Towards understanding tree root profiles: simulating hydrologically optimal strategies for root distribution

By M. V. Wijk, Willem Bouten. 2001

71 citations recorded by the source corpus.

Abstract. In this modelling study differences in vertical root distributions measured in four contrasting forest locations in the Netherlands were investigated. Root distributions are seen as a reflection of the plant’s optimisation strategy, based on hydrological grounds. The "optimal" root distribution is defined as the one that maximises the water uptake from the root zone over a period of ten years. The optimal root distributions of four forest locations with completely different soil physical characteristics are calculated using the soil hydrological model SWIF. Two different model configurations for root interactions were tested: the standard model configuration in which one single root profile was used (SWIF-NC), and a model configuration in which two root profiles compete for the same available water (SWIF-C). The root profiles were parameterised with genetic algorithms. The fitness of a certain root profile was defined as the amount of water uptake over a simulation period of ten years. The root profiles of SWIF-C were optimised using an evolutionary game. The results showed clear differences in optimal root distributions between the various sites and also between the two model configurations. Optimisation with SWIF-C resulted in root profiles that were easier to interpret in terms of feasible biological strategies. Preferential water uptake in wetter soil regions was an important factor for interpretation of the simulated root distributions. As the optimised root profiles still showed differences with measured profiles, this analysis is presented, not as the final solution for explaining differences in root profiles of vegetation but as a first step using an optimisation theory to increase understanding of the root profiles of trees. Keywords: forest hydrology, optimisation, roots

Subfields: Global and Planetary Change, Mechanical Engineering, Nature and Landscape Conservation

View Paper: https://www.semanticscholar.org/paper/092c83623563d2094b505ef2b3b5626662286add

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In Global and Planetary Change

In Mechanical Engineering

In Nature and Landscape Conservation

Citations in the corpus

The REFLEX project: Comparing different algorithms and implementations for the inversion of a terrestrial ecosystem model against eddy covariance data (2009, methodology): “2008); generic search algorithms that in principle can deal with large numbers of 239 parameters like Genetic Algorithms (Van Wijk and Bouten 2001); an algorithm based on the 240 Metropolis-Hastings algorithm (Metropolis et al. 1953) and using Markov Chain Monte Carlo 241 samplers that recently has…”
Compensatory uptake functions in empirical macroscopic root water uptake models: experimental and numerical analysis (2015, background): “…relating the local (considered soil element) to the bulk average (entire root zone) water condition, regardless of the ratio Ta/Tp. Adiku et al. (2000) and van Wijk and Bouten (2001) considered that RWU pattern from the soil is automatically adjusted to minimize energy expenditure by the plant.”
Vertical Vegetation Structure Below Ground: Scaling from Root to Globe (2005, methodology): “A related approach was used in a model developed by van Wijk and Bouten (2001), in which roots were distributed vertically so as to maximize water”
Mechanisms of plant competition for nutrients, water and light (2013, methodology): “A simulation model of forests in the Netherlands showed that the optimal distribution of roots in the absence of competition was deeper than in the presence of competition (van Wijk & Bouten 2001).”
Root competition: beyond resource depletion (2006, background): “Roots that are closer to the surface generally have a competitive advantage over deeper roots, because, on average, they have access to larger amounts of water and nutrients (van Wijk & Bouten 2001).”
Plant rooting strategies in water‐limited ecosystems (2007, methodology): “van Wijk and Bouten [2001] used a genetic algorithm to identify the optimal root profiles at four sites in the Netherlands, and rooting depths were one of many parameters explored by the genetic algorithm employed by Schwinning and Ehleringer [2001].”
An optimality-based model of the coupled soil moisture and root dynamics (2008, unknown): “Optimality approaches have been explored previously for modelling root water uptake (e.g. Kleidon and Heimann, 1996, 1998; van Wijk and Bouten, 2001; Laio et al. , 2006; Collins and Bras, 2007), but we are only aware of one that modelled a dynamically adapting root distribution (Kleidon and…”
A vertically extended stochastic model of soil moisture in the root zone (2006, result): “This choice, though apparently simplistic, is in accordance with some of the most detailed uptake models available in the literature [e.g., van Dam et al., 1997; Feddes et al. ,2 001;Vrugt et al. ,2 001; van Wijk and Bouten, 2001; Feddes and Raats, 2004].”