Did you know that the Arctic and Subarctic landscapes are filled with lakes and ponds that play a crucial role in the planet’s balance? These water bodies help regulate the climate, support biodiversity, and influence greenhouse gas emissions. They act like natural sensors, indicating how permafrost degradation is transforming the landscape. 

As we mentioned in November, a team of researchers developed a groundbreaking tool called HLWATER V1.0, capable of automatically identifying these lakes. The study centred on the Nunavik region in Subarctic Canada, a stunning landscape where tundra meets boreal forest, forming an extensive network of water bodies, from glacial lakes to peatland ponds. 

But what comes next? What new discoveries have they made? Identifying these lakes is insufficient. It is essential to study them and understand their characteristics and spatial patterns, and that’s precisely what the team concentrated on in this new scientific paper. This time, the team examined three key parameters of the lakes: limnicity (size), limnodensity (quantity), and limnodiversity (optical diversity or colours, an important indicator of their chemical composition). 

And what did they find? Of the more than 335,000 lakes in this region, 90% are smaller than 0.01 km², meaning they are tiny. The larger lakes are found in glacial depressions on rocky outcrops. The highest limnodiversity occurs on valley slopes, where silt-clay deposits dominate and where permafrost degradation is most intense. Additionally, this is where we see the greatest limnodiversity, with black and brown lakes, rich in organic matter, and light brown or even white lakes, where mineral sediments predominate. 

Although these landscapes cover only 2 to 7% of the region, they contain more than 1/3 of all water bodies. And why is this important? Unfortunately, these lakes are not just beautiful; they release greenhouse gases, influence the climate, and impact the entire planet. 

Now that we can map and analyze these lakes with greater precision, can we predict how they will change in the future? Science continues to investigate!

Source: Freitas, P., Vieira, G., Martins, D., Canário, J., Pina, P., Heim, B., … Vincent, W. F. (2024). Diversity of lakes and ponds in the forest-tundra ecozone: from limnicity to limnodiversity. GIScience & Remote Sensing, 61(1).

Author: Diana Martins