Desert biomes, arid ecological communities or bionetworks, cover one-fifth of the world's land mass and are extremely dry, with little rainfall.There are four main types of desert: hot and dry; coastal; semiarid; and cold. Coastal deserts feature moderately cool winters followed by long, warm summers. The soil is sandy and dry with a high salt content. The flora and fauna that exists in these areas are not particularly diverse and are extremely hardy. Besides being drought tolerant, the plants also feature special shallow root systems to catch any rainfall, and wide, thick leaves for storing moisture.
Much of a coastal desert landscape is dominated by scrub, which are twiggy plants, sometimes bearing thorns. They have small leaves to prevent moisture loss and are shallow-rooted. Chaparraal is a coastal scrub and has the ability to live on just the moisture in the air from fog. Salt bush, euphorbia, senesio, chrysothamnus and artemesia are some of the other plants in a scrub forest. Rice grass and Black sage also are found among scrub growth.
Cacti and succulents
We think of deserts as being the home of cactus plants, but actually the coastal desert has few. The saguaro, a tall, columned cactus, is a classic feature of this area. It stores moisture in its barrel- shaped body. A cousin of the saguaro is the cardon, the largest cactus in the world. Succulents like lithops are dotted here and there. Generally low-growing with thick fleshy leaves, succulents do need water and may be in shadow or depressions that collect moisture from fog.
There are a few species of tree that survive the nutrient-poor sandy soils of a coastal desert. The mesquite is a classic skeleton of a tree that is used for it's wood. The ironwood tree can get up to 30 feet in height or it can grow as a short, 2-foot-high bush. Tall plants are rare in the coastal desert, which may average only 5 inches of rain per year.
This bush is found commonly in coastal scrub regions and sends out a pungent smell. They are slow growing and the seeds are difficult to germinate. Consequently, it takes a long time to regrow them once they are harvested, usually for herbal remedies. Creosote can live up to 90 years and even a small bush can be 10 years old, due to the slow-growth pattern.