Conclusions
This review has examined the remote sensing of grassland biodiversity
and functional traits with a focus on recent technological and
methodological developments. Advances in UAV technology have accelerated
the increase in grasslands surveys featuring very high spatial
resolutions, with 3D components and increasingly employing multispectral
and hyperspectral sensors. As UAV technology continues to improve and
become more accessible through cheaper costs and automated flight
controls, and survey and processing methods mature, UAVs are likely to
become a standard tool in grassland surveys. UAV surveys can also bridge
the gap between ground-based fieldwork and satellite remote sensing, as
well as providing ground truthing for spaceborne data, potentially
refining the seemingly inconsistent relationship between spectra
variation and biodiversity. This can aid in the development of satellite
remote sensing methods and allow the scaling of biodiversity and
functional trait surveys from discrete points to site-wide and national
surveys.