Research Progress on Non-Destructive Detection of Ancient and Famous Trees

Ancient and famous trees are non-renewable natural and cultural heritages, and the accurate diagnosis of health status is crucial for their conservation and management. Over the past two decades, the non-destructive testing technical system centering on stress wave tomography, ground penetrating radar (GPR), LiDAR simultaneous localization and mapping (SLAM), thermal dissipation sap flow measurement (TDP) and portable photosynthesis measurement has been gradually established, which has realized the multi-dimensional non-destructive evaluation covering internal trunk structure, spatial distribution of root systems, three-dimensional phenotypic morphology, as well as water physiology and carbon assimilation capacity. This paper systematically reviews the principles, research progress, detection accuracy and current application status of the above technologies in health monitoring of ancient and famous trees, summarizes key parameters and quantitative evaluation indices, analyzes the application framework of multimodal technology fusion in comprehensive health assessment of ancient trees, and discusses the current application bottlenecks and future development directions.