Tree Species Diversity Mapping—Success Stories and Possible Ways Forward

The special issue “Tree species diversity mapping” presents research focused on the remote assessment of tree diversity, using different sensor modalities and platforms. thereby recognizes that continued loss biodiversity poses a great challenge to humanity. Precise regularly updated baseline information is urgently needed, which difficult, field inventories, especially large scale. On such scales, sensing methods excel. work presented in demonstrates potential Earth Observation (EO) for addressing knowledge gaps, as EO provides rich (spectral) at high revisit frequencies spatial resolutions. Many can be distinguished well optical data, particular, when simultaneously leveraging both spectral temporal dimensions. A combination with other further improve performance. approaches are, however, limited by availability high-quality reference information. This complicates task collection data labor time-consuming. To mitigate this limiting factor, resources should better shared amongst community. reliance situ also highlights need focus extraction more permanent (i.e., species-inherent) properties. In respect, we identify discuss some inherent limitations current regarding discrimination. end, offer fundamental view classification based physical principles. provide summary stimulating thoughts about possible future directions, structured present communication into four parts. We first introduce information, followed all 19 articles published within issue. are ordered number investigated. Next, short main outputs. stimulate discussion scientific community, conclude offering its biophysical foundations. purport possibly robustly identified if classify/identify them feature space not spectral-temporal space. involves creation inversion so-called physically-based radiative transfer models (RTM), take hyper/multispectral observations together their observation geometry (as priors), project these variables chlorophyll content LAI etc. perceived advantage an approach generalizability (and scalability) classifications will increase, trajectory parameter probably robust compared sole analysis which—amongst perturbing factors—also depend site/time specific illumination geometry.