激光扫描与涡度测量：三维森林生态系统碳水过程模式

Forest ecosystem process modeling currently is a research hotspot, which serves as both a critical circle in exploring the scientific topics such as primary productivities and terrestrial processes and a core issue in understanding of Earth's surface material migrations and energy flows. However, it suffers from a problem, i.e., inconsistency lies between analysis of carbon and water biochemical processes and characterization of three-dimensional (3D) forest morphologies and structures, and this has seriously blocked the domain of forest ecosystem understanding from moving forward. Aimed at this gap, with the situation of mature forest biochemical process models now still being in shortage in China taken into account, this project will introduce the 3D mapping technology of laser scanning to creatively develop a solution plan. With the two basic biochemical processes (i.e., carbon and water cycles) in forest functioning selected as the processes of interest, the applicant plans to innovatively develop a 3D carbon-water-coupled process model of forest ecosystem by combining eddy-covariance flux measurement and laser scanning. The idea stems from the schematic plan of forest macro-ecology, which can give a new viewpoint to the community traditionally focusing on forest physiological ecology. This facilitates exploring the embedded associations between their external morphological characteristics and internal biochemical driving forces. The two heterogeneous kinds of data collections will be interlinked by improving the traditional large-leaf model to a new multi-leaves model, which is appropriate for characterization of 3D forest processes. Then, the 3D modes of forest ecosystem processes will be explored and a new 3D carbon-water-coupled model will be developed into prototype software for the purpose of simulation and prediction of forest productivity and growth. This project is of high potential for push forwarding the relevant communities in our country to keep pace with the newly-emerging studies on 3D forest ecosystem processes in the world, and the contributions of this study are of fundamental scientific implications for both advancing the contemporary transition of forest understanding from "2D" to "3D" and strengthening the studies on from forest physiological ecology to biogeochemical cycle.

森林生态系统过程模式是当前的研究热点，是探讨初级生产力、陆面过程等科学问题的关键环节，是了解地球表层物质迁移与能量流动等的核心基础问题。然而目前存在碳水生化过程分析与三维形态结构表征不统一的问题，这已严重影响了对于森林生态系统整体认知的推进。针对上述问题，结合国内至今尚无成熟的森林生化过程模型这一基础性缺失，本项目将创新性地引入直接三维测量的激光扫描技术，从其与涡度测量组合的宏观生态系统建模角度切入，跳出常规深究碳、水生理机理的模式而以其表观呈现为抓手，探讨森林外在形态与内在生化驱动的关联，通过改进传统大叶模型至多叶模型等方法，表征森林碳水过程三维耦合模式，开发与森林生长动态内外统一的三维过程模型与原型软件系统，实现与国际上新兴的森林三维过程前沿研究保持同步，推动对森林生态系统的认知由二维到三维的转变，这无论反向对森林生理生态机理研究或正向对生物地球化学循环研究等均具有基础推动意义。

森林生态系统过程模式是当前的研究热点，是探讨初级生产力、陆面过程等科学问题的关键环节。然而目前存在碳水生化过程分析与三维形态结构表征不统一的问题，这已严重影响了对于森林生态系统整体认知的推进。针对上述问题，本项目将创新性地组合激光扫描与涡度测量组合的宏观生态系统建模角度切入，主要研究内容包括：（1）基于激光扫描与涡度测量探讨森林三维形态与冠层表观能量交换的内在决定关系；（2）从系统建模的角度探讨森林外在形态呈现与内在碳水生化过程的三维耦合模式；（3）开发具备三维过程模式分析与生长预测功能的森林三维过程表征模型。.在项目的支持下，我们探索开发了一系列原创性的解决方案和高效算法：（1）基于激光扫描与涡度测量的森林生态系统碳水过程参量化新方案，涵盖表征水过程的水分利用效率遥感参量因子、表征碳过程基础的叶绿素遥感参量因子、表征碳过程呈现的总初级生产力遥感参量因子、以及反映碳水过程决定机制的基础理论重构；（2）针对影响森林生态系统碳水过程的潜在环境因子遥感反演新算法，涵盖可能会影响生态系统碳水过程的物候、陆地表面的偏振反射率、晴空短波气溶胶直接辐射效应、数字地形模型；（3）森林生态系统及更大尺度碳水过程的生态效应模式分析，涵盖分析方法体系的提升、树间生态效应的三维探索、林木空间分布三维模式分析、进而拓展尺度宏观比较生态驱动贡献、在降雪物候表征水过程的同时引入生物多样性表征碳过程并分析它们间的宏观生态作用、进一步落脚于初级生产力表征碳过程并分析它们间的宏观生态驱动机制；（4）支撑森林生态系统碳水过程模式分析的新型遥感技术开发，涵盖低成本移动式的三维植物结构表型、高光谱线性光谱解混的不同约束条件分析、偏振激光雷达对地观测、基于机载LiDAR数据和Landsat8影像的过渡带提取。.项目组共发表SCI期刊论文13篇、中文核刊论文3篇、学术会议论文2篇，培养博士3名、硕士2名，获批软件著作权1项。