About PMA09 Proceedings(pdf file)

Event Program.

• Event location.
  Event will be held in Jinma Hotel
  Location and access maps are available from here (pdf).


• Program Overview
  November 9th : Tutorials
  November 10th : Opening ceremony and scientific sessions
  November 11th : Scientific sessions
  November 12th : Scientific sessions and closing ceremony
  November 13th : Visits
  



• Invited talks
  Functional Structural Plant Models - case LIGNUM. by Risto Sievanen
  Image-based Modeling of Plants and Trees. by Long Quan
  Structural-Functional Model SimRoot and its Applications. by Jonathan P. Lynch
  Modelling Asymmetric Growth in Crowded Plant Communities. by Christian Damgaard
  


• Event Program
  
Detailled event program (pdf file). -> top


• Invited talks
  Functional Structural Plant Models - case LIGNUM. -> top
  Risto Sievänen(1) {http://www.metla.fi/pp/RSie/index-en.htm}, Jari Perttunen(1), Eero Nikinmaa(2), Juan M. Posada(3)
  
  (1)Finnish Forest Research Institute, 01301 Vantaa, Finland
  (2)Department of Forest Ecology, University of Helsinki, 00014 University of Helsinki, Finland
  (3)Programa de Biologia, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
  
  The functional structural plant models (FSPMs) can be defined as models that combine descriptions of metabolic (physiological) processes with a presentation of the 3D structure of a plant. They contain usually the following components 1) Presentation of the plant structure in terms of basic units, 2) Rules of morphological development and 3) Models of metabolic processes that drive the plant growth. The main emphasis in these applications has been individual plants. It is understandable because, due to the detailed description of the plant structure, and consequently, of the local environment of each organ, the FSPMs tend to require a large number of parameters and/or input data. Owing to the large amount of information they contain about the plant to be modeled, they also tend to be computationally heavy. In the following we shortly describe how the three FSPM model components have been realized in the LIGNUM model. Three basic units (Tree segment, Branching point and Bud) are used. We are using the STL template library of C++ to define a blueprint of a tree that can be instantiated by actual representations of the species speci?c components. We are using four generic algorithms for traversing the data structure of the tree and to make calculations. L-systems are used for specifying the morphological development of the trees. We present three examples of applications made using LIGNUM: a calculation of optimal leaf traits in Sugar maple saplings, a system for storing and analyzing information on decay in city trees and simulation of growth of a tree stand.
  
  
  Image-based Modeling of Plants and Trees. -> top
  Long Quan {http://www.cse.ust.hk/~quan/}
  
  The Department of Computer Science, The Hong Kong University of  Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
  
  We present a semi-automatic technique for modeling trees and plants directly from images. Our image-based approach has the distinct advantage that the resulting model inherits the realistic shape and complexity of a real tree or plant. This is possible because the leaves of a tree or a plant all have the same generic shape, and the branches have a natural generative model of self-similarity like a fractal. We designed our modeling system to be interactive, automating the process of shape recovery while relying on the user to provide simple hints on segmentation. Segmentation is performed in both image and 3D spaces, allowing the user to easily visualize its effect immediately. Using the segmented image and 3D data, the geometry of each leaf is then automatically recovered from the multiple views by fitting a deformable leaf model. Our system also allows the user to easily reconstruct branches in a similar manner. We show realistic reconstructions of a variety of trees and plants.
  
  
  Structural-Functional Model SimRoot and its Applications -> top
  Jonathan P. Lynch {http://roots.psu.edu/en/LynchCV}
  
  Department of Horticulture, The Pennsylvania State University, 102 Tyson Building, University Park, PA 16802, USA
  
  SimRoot is a structural-functional model with, in contrast to most structural-functional models, emphasis on the architecture and function of the root system. We use SimRoot as a heuristic tool in our efforts to understand the function of different root traits for acquisition of nutrients and water in low fertility soils and drought environments. We parameterized SimRoot for both maize and bean and are currently able to simulate nutrient uptake for phosphorus and nitrogen in combination with water uptake and photosynthesis. SimRoot is designed to simulate stress responses in a virtual plant with a 'sound' carbon balance sheet. SimRoot is a modular model and can be run in different configurations. The main modules are root growth and shoot growth modules, carbon module, nutrient and water uptake and stress modules. The carbon module is based on LinTul. Both the Barber-Cushman model and Simunek's SWMS can be used for simulating nutrient uptake & transport in the soil. Nutrient stress effects growth by reducing for example the leaf area expansion rate or photosynthetic efficiency of the leaves. SimRoot is designed to work with measurable parameters and uses a predictor-corrected integration method to obtain accurate results, even when positive feedbacks are simulated. We have used SimRoot for:
  1) studying effects of root architecture on inter- and intra root competition for phosphorus,
  2) studying the importance of root architecture for phosphorus uptake in stratified soils
  3) studying the importance of root hair length and density for phosphorus uptake
  4) fractal analysis of root systems
  5) studying the carbon economy of roots
  In two recent studies we simulated the utility of Root Cortical Aerenchyma (RCA) formation under both phosphorus deficiency and drought. RCA, air spaces in the root, is an anatomical trait, usually associated with hypoxia. However, not only hypoxia, but also phosphorus, nitrogen, sulphur deficiency and drought can induce RCA formation. Enhanced oxygen transport has been noted as the main function of RCA formation under hypoxia, but is an unlikely explanation for RCA formation in response to the mentioned nutrient stresses or drought. Our experimental work shows that RCA reduces both the respiration of roots and the phosphorus content. Simulation results, using SimRoot, shows that these small scale effects have relevance for whole plant performance. We assumed that reduced respiration and reduced phosphorus requirements of the roots allows plants to maintain higher root growth rates and thereby increase their soil exploration and nutrient and water uptake.
  
  
  Modelling Asymmetric Growth in Crowded Plant Communities -> top
  Christian Damgaard {http://www.dmu.dk/International/AboutNERI/Departments/TerrestrialEcology/Christian+Damgaard/}
  
  Department of Terrestrial Ecology, National Environmental Research Institute, DK-8600 Silkeborg, Denmark, University of Aarhus
  
  A class of models that may be used to quantify the effect of size-asymmetric competition in crowded plant communities by estimating a community specific degree of size-asymmetric growth for each species in the community is suggested. The model consists of two parts: an individual size-asymmetric growth part, where growth is assumed to be proportional to a power function of the size of the individual, and a term that reduces the relative growth rate as a decreasing function of the individual plant size and the competitive interactions from other plants in the neighbourhood.
  

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