a small leaf pile will destroy the grass underneath it quickly, but an even thicker snow pile that lasts for months throughout the winter seems to have no effect. Why?

Question

Editing just to say thanks to everyone who has contributed. The responses make perfect sense!

In: Biology

Answer 1

A few things,

In cold temps, plants go into hibernation mode. It uses the energy it stored up to ride out the covering of snow.

Also leaves are highly acidic. To many in a given area will change the properties of the soil.

Finally, is the leaf still living?
Fresh leaves still absorb sunlight, even off the tree!