【作者】 李春友；

【导师】 孟平；

【作者基本信息】 中国林业科学研究院 ， 生态学， 2012， 博士

【摘要】 农林复合系统在解决农林用地矛盾、改善生态环境、提高自然资源利用效率、促进农村经济发展等方面具有重要的实践价值。林木冠层动态模拟技术系统对科学预测复合系统结构，进一步开展功能与效应的预测评价，提高复合系统调控管理成效具有重要技术支撑作用。同时对比野外试验研究，模拟实验能节约人力、物力和财力，提高研究水平和工作效率。核桃-作物/药草间作系统是华北石质山地重要的土地利用方式，也是当地退耕还林生态工程的主要模式之一，核桃复合经营系统林木冠层结构的动态模拟研究具有很好的代表性和实践应用性，有利于浅山丘陵地区不同类型脆弱生态区的经济和生态协调发展。在地处河南省济源市的黄河小浪底森林生态系统定位研究站的核桃试验地，自2008到2011年，通过核桃的生长发育观测和冠层几何结构观测，针对林木几何结构的相关田间实测技术及模型在形态学参数提取不易及时空分辨率不足等方面问题，从冠层几何结构的三维形态特征参数测算和几何形态模拟两个技术关键入手，以生育期为时间尺度，基于大量实测数据，综合采用数理统计、分形理论及计算机可视化技术等理论和方法，对核桃复合系统结构进行了田间试验和数值模拟试验，主要结果包括以下几个方面：（1）应用多基线近景摄影测量技术，形成了包括植株三维坐标，以及植株主干高和胸径、侧枝长和基径、侧枝生长倾斜角度和伸展方位等冠层几何结构参数等方面测算在内的树木三维几何形态测量技术，为林木虚拟植物的实现提供了廉价而实用的林木几何形态数据和参数获取技术。该方法的测量及精度基础是植株各部位的三维坐标测定，分析表明：X坐标的绝对误差0.000m~0.023m，平均为0.006m，相对误差0.000%~0.162%，平均为0.042%；Y坐标的绝对误差0.001m~0.032m，平均为0.006m，相对误差0.007%~0.240%，平均为0.047%；Z坐标的绝对误差0.000m~0.031m，平均为0.002m，相对误差0.000%~0.269%，平均为0.020%。测量精度完全满足了植物冠层几何结构数值表达的精度要求。（2）建立了基于有效发育日数概念的核桃发育的物候期模拟模型，构建了基于Logstic方程的核桃株高、主干粗生长、侧枝的粗生长和高（长）生长等模拟模型，以及双圆曲线叶片形状模型及叶片发育模型，为虚拟植物三维几何形态构成提供了基本参数和基础数据。对比2011年物候期观测资料，物候期模拟模型在整个生长季的物候期绝对误差2~4天、相对误差0.0%~1.2%。对比2011年15株核桃树高和胸径观测资料，树高模拟的绝对误差0.8cm~61.8cm，平均为27.6cm，相对误差0.2%~14.1%，平均为5.5%；胸径模拟的绝对误差0.1cm~3.2cm，平均为1.4cm，相对误差0.4%~24.5%，平均为11.4%。15株核桃平均树高505.5cm、平均胸径12.7cm，树高绝对误差和相对误差分别为4.7cm和0.9%，胸径绝对误差和相对误差分别为0.3cm和2.4%。对比7个复叶（共59片小叶）的实测数据，单片小叶面积模拟的绝对误差0.0cm2~14.9cm~2，平均为2.2cm~2，相对误差0.2%~11.9%，平均为3.8%。（3）基于核桃几何形态生长发育模型的模拟结果，采用基于L-系统分形技术的虚拟植物模拟方法和OpenGL的三维可视化技术，建立了林木单植株生长的可视化动态模拟模型。在单植株模型基础上，通过分级分层实现、枝条大小和伸展角度变化、叶片角度和颜色深浅变化、矢量角计算等途径实现多行植株模拟，构建了林分尺度的、“四维”动态的虚拟植物模型。模型采用模块化开发方法，在枝、叶等几何形态特征生长参数方面均有相应输入接口，同时实现了数量化植物生长模型和图形化植株几何形态的表达，为今后模型系统的进一步完善奠定了良好的基础。（4）基于叶片形状模型，以像素为计算单元，采用几何图形的布尔加和运算法则、蒙特卡罗概率方法模拟了单株和林分尺度的冠层透光特征。模拟值误差分析显示，核桃林冠下地面处的透光率实测值和模拟值的相对误差平均为15%。说明辐射模拟模式基本具备了定量描述农林复合系统中太阳辐射传输规律的动态预测功能，可为核桃-作物/药草间作系统配置模式提供辐射数据支持；同时也表明模型有待进一步改进和完善。（5）基于冠层辐射传输的数值模拟数据，结合决明子、绿豆、红小豆、小辣椒、花生等当地常见经济作物及药用植物的温光特性，提出核桃-经济作物、核桃-药草复合系统合理经营年限、空间结构配置方案，为不同核桃树龄条件下农林复合系统的结构调控与优化、可持续经营管理提供了重要的指导作用；同时，也为今后相应间作系统作物共生期生长发育模拟试验奠定了基础。上述研究成果经过不断完善，将具有很强的实用性，在农林复合系统经营实践中具有广泛的应用前景，可为生态兴国战略的实施提供重要的技术支撑。然而，由于研究实际年限只有4年，研究工作仅集中于林木生长发育期的部分阶段，这对于核桃等生长周期较长的果树而言显然不足，更进一步研究成果的获得尚需要长期的定位研究，尤其是要加强农林复合系统中林木几何形态特征参数动态变化与光照、温度、水分等环境因子之间相互作用的长期定量化研究。更多还原

【Abstract】 Agroforestry system has important value in the practice of resolving the contradictions ofagricultural and forest land use, improving the ecological environment and the use efficiency ofnatural resources, promoting the rural economic development. Dynamic simulation technologysystems of fruit tree canopy were constructed in the fruit-crop intercropping system. Thistechnology system has important technological support roles in forecasting the structure ofagroforestry system scientifically, further studying on prediction and evaluation of the functionand effect for agroforestry system, and increasing the efficiency of regulation and managementfor agroforestry system. Compared to experimental research and treatment on field, applicationof this technology system can also reduce expend of manpower and material resources andincrease research level and efficiency to some extent. The walnut-crops/herb intercroppingsystem is important land-use way, and is also one of main pattern for reafforestation projects.The dynamic simulation research of tree canopy structure in agroforestry system with walnuthas well typical and practical application. Application of the research results can be beneficialto the harmonious development of economy and ecology in different types of fragile ecotope ofthe low hilly areas.The observation experiment of field for walnut(Juglans regia) growth and canopygeometric structure were done in walnut experimental plot of Xiaolangdi Forest EcosystemResearch Station of the Yellow River which located in Jiyuan, Henan province during2008-2011. As the extraction of morphological parameter was very complicated and spatial andtemporal resolution was low in relative field measure technology and model of tree geometrystructure, two key technologies including three dimensional morphological character parametermeasurement and geometry simulation of canopy geometric structure were adopted. Takinggrowth phase as time dimension, theories and methods containing mathematics, fractal theoryas well as computer visualization technology were synthesized, and field experiment and numerical simulation test were constructed in the agroforestry system based on a great deal ofmeasured data. The main results are as follows:(1) A multi-baseline close-range photogrammetry technology to establish the3D geometrymeasurement technology in trees was adopted. The technology was based on estimates ofcanopy geometrical parameters, which involving in measurement of plant three-dimensionalcoordinates; estimates of the plant height and brest diameter of trunk, length, basal diameter,growth tilt angle and stretch direction of lateral branch. This technology offered a cheap andpractical technology of obtaining forest geometry data and character parameters for therealization of the forest virtual plant.The measurement and its accuracy of this method was based on the measuring precisionof three-dimensional coordinate for walnut plant. The case analysis showed that the absoluteerror of X-coordinate was0.000-0.023m, and0.006m for the averaged value, the relative errorwas0.000%-0.162%,0.042%for the averaged value; the absolute error of Y-coordinate was0.001-0.032m, and0.006m for the averaged value, the relative error was0.007%-0.240%,0.047%for the averaged value; the absolute error of Z-coordinate was0.000-0.031m, and0.002m for the averaged value, the relative error was0.000%-0.269%,0.020%for theaveraged value. The measuring precision fully met the requirements of quantitative expressionfor plant canopy geometric strcture.(2) A simulation model of walnut phonological development based on the concept of daynumber of effective development was established; and simulation models of growth withwalnut plant height, trunk thick, lateral branch length and height, and the model of leaf shapeand leaf growth were established. Establishment of these models provides the basic parametersand data of three-dimensional geometry for the virtual plan.Compared to the observation data of walnut phonological development in2011, theabsolute error of simulation value of phonological model in whole growth season was2-4day,the relative error was0.0%-1.2%.Compared to the observation data of tree height and brest diameter for15walnut plants in2011, the absolute error of simulation value for tree height was0.8-61.8cm and the average was27.6cm, the relative error was0.2%-14.1%and the average was5.5%; the absolute errorof simulation value for tree brest was0.1cm-3.2cm and the average was1.4cm, the relativeerror was0.4%-24.5%and the average was11.4%. On average for15plants, the tree heightwas505.5cm and the brest diameter was12.7cm, the absolute and relative error for tree heightwas respectively4.7cm and0.9%, the absolute and relative error for brest diameter wasrespectively0.3cm and2.4%.Compared to the measured data for59leaflets of7compound leaves, the absolute error ofsimulation value for the single leaflet was0.0-14.9cm2, the average was2.2cm2, the relativeerror was0.2%-11.9%, the average was3.8%.(3) Based on the OpenGL3D visualization technology and L-system Fractal Technologywith Virtual plant simulation capability, a visualization model of dynamically simulatingwalnut’s single plant growth was established.On the basis of establishing a single plant model, a stand scale, four-dimensional virtualplant growth model was constructed. This model used leveled and layered implementation,changing of the size and stretching angle for lateral branches, changing of blade angle andcolor shades, a vector angle calculation to achieve multi-row plant simulation.These models were developed with modularization. Model in terms of growth parameterswith branches and leaves had the corresponding input interface, while achieving the expressionof quantification of plant growth models and graphical plant geometry. It laid a goodfoundation to further improve the model system.(4) Based on blade shape and the Monte Carlo probability method with pixel as thecalculated cell, the Boolean algorithms of geometry was adopted to simulate the canopy lighttransmission characteristics in single-plant and stand scale respectively. The error analysis forsimulation value of canopy transmittance showed that the relative error was15%. Thesimulation model basically had the quantitative description function of the dynamic predictionof solar radiation transfer law in the agroforestry systems. Model could providewalnut-crops/herb intercropping system with the support of the radiation data. Furtherimproving of these models was anticipated. (5) The reasonable intercropping years and spatial configuration for agroforestry systemsuch as walnut-cash crops and walnut-herb were suggested, which being based on thesimulation result of canopy radiation transfer for walnut in walnut-crop/herb intercroppingsystems, combining with temperature and photoperiod characteristic of cash crops andmedicinal plants which being local and common such as cassia(Catsia tora Linn),mung-bean(Vigna radiata), red bean(Vigna angularis), capsicum(Capsicum frutescens) andpeanut（Arachis hypogaea）. These suggestion could provide important instructive effect forstructure control and regulation as well as sustainable management of agroforestry system atdifferent age of fruit tree. Meantime, the above research also established a basis for simulationexperiment of growth and development of intercropping crop in the co-growth period in thefuture.The above results will have extensive application foreground in the management practiceof agroforestry system after gradual improvement, and can provide important technologicalsupport for the implement of national ecology strategy. Whereas, the actual research time isonly4years, and researches only has focused on part of the tree growth periods, which isobviously insufficient for growth and development simulation of fruits like walnut which has arelative long growth cycle. Therefore, acquirement of further research results need long-termlocation study, and long-term quantitative study of the interaction between the dynamic changeof tree geometry character parameter and environments such as light, temperature and water inagroforestry system should be enhanced especially.更多还原