L-PEACH, an L-systems based model for simulating the architecture and carbon partitioning of growing fruit trees

Modeling carbon partitioning is a complex problem because of the dynamic nature and relationships between carbohydrate partitioning, growth and plant architecture. To date there have been no fruit tree simulation models that have attempted to quantitatively model these three processes simultaneously. In this paper we report on an attempt to develop a detailed model of tree carbon economy in which growth and function of each organ is modeled individually within an architecturally explicit model of canopy growth. L-systems was chosen as the platform for tackling the problem of simultaneous modeling of architecture, carbon partitioning and physiology of growing trees and here we introduce the L-PEACH model. L-PEACH combines the supply/demand concepts of carbon allocation of the previous PEACH model with an L-systems model of tree architecture to create a distributed supply/demand system of carbon allocation in a three dimensional, growing tree. The L-PEACH plant model is expressed in terms of modules that represent plant organs. An organ is represented as one or more elementary sources or sinks for carbohydrates and the whole plant is modeled as a branching network of these sources and sinks, connected by conductive elements. An analogy to an electrical network is used to calculate the flow and partitioning of carbohydrates between the individual components. The model can be used to simulate how crop load, rate of fruit maturity, storage tissue sink capacity, and/or water stress can influence growth and carbohydrate partitioning within a fruit tree.

碳分配建模是一个复杂的问题，因为碳水化合物分配、生长和植株结构之间具有动态特性和相互关系。到目前为止，还没有果树模拟模型试图同时对这三个过程进行定量建模。在本文中，我们报告了一种尝试，即开发一个详细的树木碳经济模型，在该模型中，在一个树冠生长的结构明确的模型内对每个器官的生长和功能分别进行建模。选择L - 系统作为解决生长树木的结构、碳分配和生理同时建模问题的平台，在此我们介绍L - PEACH模型。L - PEACH将先前PEACH模型的碳分配供需概念与树木结构的L - 系统模型相结合，在一棵三维生长的树木中创建了一个分布式的碳分配供需系统。L - PEACH植物模型通过代表植物器官的模块来表示。一个器官被表示为一个或多个碳水化合物的基本源或库，整株植物被建模为这些源和库通过传导元件连接而成的分支网络。通过与电网类比来计算碳水化合物在各个组分之间的流动和分配。该模型可用于模拟作物负载、果实成熟速率、贮藏组织库容量和/或水分胁迫如何影响果树内的生长和碳水化合物分配。