Exciting progress in remote sensing has seen new satellite technology gather important information on the kinds of habitat structures crucial for maintaining biodiversity in forests.
As the impact of humans on the planet escalates, there has been a continual decline in non-human populations and the extinction of an increasing number of species, largely as a consequence of habitat degradation. The resultant negative impact on biodiversity has proven problematic to measure due to the high costs associated with monitoring habitat loss over large areas that are often difficult to access.
However, advances in airborne remote sensing have resulted in the increased use of these technologies for ecological investigations, and their potential for obtaining reliable and ongoing updates on the spatial information required to monitor biodiversity over large areas is now recognised.
Now, research published in Nature communications has uncovered the promising predictive ability of radar-derived data captured by the recently launched, satellite borne system known as Sentinel-1.
The data was used to map the biodiversity of species populations across five temperate forest regions in Central Europe. It was found to be as effective in modelling habitat structure as data acquired by airborne laser scanning (ALS).
To date, ALS has been considered the ‘gold standard’ when it comes to the measurement of forest structures and biodiversity, thanks to its ability to characterise the complex three-dimensional structure of terrain and vegetation.
However, space-borne synthetic aperture radar (SAR) systems, such as those involved with the Sentinel-1 mission, could provide an alternative source for ecologically meaningful information on vegetation structure at regional and global scales.
Another major advantage of SAR is its ability to penetrate clouds, making it suitable for the monitoring of regions that experience near-constant cloud coverage, including tropical and mountainous areas.
The Sentinel-1 mission includes two SAR satellites, launched by the European Space Agency in 2014 and 2016, which have been successful in providing meaningful data due to the technology’s combination of high spatial resolution, ability to revisit locations every five to ten days, and complete geographical coverage of the earth.
Using the data acquired through the Sentinel-1 mission, researchers have now conducted the first evaluation of its potential for successful biodiversity mapping. The study compared data captured through the Sentinel-1 mission with the better-established ALS metrics, and their abilities to form an understanding of habitat structures in forest ecosystems.
As predictors of biodiversity, the two remote-sensing techniques were found to be similar in their effectiveness; the Sentinel-1 data was shown to be superior for estimating species composition, and ALS for species richness. The study therefore demonstrates the future potential of such data for monitoring the biodiversity of forests and other large-scale habitats.
Source: Nature.com
