Deserts

Life that thrives on very little water.

Dry landscapes of sand, rock and scrub where life is adapted to extreme conditions.

Overview

Deserts are defined by how little rain they receive, not by heat — some are hot, others are cold. Plants store water, grow deep roots or wait as seeds for a rare rain. Animals avoid the heat by being active at night, sheltering underground and getting most of their water from food.

Climate

Very low rainfall, dry air and large differences between day and night temperatures.

Where it is found

Every continent — including the Sahara, Arabia, the Mojave and the Atacama.

Vegetation

Cacti, succulents, drought-tolerant shrubs and trees such as the Joshua tree and the dragon blood tree.

Living conditions

Water: Rain is rare and unpredictable; some years have almost none.
Temperature: Days can be very hot and nights cold because dry air loses heat fast.
Soil: Thin, sandy or rocky soils hold little water.

Key facts

Precipitation: Less than about 250 mm a year (Common definition)
Area: About one-third of Earth’s land surface (USGS)
Temperature: Large daily swings; hot and cold deserts

How the ecosystem works

Water saving: Waxy leaves, spines and nighttime breathing reduce water loss.
Night life: Many animals are active only after sunset.
Boom and bust: Rare rains trigger rapid flowering and breeding.

Food web

Producers: Joshua tree, Dragon blood tree, Cacti
Herbivores: Desert rodents, Insects
Predators: Snakes & lizards, Foxes
Decomposers: Beetles, Soil microbes

Biodiversity

Fewer species than wetter habitats, but many are found nowhere else — their adaptations to drought are among the most remarkable in nature.

Threats

Climate change — Hotter, drier conditions push species beyond their limits.
Development — Cities, roads and energy projects fragment fragile landscapes.
Water extraction — Pumping groundwater dries out springs and oases.
Invasive grasses — Non-native grasses fuel fires that desert plants cannot survive.

Conservation

Desert ecosystems recover very slowly — tracks and damage can last for decades. Protecting them preserves unique species and the knowledge of how life survives extreme conditions.

Protecting springs and oases.
Limiting off-road damage.
Controlling invasive grasses and fire.