This is about a scree slope near Ticino -

The scree acts like a chimney during the cold winter periods. Warm and light air is expelled out of the upper part of the scree and is replaced by cold and dense air aspirated inside the lower part of the slope. The process leads to the overcooling of the scree in winter and to the occurrence of permafrost

In summer, the chimney effect is reverse and the permanent expiration of cold air prevents the vegetation from growing normally.

https://www.arlis.org/docs/vol1/ICOP/55700698/Pdf/Chapter_03...