1
|
Jackson T, Shenkin A, Moore J, Bunce A, van Emmerik T, 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 RC, Fourcaud T, Malhi Y. An architectural understanding of natural sway frequencies in trees. J R Soc Interface 2019; 16:20190116. [PMID: 31164076 DOI: 10.1098/rsif.2019.0116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- T Jackson
- 1 Environmental Change Institute, School of Geography and the Environment, University of Oxford , Oxford OX1 3QY , UK
| | - A Shenkin
- 1 Environmental Change Institute, School of Geography and the Environment, University of Oxford , Oxford OX1 3QY , UK
| | - J Moore
- 2 Scion , 49 Sala Street, Rotorua 3010 , New Zealand
| | - A Bunce
- 3 Department of Natural Resources, University of Connecticut , Mansfield, CT 06269 , USA
| | - T van Emmerik
- 4 Water Resources Section, Delft University of Technology , Stevinweg 1, 2628 CN, Delft , The Netherlands.,5 Hydrology and Quantitative Water Management Group, Wageningen University , Wageningen , The Netherlands
| | - B Kane
- 6 Department of Environmental Conservation, University of Massachusetts , Amherst, MA 01003 , USA
| | - D Burcham
- 7 Centre for Urban Greenery and Ecology , National Parks Board, 259569 Singapore
| | - K James
- 8 School of Ecosystem and Forest Sciences, Faculty of Science, University of Melbourne , Melbourne , Australia
| | - J Selker
- 9 Oregon State University , Corvallis, OR 97331 , USA
| | - K Calders
- 10 CAVElab - Computational and Applied Vegetation Ecology, Ghent University , Ghent , Belgium
| | - N Origo
- 11 Earth Observation, Climate and Optical Group, National Physical Laboratory , Hampton Road, Teddington, Middlesex TW11 0LW , UK.,12 Department of Geography, University College London , London WC1E 6BT , UK
| | - M Disney
- 12 Department of Geography, University College London , London WC1E 6BT , UK.,13 NERC National Centre for Earth Observation (NCEO) , Leicester , UK
| | - A Burt
- 12 Department of Geography, University College London , London WC1E 6BT , UK
| | - P Wilkes
- 12 Department of Geography, University College London , London WC1E 6BT , UK.,13 NERC National Centre for Earth Observation (NCEO) , Leicester , UK
| | - P Raumonen
- 14 Tampere University of Technology , Korkeakoulunkatu 10, 33720 Tampere , Finland
| | - J Gonzalez de Tanago Menaca
- 15 Laboratory of Geo-Information Science and Remote Sensing, Wageningen University , Droevendaalsesteeg 3, 6708 PB Wageningen , The Netherlands.,16 Center for International Forestry Research (CIFOR) , PO Box 0113 BOCBD, Bogor 16000 , Indonesia
| | - A Lau
- 15 Laboratory of Geo-Information Science and Remote Sensing, Wageningen University , Droevendaalsesteeg 3, 6708 PB Wageningen , The Netherlands.,16 Center for International Forestry Research (CIFOR) , PO Box 0113 BOCBD, Bogor 16000 , Indonesia
| | - M Herold
- 15 Laboratory of Geo-Information Science and Remote Sensing, Wageningen University , Droevendaalsesteeg 3, 6708 PB Wageningen , The Netherlands
| | - R C Goodman
- 17 Department of Forest Ecology and Management, Swedish University of Agricultural Sciences , Umeå , Sweden
| | - T Fourcaud
- 18 AMAP, University of Montpellier, CIRAD, CNRS, INRA, IRD , Montpellier , France
| | - Y Malhi
- 1 Environmental Change Institute, School of Geography and the Environment, University of Oxford , Oxford OX1 3QY , UK
| |
Collapse
|