Significance of structural complexity
Against the background that future challenges due to climate change
might result in a dramatically increased importance of the buffer or
adaptive capacity of an ecosystem, the above said has important
implications. If it is possible to measure structural complexity of an
ecosystem, one might be able to provide a proxy for its adaptive
capacity. For trees and forests, the quantification of the overall
structural complexity in three-dimensional (3D) space is today possible
based on terrestrial, mobile and airborne 3D laser scanning (Atkins et
al. 2018b, Ehbrecht et al. 2017; 2021, Seidel 2018, Dorji et al. 2021,
Stiers et al. 2020, Willim et al. 2020). Global approaches based on
spaceborne laser scanning from the international space station (ISS) by
means of NASA’s GEDI (global ecosystem dynamics investigation) also
provide tools for an assessment of forest complexity and structure
mapping (e.g. Schneider et al. 2020). With structure and complexity
available, it is equally important to gain information on tree species
identity. Here, large progress has also been made when it comes to
species identification for example from infrared sensors (e.g. Pan et
al. 2022). Silviculturists know ways to increase the complexity of
managed forests (Peck et al. 2014), mimicking natural developments (e.g.
Messier et al. 2013) or admixing additional tree species, resulting in
forests that produce timber but that are almost as complex as primary
forests at the same time (e.g. Stiers et al. 2020). Figure 1 provides a
visual representation of the theoretical ideas present here.