Current Trends in Forest Ecological Applications of Three-Dimensional Remote Sensing: Transition from Experimental to Operational Solutions?

Abstract

The alarming increase in the magnitude and spatiotemporal patterns of changes in composition, structure and function of forest ecosystems during recent years calls for enhanced cross-border mitigation and adaption measures, which strongly entail intensified research to understand the underlying processes in the ecosystems as well as their dynamics. Remote sensing data and methods are nowadays the main complementary sources of synoptic, up-to-date and objective information to support field observations in forest ecology. In particular, analysis of three-dimensional (3D) remote sensing data is regarded as an appropriate complement, since they are hypothesized to resemble the 3D character of most forest attributes. Following their use in various small-scale forest structural analyses over the past two decades, these sources of data are now on their way to be integrated in novel applications in fields like citizen science, environmental impact assessment, forest fire analysis, and biodiversity assessment in remote areas. These and a number of other novel applications provide valuable material for the Forests special issue “3D Remote Sensing Applications in Forest Ecology: Composition, Structure and Function”, which shows the promising future of these technologies and improves our understanding of the potentials and challenges of 3D remote sensing in practical forest ecology worldwide.

Towards complex applications of active remote sensing for ecology and conservation

“…Along with the general trends described, specific trends were observed in the published contributions that show an emerging transition from rather indirect and solely proxy-based usage of active remote sensing derivatives towards more complex applications, that is, direct estimation of ecological metrics at multiple spatial scales, as was envisioned by Almeida et al (2019), Latifi and Valbuena (2019) and Valbuena et al (2020). We posit this to be driven by the constantly increasing accessibility and reduced cost-performance ratio of active data sources from terrestrial to spaceborne platforms.…”

“…Examples include mutual effects of vegetation structure and fauna (Coverdale & Davies, 2023), wildfire disturbances and their interaction with habitat structure (Singh et al, 2023), and optimizing sample size or sampling grids for measurement of reference ecological data (Knott et al, 2023). Indeed, almost all the themes previously mentioned by Latifi and Valbuena (2019) as shaping the future research of 3D remote sensing (the majority of which being active data sources) were among the submissions to this cross‐journal Special Feature. The geographical distribution of the studies is presented in Figure 2. Figure 3 summarizes the keywords of the entire studies in a word cloud.…”

“…The indirect, proxy‐based methods for use in ecology and conservation practice were thoroughly reviewed by Simonson et al (2014). However, the ongoing shift from indirect (implying less complex data processing) to direct (implying complex data processing) application, presented initially in the context of 3D remote sensing by Almeida et al (2019), Latifi and Valbuena (2019), and Valbuena et al (2020), is illustrated in the articles in this Special Feature. Examples include mutual effects of vegetation structure and fauna (Coverdale & Davies, 2023), wildfire disturbances and their interaction with habitat structure (Singh et al, 2023), and optimizing sample size or sampling grids for measurement of reference ecological data (Knott et al, 2023).…”

“…Indeed, almost all the themes previously mentioned by Latifi and Valbuena (2019) as shaping the future research of 3D remote sensing (the majority of which being active data sources) were among the submissions to this cross-journal Special Feature.…”

Integrating forest structural diversity measurement into ecological research

“…There is a clear need to understand how spatial grain and extent factor into FSD measurement. FSD measurements that capture spatial and temporal change in forest structure are needed to track changes in structural diversity equivalent to alpha, beta, and gamma diversity (Fotis, Morin, et al, 2018; Fotis, Murphy, et al, 2018; Latifi & Valbuena, 2019). It is also necessary to invest efforts in the identification, classification, and detection of attributes of structural diversity that are rare, uncommon, or critically important, but difficult to measure as well as the development of indices that are sensitive to changes of such rare structural features.…”