From the harmless microscopic mites that live on your skin to deep-sea hydrothermal vents, ecosystems are everywhere! An ​ecosystem​ is any defined geographic area where living organisms and abiotic factors interact. Wondering what abiotic factors are? They help organisms survive in some of the grandest and most vital ecosystems on Earth.

Two common ecology terms are ​abiotic​ and ​biotic​. ​Biotic factors​ are the living organisms in an ecosystem such as animals, plants, fungi and bacteria. ​Abiotic factors​ are the nonliving components within an ecosystem such as soil, air, water, temperature, light, chemicals and nutrients.

​Ecologists​ (scientists who study ecosystems) use the term ​ecological niche​ to describe how an organism has evolved to fit into its ecosystem. For example, if an organism interacts with many other organisms in its ecosystem, it would have a broad niche. However, other organisms have evolved very specialized niches. For example, koalas (​Phascolarctos cinereus​) in Australia feed exclusively on the leaves of eucalyptus trees.

The names of the ecosystems broadly describe the environment of that area. Regardless of where they are on the planet, living organisms have often evolved similar traits to live in their environment. For example, alpine ecosystems describe areas high on mountains where the climates and slopes are unsuitable for trees. Here the plants are small, shrubby and have a high tolerance for temperature extremes. Alpine ecosystems can be found anywhere large mountains are located, from New Zealand to Nepal.

Hydrothermal vents are found in the dark depths of the ocean. These underwater volcanos spew hot water of temperatures up to 700 degrees Fahrenheit, along with chemicals and gases such as ammonia, methane and sulfide. Though this may be surprising considering how toxic these vents can be, they are home to over 590 species, including giant tube worms (​Riftia pachyptila​), clams (​Calyptogena magnifica​) and shrimp (​Alvinocarididae​ spp.).

Coral reefs are the calcium carbonate skeletons of the stony coral polyp. Stony coral is a member of the marine invertebrate class Anthozoa, which also includes soft corals and sea anemones. Soft coral polyps don't form a hard exterior.

There are two types of coral reefs: one is found in warm, shallow water less than 230 feet deep with symbiotic, photosynthetic algae, and the other lives in ocean depths between 164 and 9,842 feet deep without photosynthetic algae. Although coral reefs cover less than 1% of the Earth's surface, they are home to approximately 25% of marine organisms.

Kelp is a large brown algae of the order Laminariales in the kingdom Protista​.​ This plant-like organism anchors itself to the ocean floor and grows towards the light. The largest kelp reaches 150 feet long and can grow up to 18 inches per day. Kelp forests are found in shallow waters throughout temperate seas in the Northern and Southern Hemispheres. The dense cover of kelp forests makes them popular nursery grounds for many species.

One of the primary differences between freshwater and marine organisms is the way they deal with ​salinity​ (saltiness). Freshwater organisms have evolved physiology that prevents salts from leaving their body while marine organisms flush out excess salt quickly.

A key difference between lake and river organisms is the presence or lack of water currents, and aquatic organisms' adaptations to these conditions. For example, many fish have evolved streamlined bodies to propel through the water with minimal resistance in rivers.

Temperate forest temperatures range between -22 and 86 degrees Fahrenheit with average annual rainfall between 30 and 59 inches per year. Temperate deciduous forests across North America, Europe, China and Japan visually change throughout the seasons. Think of lush green trees in summer, golden leaves in autumn, bare branches in winter and delicate blossoms in spring. The primary temperate forests of New Zealand, Southern Australia and South America are evergreens, which means they don't lose their leaves seasonally like deciduous trees.

Tropical rainforests spanning the equator cover approximately 3% of the Earth's surface. Their temperature is relatively stable all year, with an average of 68 to 77 degrees Fahrenheit. These forests also experience high humidity and 79 to 394 inches of rain per year.

Tropical rainforest ecosystems have a rich biodiversity, with half the terrestrial plants and animals of the world living in them. Tropical rainforests provide vital ecosystem services, supplying humans around the globe with countless resources including food, fresh water, atmospheric regulation and medicine. According to the Rainforest Alliance, over 60% of anti-cancer drugs originated from rainforest plants alongside medicines for malaria, diabetes, heart disease and tuberculosis, to name a few.

Deserts have minimal rainfall, only about ten inches throughout the year. Temperature extremes can reach over 100 degrees Fahrenheit during the day in summer and then plummet to 25 degrees Fahrenheit at night in winter (and sometimes colder). To survive, desert animals have become efficient at obtaining water from the food they eat and often avoid being active when temperature extremes are at their peak. Desert plants like the mighty saguaro cactus have evolved to store water when it is scarce. Desert plants typically have thick, waxy cuticle-covered leaves, which help prevent evaporation.

The Arctic tundra is located within the Arctic Circle and is identifiable by a lack of trees. A low rainfall of six to ten inches per year (including snowmelt) limits water availability. Many plants survive in this cold desert by remaining dormant under the snow much of the year; they then quickly grow and blossom in spring when water becomes available and temperatures rise from as low as -40 to 64 degrees Fahrenheit.