLS data allowed us to accurately represent the 3D geometry of a tree in a mechanical simulation, without the need for arduous manual mapping or simplifying assumptions about tree shape. We used this simulation to predict the mechanical strains produced on the trunks of 21 trees in Wytham Woods, UK, and validated it using strain data measured on these same trees. For a subset of five trees near the anemometer, the model predicted a five-minute time-series of strain with a mean cross-correlation coefficient of 0.71, when forced by the locally measured wind speed data. Additionally, the maximum strain associated with a 5 ms−1 or 15 ms-1 wind speed was well predicted by the model (N = 17, R2 = 0.81 and R2 = 0.79, respectively). We also predicted the critical wind speed at which the trees will break from both the field data and models and find a good overall agreement (N = 17, R2 = 0.40). Finally, the model predicted the correct trend in the fundamental frequencies of the trees (N = 20, R2 = 0.38) although there was a systematic underprediction, possibly due to the simplified treatment of material properties in the model. The current approach relies on local wind data, so must be combined with wind flow modelling to be applicable at the landscape-scale or over complex terrain. This approach is applicable at the plot level and could also be applied to open-grown trees, such as in cities or parks.

    Application of terrestrial LiDAR and modelling of tree branching structure for plant-scaling models in tropical forest trees
    Lau Sarmiento, A.I. ; Bartholomeus, H.M. ; Herold, M. ; Martius, Christopher ; Malhi, Yadvinder ; Bentley, Lisa Patrick ; Shenkin, Alexander ; Raumonen, P. - \ 2017
    Terrestrial LiDAR and 3D Reconstruction Models for Estimation of Large Tree Biomass in the Tropics
    Lau Sarmiento, A.I. ; Gonzalez de Tanago Meñaca, J. ; Bartholomeus, H.M. ; Herold, M. ; Raumonen, P. ; Avitabile, V. ; Martius, Christopher ; Goodman, R.M. ; Manuri, Solichin - \ 2016
    - 1 p.
    Application of Terrestrial LiDAR and Modelling of Tree Branching Structure for Plant-scaling Models in Tropical Forest Trees
    Lau Sarmiento, A.I. ; Bartholomeus, H.M. ; Herold, M. ; Martius, Christopher ; Malhi, Yadvinder ; Bentley, Lisa Patrick ; Shenkin, Alexander ; Raumonen, P. - \ 2016
    Quantification of Tropical Forest Biomass with Terrestrial LiDAR and 3D Tree Quantitative Structure Modelling
    Gonzalez deTanago Meñaca, J. ; Lau Sarmiento, A.I. ; Bartholomeus, H.M. ; Herold, M. ; Raumonen, P. ; Avitabile, V. ; Martius, Christopher ; Joseph, Shijo - \ 2016
    3D Measurements of Tropical Forest Structure for BIOMASS, Morphology and Calibration and Validation of Satellite Observations
    Disney, Mathias ; Burt, Andrew ; Calders, K. ; Raumonen, P. ; Herold, M. ; Lewis, P. ; Lewis, S. ; Boni Vicari, M. ; Rowland, L. ; Meir, P. ; Mitchard, Edward - \ 2016
    New measurements of biomass and structure in tropical forests
    Disney, M. ; Burt, A. ; Calders, K. ; Cuni Sanchez, A. ; Avitabile, V. ; Lewis, S. ; Gonzalez de Tanago Meñaca, J. ; Herold, M. ; Raumonen, P. ; Lewis, P. - \ 2015
    Terrestrial Laser Scanning for measuring forest biomass change
    Lau Sarmiento, A.I. ; Calders, K. ; Herold, M. ; Avitabile, V. ; Raumonen, P. ; Gonzalez De Tanago Meñaca, J. ; Bartholomeus, H.M. - \ 2015
    Terrestrial LiDAR and 3D tree Quantitative Structure Model for quantification of aboveground biomass loss from selective logging in a tropical rainforest of Peru
    Gonzalez De Tanago Meñaca, J. ; Bartholomeus, H.M. ; Joseph, Shijo ; Herold, M. ; Avitabile, V. ; Goodman, R.M. ; Raumonen, P. ; Burt, A. - \ 2015
    In: Proceedings of SilviLaser 2015. - - p. 119 - 121.
    Application of terrestrial LiDAR and modelling of tree branching structure for plant-scaling models in tropical forest trees
    Lau Sarmiento, A.I. ; Bartholomeus, H.M. ; Herold, M. ; Martius, C. ; Malhi, Y. ; Bentley, L.P. ; Shenkin, A. ; Raumonen, P. - \ 2015
    In: Proceedings of the SilviLaser 2015 conference. - - p. 3 - 3.
    Massive-scale tree modelling from TLS data
    Raumonen, P. ; Casella, E. ; Calders, K. ; Murphy, S. ; Åkerblom, M. ; Kaasalainen, M. - \ 2015
    In: Proceedings of the ISPRS Annals. - - p. 189 - 196.
    This paper presents a method for reconstructing automatically the quantitative structure model of every tree in a forest plot from terrestrial laser scanner data. A new feature is the automatic extraction of individual trees from the point cloud. The method is tested with a 30-m diameter English oak plot and a 80-m diameter Australian eucalyptus plot. For the oak plot the total biomass was overestimated by about 17 %, when compared to allometry (N = 15), and the modelling time was about 100 min with a laptop. For the eucalyptus plot the total biomass was overestimated by about 8.5 %, when compared to a destructive reference (N = 27), and the modelling time was about 160 min. The method provides accurate and fast tree modelling abilities for, e.g., biomass estimation and ground truth data for airborne measurements at a massive ground scale.
    Nondestructive estimates of above-ground biomass using terrestrial laser scanning
    Calders, K. ; Newnham, G. ; Burt, A. ; Murphy, S. ; Raumonen, P. ; Herold, M. ; Culvenor, D. ; Avitabile, V. ; Disney, M. ; Armston, J. ; Kaasalainen, M. - \ 2015
    Methods in Ecology and Evolution 6 (2015)2. - ISSN 2041-210X - p. 198 - 208.
    carbon-density - tree - lidar - models - equations - systems - volume - stocks
    Allometric equations are currently used to estimate above-ground biomass (AGB) based on the indirect relationship with tree parameters. Terrestrial laser scanning (TLS) can measure the canopy structure in 3D with high detail. In this study, we develop an approach to estimate AGB from TLS data, which does not need any prior information about allometry. We compare these estimates against destructively harvested AGB estimates and AGB derived from allometric equations. We also evaluate tree parameters, diameter at breast height (DBH) and tree height, estimated from traditional field inventory and TLS data. Tree height, DBH and AGB data are collected through traditional forest inventory, TLS and destructive sampling of 65 trees in a native Eucalypt Open Forest in Victoria, Australia. Single trees are extracted from the TLS data and quantitative structure models are used to estimate the tree volume directly from the point cloud data. AGB is inferred from these volumes and basic density information and is then compared with the estimates derived from allometric equations and destructive sampling. AGB estimates derived from TLS show a high agreement with the reference values from destructive sampling, with a concordance correlation coefficient (CCC) of 0·98. The agreement between AGB estimates from allometric equations and the reference is lower (CCC = 0·68–0·78). Our TLS approach shows a total AGB overestimation of 9·68% compared to an underestimation of 36·57–29·85% for the allometric equations. The error for AGB estimates using allometric equations increases exponentially with increasing DBH, whereas the error for AGB estimates from TLS is not dependent on DBH. The TLS method does not rely on indirect relationships with tree parameters or calibration data and shows better agreement with the reference data compared to estimates from allometric equations. Using 3D data also enables us to look at the height distributions of AGB, and we demonstrate that 80% of the AGB at plot level is located in the lower 60% of the trees for a Eucalypt Open Forest. This method can be applied in many forest types and can assist in the calibration and validation of broad-scale biomass maps.
    Terrestrial LiDAR and 3D tree reconstruction modeling for quantification of biomass loss and characterization of impacts of selective logging in tropical forest of Peruvian Amazon. Multi-sensor assessment, combining near and remote sensing
    Gonzalez De Tanago Meñaca, J. ; Joseph, Shijo ; Herold, M. ; Goodman, R.M. ; Bartholomeus, H.M. ; Avitabile, V. ; Raumonen, P. ; Calders, K. ; Lau Sarmiento, A.I. ; Janovec, J. - \ 2014
    New applications of 3D measurement and modelling for quantifying forest structure and biomass
    Disney, M. ; Burt, A. ; Calders, K. ; Raumonen, P. ; Gonzalez De Tanago Meñaca, J. ; Cuni Sanchez, A. ; Avitabile, V. ; Herold, M. ; Armston, J. ; Lewis, S. ; Lines, E. ; Lewis, P. - \ 2014
    In: Proceedings of the IC Global Vegetation Monitoring and Modeling (GV2M). - - p. 208 - 209.
    Non-destructive estimations of above ground biomass using terrestrial LIDAR
    Calders, K. ; Newnham, G. ; Herold, M. ; Murphy, S. ; Raumonen, P. ; Culvenor, D. ; Burt, A. ; Avitabile, V. ; Armston, J. ; Disney, M. - \ 2014
    In: Proceedings of the IC Global Vegetation Monitoring and Modeling (GV2M). - - p. 217 - 218.
    Estimating above ground biomass from terrestrial laser scanning in Australian Eucalypt open forest
    Calders, K. ; Newnham, G. ; Herold, M. ; Murphy, S. ; Culvenor, D. ; Raumonen, P. ; Burt, A. ; Armston, J. ; Avitabile, V. ; Disney, M. - \ 2013
    In: Proceedings SilviLaser 2013, 9-11 October, Beijing, China. - - p. 90 - 97.
    Terrestrial laser scanning (TLS) produces 3D data with high detail and accuracy. In this paper we explore the potential of TLS data in combination with a method for reconstruction tree structure to estimate above ground biomass (AGB) in Australian eucalypt forest. Single trees are isolated from the registered TLS point cloud and are used as input for the reconstruction method. We explore the impact of different input parameters on the reconstruction and compare inferred AGB estimates from volume reconstruction and basic density with destructively sampled reference values. Based on a limited number of samples, regression analysis demonstrated R2 of 0.98 to 0.99, with an intercept of 110 kg for unfiltered TLS point clouds and 19.8 kg for filtered point clouds. These initial results demonstrate the potential of tree reconstruction from TLS for rapid, repeatable and robust AGB estimation.
    Rapid characterisation of forest structure from TLS and 3D modelling
    Burt, A. ; Disney, M.I. ; Raumonen, P. ; Armston, J. ; Calders, K. ; Lewis, P. - \ 2013
    In: Proceedings International Geoscience and Remote Sensing Symposium (IGARSS 2013), Melbourne, Australia, 21 - 26 July, 2013. - Melbourne, Australia : - p. 3387 - 3390.
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