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.
    Estimation of above-ground biomass of large tropical trees with terrestrial LiDAR
    Gonzalez De Tanago, Jose ; Lau, Alvaro ; Bartholomeus, Harm ; Herold, Martin ; Avitabile, Valerio ; Raumonen, Pasi ; Martius, Christopher ; Goodman, Rosa C. ; Disney, Mathias ; Manuri, Solichin ; Burt, Andrew ; Calders, Kim - \ 2018
    Methods in Ecology and Evolution 9 (2018)2. - ISSN 2041-210X - p. 223 - 234.
    1. Tropical forest biomass is a crucial component of global carbon emission estimations. However, calibration and validation of such estimates require accurate and effective methods to estimate in situ above-ground biomass (AGB). Present methods rely on allometric models that are highly uncertain for large tropical trees. Terrestrial laser scanning (TLS) tree modelling has demonstrated to be more accurate than these models to infer forest AGB. Nevertheless, applying TLS methods on tropical large trees is still challenging. We propose a method to estimate AGB of large tropical trees by three-dimensional (3D) tree modelling of TLS point clouds. 2. Twenty-nine plots were scanned with a TLS in three study sites (Peru, Indonesia and Guyana). We identified the largest tree per plot (mean diameter at breast height of 73.5 cm), extracted its point cloud and calculated its volume by 3D modelling its structure using quantitative structure models (QSM) and converted to AGB using species-specific wood density. We also estimated AGB using pantropical and local allometric models. To assess the accuracy of our and allometric methods, we harvest the trees and took destructive measurements. 3. AGB estimates by the TLS–QSM method showed the best agreement in comparison to destructive harvest measurements (28.37% coefficient of variation of root mean square error [CV-RMSE] and concordance correlation coefficient [CCC] of 0.95), outperforming the pantropical allometric models tested (35.6%–54.95% CV-RMSE and CCC of 0.89–0.73). TLS–QSM showed also the lowest bias (overall underestimation of 3.7%) and stability across tree size range, contrasting with the allometric models that showed a systematic bias (overall underestimation ranging 15.2%–35.7%) increasing linearly with tree size. The TLS–QSM method also provided accurate tree wood volume estimates (CV RMSE of 23.7%) with no systematic bias regardless the tree structural characteristics. 4. Our TLS–QSM method accounts for individual tree biophysical structure more effectively than allometric models, providing more accurate and less biased AGB estimates for large tropical trees, independently of their morphology. This non-destructive method can be further used for testing and calibrating new allometric models, reducing the current under-representation of large trees in and enhancing present and past estimates of forest biomass and carbon emissions from tropical forests.
    Tropical forest canopies and their relationships with climate and disturbance: results from a global dataset of consistent field-based measurements
    Pfeifer, Marion ; Gonsamo, Alemu ; Woodgate, William ; Cayuela, Luis ; Marshall, Andrew R. ; Ledo, Alicia ; Paine, Timothy C.E. ; Marchant, Rob ; Burt, Andrew ; Calders, Kim ; Courtney-mustaphi, Colin ; Cuni-sanchez, Aida ; Deere, Nicolas J. ; Denu, Dereje ; Gonzalez De Tanago Meñaca, J. ; Hayward, Robin ; Lau Sarmiento, A.I. ; Macía, Manuel J. ; Olivier, Pieter I. ; Pellikka, Petri ; Seki, Hamidu ; Shirima, Deo ; Trevithick, Rebecca ; Wedeux, Beatrice ; Wheeler, Charlotte ; Munishi, Pantaleo K.T. ; Martin, Thomas ; Mustari, Abdul ; Platts, Philip J. - \ 2018
    Forest Ecosystems 5 (2018). - ISSN 2095-6355 - 14 p.
    Background: Canopy structure, defined by leaf area index (LAI), fractional vegetation cover (FCover) and fraction of absorbed photosynthetically active radiation (fAPAR), regulates a wide range of forest functions and ecosystem services. Spatially consistent field-measurements of canopy structure are however lacking, particularly for the tropics. Methods: Here, we introduce the Global LAI database: a global dataset of field-based canopy structure measurements spanning tropical forests in four continents (Africa, Asia, Australia and the Americas). We use these measurements to test for climate dependencies within and across continents, and to test for the potential of anthropogenic disturbance and forest protection to modulate those dependences. Results: Using data collected from 887 tropical forest plots, we show that maximum water deficit, defined across the most arid months of the year, is an important predictor of canopy structure, with all three canopy attributes declining significantly with increasing water deficit. Canopy attributes also increase with minimum temperature, and with the protection of forests according to both active (within protected areas) and passive measures (through topography). Once protection and continent effects are accounted for, other anthropogenic measures (e.g. human population) do not improve the model. Conclusions: We conclude that canopy structure in the tropics is primarily a consequence of forest adaptation to the maximum water deficits historically experienced within a given region. Climate change, and in particular changes in drought regimes may thus affect forest structure and function, but forest protection may offer some resilience against this effect.
    Capturing forest structure and change – 5 years of laser scanning and future perspectives using UAV based LiDAR
    Bartholomeus, H.M. ; Lau Sarmiento, A.I. ; Gonzalez de Tanago Meñaca, J. ; Herold, M. ; Brede, B. ; Kooistra, L. ; Calders, Kim - \ 2017
    In: SilviLaser 2017 Program. - Blacksburg : Virginia Tech - p. 61 - 62.
    Above-ground biomass assessment of tropical trees with Terrestrial LiDAR and 3D architecture models
    Lau Sarmiento, A.I. ; Gonzalez de Tanago Meñaca, J. ; Bartholomeus, H.M. ; Herold, M. ; Avitabile, V. ; Raumonen, Pasi ; Martius, Christopher ; Goodman, R.C. ; Disney, Mathias ; Manuri, Solichin ; Burt, Andrew ; Calders, Kim - \ 2017
    In: SilviLaser 2017 Program. - Blacksburg : Virginia Tech - p. 123 - 124.
    Data acquisition considerations for Terrestrial Laser Scanning of forest plots
    Wilkes, Phil ; Lau Sarmiento, Alvaro ; Disney, Mathias ; Calders, Kim ; Burt, Andrew ; Gonzalez De Tanago Meñaca, J. ; Bartholomeus, Harm ; Brede, Benjamin ; Herold, Martin - \ 2017
    Remote Sensing of Environment 196 (2017). - ISSN 0034-4257 - p. 140 - 153.
    The poor constraint of forest Above Ground Biomass (AGB) is responsible, in part, for large uncertainties in modelling future climate scenarios. Terrestrial Laser Scanning (TLS) can be used to derive unbiased and non-destructive estimates of tree structure and volume and can, therefore, be used to address key uncertainties in forest AGB estimates. Here we review our experience of TLS sampling strategies from 27 campaigns conducted over the past 5 years, across tropical and temperate forest plots, where data was captured with a RIEGL VZ-400 laser scanner. The focus is on strategies to derive Geometrical Modelling metrics (e.g. tree volume) over forest plots (≥1 ha) which require the accurate co-registration of 10s to 100s of individual point clouds. We recommend a 10 m × 10 m sampling grid as an approach to produce a point cloud with a uniform point distribution, that can resolve higher order branches (down to a few cm in diameter) towards the top of 30+ m canopies and can be captured in a timely fashion i.e. ∼3–6 days per ha. A data acquisition protocol, such as presented here, would facilitate data interoperability and inter-comparison of metrics between instruments/groups, from plot to plot and over time.
    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.
    Terrestrial LiDAR and 3D Reconstruction Models for Large Individual Tree Biomass Estimation in Tropics
    Lau Sarmiento, A.I. ; Herold, M. ; Bartholomeus, H.M. ; Gonzalez de Tanago Meñaca, J. - \ 2016
    Mapping post-deforestation land use in the Brazilian Amazon using Remote Sensing Time Series
    Bewernick, Tom ; Gonzalez de Tanago Meñaca, J. ; Herold, M. ; Verbesselt, J. - \ 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
    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.
    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
    Evaluation of different scan configurations for an effective field procedure on a terrestrial LiDAR scanner in tropical forest
    Lau Sarmiento, A.I. ; Bartholomeus, H.M. ; Gonzalez De Tanago Meñaca, 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.
    Acquisition of terrestrial LIDAR in tropical forest to support ecological research
    Bartholomeus, H. ; Gonzalez De Tanago Meñaca, J. ; Calders, K. ; Lau Sarmiento, A. ; Herold, M. - \ 2014
    The Effects of Landsat Time Series Pre-Processing on Tropical Forest Change Mapping in Vietnam and Ethiopia
    Schultz, M. ; Herold, M. ; Avitabile, V. ; Verbesselt, J. ; Gonzalez de Tanago Meñaca, J. - \ 2013
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