REMOTE DETECTION AND MONITORING OF PLANT TRAITS: THEORY AND PRACTICE

A means for tracking global plant biodiversity and understanding ecological processes is to identify general functioning principles and quantify underpinning common traits across species. Cumulative knowledge from applied spectroscopy in plant functioning has demonstrated the use of hyperspectral remote sensing in quantifying leaf and canopy biochemical and physiological traits. This article aims to provide an overview of the existing theory, research, and applications of remote sensing of plant functioning traits and wraps up future directions and challenges for ecologists and remote sensing users in assessing global biodiversity and ecological functions. It covers the physics, chemistry, and physiological ecology underlying the relationships between leaf and canopy optical properties with functional traits. Within the scope of the article, descriptions and commonly used physical and empirical trait retrieval approaches are included for both leaf and canopy scales. The last section considers the advancing of retrieving frameworks through emerging hyperspectral remote sensing technology and data-driven analytics. The article concludes by calling for a greater infusion of biological and ecological principles into remote trait retrieval techniques to ultimately improve understanding of ecosystem function and dynamics across different spatial and temporal scenarios.