AUT University and Auckland Museum have launched a National Spectral Library, to support remote identification of plants and large-scale mapping of plant species.
The online database records plants’ unique spectral light signatures, and will include native and endemic species as well as weed species. The library will be a valuable tool for remote sensing validation, and will soon be available for public access.
So what is a spectral signature? Different plants reflect light in a unique way, depending on factors such as the shape, size and orientation of their leaves, their chlorophyll level, the presence of other chemicals in their cells, and the cell arrangement and airspaces in the plant’s leaves. These factors give a plant’s light reflection distinctive characteristics – creating a signature that can be used in the identification and verification of plants, akin to fingerprinting.
In an article published on Tuesday, the New Zealand Herald highlighted the significance of the National Spectral Library in assessing change in our environment. Read more here: How drones are helping conservation.
AUT’s Programme Leader of Geospatial Sciences, Dr Barbara Bollard-Breen, says the spectral library and Unmanned Aerial Vehicles (UAVs) used in conjunction will be a powerful combination.
UAVs are increasingly being used to capture high quality footage that satellites are unable to deliver; cross-referencing this data against the National Spectral Library will enable accurate verification of the plant species they map from above.
“With lots of cloud cover in New Zealand, visibility can be a problem with satellite footage; with UAVs flying at a much lower altitude than satellites, we can get clear images more of the time,” says Dr Bollard-Breen. “The UAVs take still shots every 1-2 seconds...the images are then stitched together using specialist software, creating an aerial mosaic of the area and enabling us to analyse the ecosystem we’ve surveyed.”
Associate Professor Len Gillman, Head of AUT’s School of Applied Sciences, sees the launch of the National Spectral Library as a positive step forward for conservation research in New Zealand.
“I’m delighted that the National Spectral Library has come to fruition, after much planning and collaboration. It fulfils a shared vision to support advanced conservation efforts, protection of New Zealand’s landscape and the safeguarding of our agriculture sector, and is a vital tool for New Zealand scientists,” he says.