Desert ecosystems are first and foremost defined and limited by scarceness of water. Heat stress and limitations of food and nutrients resources are secondarily correlated. Water inputs are spatiotemporally highly variable and many of the ecosystem functions are pulse driven. Desert regions are found globally in the subtropical high pressure belts, in the rain shadow of mountain ranges or the continental interior, and bordering cold ocean currents. Even though primary productivity by plants and microorganisms is relatively low, species richness and taxonomical diversity can be fairly high. Taxonomically different organisms evolved traits to cope with water stress and often similar life forms arose due to convergent evolution. Typical desert organisms show traits that allow them to avoid periods of extreme aridity in inactive stages and/or to store water for use during drought; a few organisms evolved traits to tolerate the lack of water altogether. Microbial decomposition in deserts is limited due to aridity and the energy flow in desert ecosystems is dominated by detrivores that form the base of the food chain. Humans show adaptations to hot desert climates and a number of cultural practices arose that enable human populations to live near or in deserts.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)
- Environmental Science(all)
- Human ecology
- Primary production
- Resource pulse
- Species interaction