Climate is a desert's defining characteristic, and it is an excellent starting place for lessons on the region. Deserts receive less than 10 inches of precipitation a year. This lack of moisture has a direct influence on the type of vegetation and wildlife in the areas. Lessons can focus on deserts' temperature contrast between night and day because of their inability to block sunlight with clouds or trap heat at night with humidity. Lessons can also touch on how even cold, dry locations like Antarctica are still deserts even though they get their precipitation in the form of snow.
Deserts only form in specific regions, often because of key nearby land formations. Lessons therefore should encapsulate how these land formations create deserts' dry terrain. A lesson could discuss the way mountains block the path of precipitation, forcing air to rise over top and release rainfall along the wind-facing slopes of the mountains. The dry air that descends down the other side is rarely able to form clouds.
Despite their reputation for being desolate wastelands, deserts support a large amount of plant life. Cacti and shrubs are the most common form of vegetation, although some species of trees and flowers can be found in the region as well. Lessons could explore the tactics these plants use to retain water, such as expansive root systems to collect water over a large area, or spiny leaves that shed less moisture. More advanced lessons could analyze the microscopic plant organisms found on the ground that prevent erosion and support other plant life through symbiotic relationships.
Lessons on animal wildlife can be the most interesting for students. Much like lessons on vegetation, wildlife lessons could look at the variety of survival techniques desert animals employ to limit water use. Lizards, for example, will often find shade during the day to limit water use and then feed at night. Lessons can even focus on desert biodiversity. While some deserts have rats, jack rabbits, and coyotes, other deserts have penguins or polar bears. Studying how each of these animals meets its water needs can be an effective lesson on adaptability and convergent evolution.
Where deserts exist around the world can be an important and illuminating lesson into how they're created and their effect on the nations of the world. Deserts most often occur between latitudes of 15 to 40 degrees on either side of the equator, forming two desert rings around the Earth's surface. Students can be taught about which countries in the world have deserts, as well as their geographical impact on those nations' agriculture, travel and culture.