Mountains and oceans also affect the temperature of land nearby. The poles are the coldest areas, while mountains at the equator, if they are high enough, may be covered with snowy tops. Annual amount of precipitation is also influenced by mountains and bodies of water. Equatorial regions are humid and have heavy rainfall throughout the year. Desert regions have almost no rain at all.
Temperate regions have abundant rainfall, hot summers and cold winters.
Soil is composed of organic and inorganic materials. Rock particles are broken off from larger rocks by weathering. The freezing and thawing helps to crack and break the rocks. Bacteria, fungi, lichens and other soil-formers break down rocks. Dead plants furnish organic matter for soil.