You may think of the desert as a barren, forlorn place, but the desert is second only to tropical rain forests in the variety of life that lives there. Plants and animals of the desert have adapted to not only survive the harsh climate, but to thrive. Physical and behavioral aspects of desert plants allow them to survive with little water, high temperatures and harsh conditions.
The most striking features of the desert environment are temperature extremes that range from very hot in the middle of the day to extremely cold at night. Though rainfall is infrequent, storms can be short and violent. Soil is predominantly high in mineral deposits and low in organic matter. Repeated water accumulation may cause distinctive layers of salt to form. Plants of the desert have adapted to meet their needs in these types of conditions.
The primary adaptations of desert plants are economical water management systems and maximizing energy gained through photosynthesis. Many plants have small leaves or no leaves at all and grow close to the ground. Leafy plants have a waxy coating or hair-like protrusions that minimize evaporation. Plants require oxygen and water to create photosynthesis. Desert plants often collect oxygen at night through open pores called stomata that close during the day to avoid losing water through evaporation.
Some plants, such as succulents, have special tissues called vacuoles that store water. These plants can survive drought conditions with little or no damage. Cacti and stonecrop are examples of succulents. Other plants adapt extensive root systems that reach deep water sources. One example of this, the tall sage brush, may have plant roots that extend over 82 feet underground. These plants can reach water sources even in the most severe droughts so they are able to photosynthesize throughout the drought season.
Other plants survive climate extremes by going dormant during these extremes. These plants may go dormant during drought periods or during poor growing conditions in the winter. These plants may appear to die, but part of them stays alive below the surface. Other plants--such as many annuals--bloom and produce seeds during an optimal climate condition. Their seeds may remain dormant for years until the next optimal climate condition.
Plants that thrive in saline-rich soil do well in the desert. These plants--called halophytes--maintain organic solutes in their cytoplasm. However, they are not able to conduct photosynthesis as well as other plants.