【作者】 唐卫东；

【导师】 李萍萍；

【作者基本信息】 江苏大学 ， 农业生物环境与能源工程， 2007， 博士

【摘要】 在建立植物生长模型时同时考虑植物的形态结构与生理功能变化,是构建反映植物生长规律的虚拟植物模型的关键问题,同时也能增强模型在现代农业生产中的应用。本文主要以北固山湿地优势植物芦苇作为对象,在大量试验观测基础上研究并建立芦苇的生长模拟模型,进而构建出芦苇的虚拟植物模拟模型及其可视化模型。在此基础上开发一个参数化虚拟植物生长原型系统,对芦苇植株在不同参数条件下的生长进行了模拟,从而通过直观的可视化方式为湿地芦苇植物生长发育状况的分析和预测提供理论依据和技术基础。本文的主要工作包括以下内容:1)提出虚拟植物生长的结构功能参考模型。依据虚拟植物的结构功能模型构建思想,构建出虚拟植物生长的结构功能参考模型,并根据植物形态构成及其生长规律,对虚拟植物生长的形态拓扑结构变化进行了定量化描述。2)建立芦苇的发育模拟模型。分析了北固山湿地自然条件及其优势种群芦苇的生长特性,采用生长度日法建立了芦苇发育模拟模型,确定了芦苇在各生育阶段的生长度日参数。3)研究了芦苇的形态发生模拟模型与生理功能模拟模型。在形态发生模型方面,依次建立了芦苇的茎高变化动态模型、芦苇的节间个数变化动态模型、叶面积指数变化动态模型;在生理功能模型方面,建立了芦苇的光合生产动态模型,并采用分配指数的方法建立芦苇的干物质分配模型,克服了分配系数在建立植株干物质分配模型时因不同水肥条件、试验取样差异等造成的较大误差,使得干物质分配的动态模拟具有较好的解释性和预测性。对当年人工移栽芦苇进行了生长动态模拟,与原生芦苇生长进行了比较。4)基于生长机建立芦苇的虚拟植物模拟模型。对芦苇植株的形态结构与生理学特性进行了相关假定,提出器官获取强度、器官扩展分布率和扩展分布函数、同化物的初分配和再分配等概念,建立了植株拓扑结构与累积生长度日的关系模型。在现有的同化物分配理论基础上,提出了同化物的再分配方法,并建立了器官获取强度大小与器官干物质分配指数的对应关系,确立了植株生长年龄为i时不同位置处的同类器官所获得的同化物模型,有机地将同化物的生产和分配过程融为一体。根据模型各参数特点,采用非线性函数参数的最小二乘估算法确定了各器官扩展分布率函数参数。在同化物再分配模型基础上,建立了植株的叶片、叶鞘、节间等器官的形态模拟模型,并对相关参数进行了分析和确定。利用2006年试验观测数据对所构建的模型进行了验证分析,结果表明模型达到一定的可靠性和准确性。5)研究了虚拟植物生长的可视化模型。在所构建的虚拟植物模型基础上,利用可视化技术,建立了虚拟植物生长的可视化模型。采用结构体形式有效地组织了构造单元、叶片、叶鞘、节间等对象包含的数据信息。提出植株拓扑结构信息图形化算法流程,并给出了构造单元的图形化方法。6)建立虚拟植物生长模拟系统,并对系统进行了应用。以Visual C++作为开发工具,结合开放式图形开发工具包OpenGL中的各图形函数模块功能,开发了一个参数化虚拟植物生长原型系统,利用该系统对湿地芦苇生长进行了预测与可视化模拟,验证了模型及相关算法的有效性和可行性。对影响系统模拟结果的参数进行了敏感性分析,并给出了这些参数的试验确定方法。更多还原

【Abstract】 It is a key issue for constructing virtual plant model conforming to the developmental rule of botany to consider simultaneously the change of morphology and physiology,which can also extend the application area in modern agriculture production.The dissertation develops the growth simulation model of dominant plant reed in beigu mountain after doing lots of experiments,and the corresponding virtual plant simulation model as well as its visual model are also founded.Through developing a virtual plant growth simulation system with parameters,it can perform the simulation of reed growth process with various parameters,which will offer theoretic and technologic bases in analyzing or predicting the wetland reed developmental conditions with visualization method.The main research works in the paper are as follows:1. Introducing a consulting model of structure and function for virtual plant growth. According to the construction method of functional-structural model of virtual plant, the author proposes a consulting model of structure and function for virtual plant growth,and elaborates the change of morphological topology architecture of virtual plant growth quantitively based on the plant morphological architecture and its growing law.2. Constructing the developmental simulation model of reed.After analyzing the natural conditions of beigu mountain wetland and the developmental characteristics of its dominant plant reed,it constructs the developmental simulation model of reed with the method of growing degree day,and the growing degree day parameters are also calculated in every developmental stage.3. Studying the morphological and physiological simulation model. For morphological architecture model,it constructs the dynamic model of reed stem change and internode number change as well as leaf area index change;For physiological function model,it constructs the dynamic model of reed photosynthesis,and the reed dry matter allocation model is founded using allocating index method,which can replace allocating coefficient method that usually causes much variation in constructing dry matter allocation model under different water fertilization condition or various experimental specimen,the model is also demonstrated better explanation and prediction in the dynamic simulation of dry matter allocation.Additionally,it simulates the growth of man-planted reed in the paper,and compares the developmental process of man-planted reed with that of the crude reed.4. Constructing virtual plant simulation model of reed based on growth mechanism.On the assumption of reed morphological architecture and physiological characteristics,the author offers some concepts such as organ acquiring strength、organ expansion distribution rate and expansion distribution function、first-allocation and second-allocation of assimilate.The correlationship between plant topology architecture and accumulative growing degree day is founded. On the basis of the existing allocation theory of assimilate,the way of second-allocation of assimilate is introduced,and the corresponding relationship between the organ acquiring strength and the allocating index of dry matter is also constructed.Additionally,the model of dry matter acquired by the same organs at different places when the plant growth age is i years old,which effectively connects the production with the allocation of assimilateAccording to the character of model parameters, parameters of the expansion distribution rate function of organs are calculated by adopting the least square estimation method of nonlinear function parameter.Based on the presented model of second-allocation of assimilate,models of geometric architecture simulation of organs such as leaf and petiole as well as internode are constructed,and the related parameters are also analyzed or calculated.The presented models are proved to be true and feasible to some extent through the experimental data from the year 2006.5. Studying on the visualization model of virtual plant growth. Based on the constructed virtual plant model,the visualization model of virtual plant growth is founded adopting the visualization technology.The information included in the objects such as leaf、petiole and internode in addition to structural unit is organized effectively in terms of structural object.Furthermore,the algorithm of graphic information of plant topology structure is presented,and the graphic method of structural unit is introduced.6. Constructing the virtual plant growth simulation system which is also applied in practice.The dissertation uses Visual C++ as programming tool,connected with the function of related graphic modules of the open graphic tool library,develops a prototype system with parameters of virtual plant growth.In the end,it predicts and simulates visually the wetland reed growth process using the system,which proves the presented models and related algorithms effective and feasible.In addition,the dissertation analyzes the sensitivity of parameters which can affect the simulated results,the methods through experimental determination of these parameters are also introduced.更多还原