Snow Under Trees for Fabric
Snow Under Trees adds, who would have thought, snow under trees. This will happen whenever new chunks are generated, or when it is snowing. Do note, that only biomes in which it is cold enough to snow are affected. Normal forests for instance will be unaffected. Modded biomes will work.
This mod is a Fabric port of Snow Under Trees (Forge) by bl4ckscor3.

Before and after (GIF):

Mod Requirements:

Configuration options:

You can find the config file (snowundertrees.json5) in the config folder of your .minecraft directory or the main server directory. Make sure you restart your game after updating config values! I suggest taking backups before making changes always.

enable_biome_feature - Setting this to false will disable snow from generating under trees when new chunks are generated.
enable_when_snowing - Setting this to false will disable snow from generating under trees when it is snowing in the world.
filtered_biomes - Any biomes whose biome IDs are added here will not be affected by this mod in any way. You can find the biome ID of the biome you're currently in on the F3 screen. For example, the biome ID of the plains biome looks like this: minecraft:plains.

Credits:
Big thanks to bl4ckscor3 for allowing me to port this mod to fabric! Do show him some love!