Simulation and Visualisation of Functional Landscapes: Effects of the Water Resource Competition Between Plants

Abstract

Vegetation ecosystem simulation and visualisation are challenging topics involving multidisciplinary aspects. In this paper, we present a new generic frame for the simulation of natural phenomena through manageable and interacting models. It focuses on the functional growth of large vegetal ecosystems, showing coherence for scales ranging from the individual plant to communities and with a particular attention to the effects of water resource competition between plants.The proposed approach is based on a model of plant growth in interaction with the environmental conditions. These are deduced from the climatic data (light, temperature, rainfall) and a model of soil hydrological budget. A set of layers is used to store the water resources and to build the interfaces between the environmental data and landscape components: temperature, rain, light, altitude, lakes, plant positions, biomass, cycles, etc. At the plant level, the simulation is performed for each individual by a structural-functional growth model, interacting with the plant's environment. Temperature is spatialised, changing according to altitude, and thus locally controls plant growth speed. The competition for water is based on a soil hydrological model taking into account rainfalls, water runoff, absorption, diffusion, percolation in soil. So far, the incoming light radiation is not studied in detail and is supposed constant.However, competition for light between plants is directly taken into account in the plant growth model.In our implementation, we propose a simple architecture for such a simulator and a simulation scheme to synchronise the water resource updating (on a temporal basis) and the plant growth cycles (determined by the sum of daily temperatures). The visualisation techniques are based on sets of layers, allowing both morphological and functional landscape views and providing interesting tools for ecosystem management.The implementation of the proposed frame leads to encouraging results that are presented and illustrate *

A Functional and Structural Mongolian Scots Pine (Pinus sylvestris var. mongolica) Model Integrating Architecture, Biomass and Effects of Precipitation

“…Le Chevalier et al . proposed a new generic framework for simulating the development of large plant ecosystems using the plant growth engine of the GreenLab model [40] . In our study, we analysed the simulation results related to tree height, basal diameter and biomass of above-ground plant parts for different levels of precipitation.…”

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“…Finally, modelling the interactions with the environment might lead to some difficult questions regarding competition for resources and synchronization of plant growth with the environmental submodels. These issues are those of functional landscape research [31] and a convergence of approaches should be considered in a near future.…”

Towards a Continuous Approach of Functional-Structural Plant Growth

“…The time axis is first divided into intervals on which are defined equation (6)- (9). Then, as explained below, the last phase [τ −1 (τ sen + γ), +∞[ is divided again into intervals corresponding to the the thermal time of senescence τ sen , to adapt the numerical solution of (9).…”

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