Satellite remote sensing delivers ecologically relevant data for assess changes in ecosystem through ecosystem risk assessment protocols.
An accurate map is essential when assessing an ecosystem. Satellite remote sensing has spatial and temporal resolution fine enough to represent ecosystem dynamics and can help deliver these maps, so it has become an important tool, not just for the IUCN Red List of Ecosystems (RLE), but for ecologists and conservationists alike.
Satellites provide global coverage of our planet (allowing us to gather information in areas which would otherwise be impossible to reach). They also gather information continually over time as they orbit our planet, and the open-access nature of satellite imagery provided by national space agencies (e.g. Landsat data provided by USGS and Sentinel data provided by ESA), coupled with the recent development of online application tools such as REMAP, has helped both expert researchers and users with little background knowledge in remote sensing to access and take advantage of satellite data.
Ecosystems risk assessments typically require information on the geographic distribution of an ecosystem, changes in spatial extent, and changes in ecosystem function over time. The IUCN Red List of Ecosystems (RLE), in particular, uses satellite-derived information to assess ecosystem risk of collapse by measuring different aspects of a targeted ecosystem:
- Criteria A considers the decline rate of area of an ecosystem, allocating risk categories based on how quickly the ecosystem is shrinking.
- Criteria B instead looks at the spatial distribution, with a higher risk category given to ecosystems which can potentially be threatened by large catastrophic events.
- Criteria C and D also require the distribution of the ecosystem to accurately calculate the relative severity of environmental degradation or disruption to biotic processes.
Lastly, we must remember that satellites can provide us with more than accurate maps. We can also use satellite-derived information to inform us on ecosystem condition, using various indices such as the Normalised Difference Vegetation Index (NDVI), Normalised Difference Water Index (NDWI), Normalised Difference Moisture Index (NDMI) etc. This information allows us to move from simply mapping the extent of an ecosystem, towards monitoring its condition and using this information to assess its risk of collapse.
As it develops further and overcomes its limitations, this technology will greatly enhance our ability to assess ecosystem risks - effectively speeding up our capacity to formulate and introduce necessary environmental and conservation policies.
For further reading you can find the paper The role of satellite remote sensing in structured ecosystem risk assessments (Murray et al. 2018) in our Research and development section.
Written by: Calvin Lee
Style and format: Lila Garcia and Clara Gómez
Provita Jul 25, 2019