Hyperspectral data detect climate impact on tundra vegetation

Sensitive Arctic and Subarctic tundra vegetation is being impacted by the extreme climate changes now influencing much of the Arctic.

Increased temperatures, change in season length, and altered precipitation patterns affect plant health, biomass, and species composition.

In som areas, tundra vegetation responds by spreading is niche or increasing in biomass (greening), while in other areas the vegetation may be damaged or die (browning). Satellite data are used to observe changes in tundra vegetation over the Arctic.

In this decade, several “hyperspectral” satellites will be launched, which provide a continuum of spectral data, providing more detailed insight in vegetation’s biochemical and biophysical properties.

Specific wavelengths have high correlations with vegetation content of nitrogen, anthocyanin, lignin, and leaf-water content, which can be affected by drought and warming.The recently launched EnMAP hyperspectral satellite has 242 narrow wavelength bands and will be used in this project, focussing on tundra vegetation in Sweden affected by drier and warmer conditions.

The aim of this project is to investigate how hyperspectral satellite data can provide new insights into the biochemical and biophysical changes that occur due to climate pressures on Sweden’s sensitive tundra vegetation. The two study areas are tundra sites in Sweden with known browning and greening.

This project will address the following research questions:Can biochemical and biophysical properties of tundra vegetation associated with a drier and warmer climate be detected using EnMAP?Can EnMAP detect tundra plant biodiversity and can hyperspectral data be applied to observe the effect of climate pressures on biodiversity?Is monitoring of tundra vegetation under climate pressure improved by synergistic use of hyperspectral EnMAP data and the higher spatial detail of Sentinel-2 data?The novel aspects are 1) application of EnMAP to observe Arctic browning, 2) a multi-scale, multi-sensor investigation of EnMAP data in combination with Sentinel-2 and hyperspectral drone data for monitoring tundra vegetation, and 3) potential applications for societal actors.

For example, the project work would benefit societal actors such as the Environmental Protection Agency, Sami reindeer herders, and Swedish Civil Contingencies Agency (MSB) working with fire danger and biodiversity monitoring.

The work will be carried out in a four-year PhD project, resulting in four scientific articles, and provide maps of biochemical and biophysical parameters over the study areas.

Given the future abundance of hyperspectral data for the EO community, it is important to learn more about the application of these data now.