The things with winter and overnight freeze are that this change of the weather can seriously harm the crop and do irreversible damage.
To prevent this, farmers use some methods.
One is the usage of heaters, not allowing the freeze to set.
Another one is to spray the crop with water before the predicted overnight freeze. When water freezes and turns into ice, it releases latent heat. Then, the ice that builds upon the plant will insulate it from the colder surrounding air temperatures.
My guess would have to be hydropower, since water isn't an un natural substance
Water erosion is usually what people think of, but ice, wind and gravity can also cause erosion.
Water erosion is usually along rivers. As the water moves quickly by it rubs on the rock and dirt, causing rivers to slowly get wider.
Ice erosion is caused by glaciers. Sometimes it's a glacier rubbing against land, and there's a lake that was made by a glacier making it's way onto land and then melting.
Wind erosion is a big problem in fields and large open plains with loose dirt. The wind just blows all the dirt away.
Gravity can cause erosion and cliffs. Sometimes along a mountain or cliff the rock won't be able to hold itself up anymore, and gravity will pull it down.
Your answer would be all of them. Wind, water, ice, and gravity.
A genotype is determined by your genes and a phenotype is by your physical features