Boreal forests tend to have a thick layer of organic material but the soil is poor in nutrients. what is the best explanation for this?

Some possible explanation as below

Explanation:

These comprise one third of the circumpolar area that circles the northern hemisphere. It is right that the Boreal forest biome has a thick layer of organic matter but the soil lacks in nutrients as :

The thickness of the soil is largely due to its cold climatic conditions. which hinders the development of a plant that is unable to take up the nutrients.

Also, the boreal forest biome is located at higher altitudes so the planets find it difficult to generate photosynthesis.

Also, large areas of the forest biome have been cleared due to lumbering practices of the Soviet Union and Canadian government which then replace it with motocross.

Another reason can be due to the climate change impact, this zone experiences increasing temperature i.e severe winters and other natural disturbances like forest fires and insects or diseases, etc.