Ecosystems

Arctic tundra commonly has permafrost. Alpine tundra is defined by high-elevation conditions and need not have permanently frozen ground.

Includes savannas and prairies

Also called boreal forest

Food webs connect many chains

Convert energy into organic matter

Captures much sunlight

A productive nursery habitat

Can be hot or cold

The hunter is the predator

Reefs support high biodiversity but are vulnerable to warming, pollution, disease, and physical damage.

They are not seaweed and can form important nursery habitats for fish and other animals.

Kelp can grow quickly and provide food and shelter in cool, nutrient-rich coastal water.

By limiting urchins that graze kelp, sea otters can create a trophic cascade.

It is more realistic than a single food chain because most organisms have multiple relationships.

Primary succession starts without soil

Ticks on mammals are an example

Depends on resources

Often excess nitrogen or phosphorus

Reduces atmospheric carbon dioxide

Can increase population size

Can decrease population size

Performed by certain bacteria

Upwelling can support productive fisheries by feeding phytoplankton near the surface.

It can make it harder for some organisms to build shells or skeletons from calcium carbonate.

Good management considers reproduction, habitat, bycatch, enforcement, and community livelihoods.

Extremely biodiverse

Marshes are grass-dominated

Includes resources and interactions

Removal can reshape a community

Not every introduced species is invasive

Includes genes, species and ecosystems

Supports species from both

The water column

Currents are driven by wind, temperature, salinity, Earth’s rotation, and the shape of ocean basins.

In some coastal caves and cenotes, a halocline can be visibly striking where fresh and salt water meet.

Temperature can change quickly with depth, especially in warm, stratified water.

Their roots trap sediment, reduce wave energy, and create shelter for many species.

Estuaries are productive transition zones and nurseries for many species.

Many marine creatures use bioluminescence for signaling, camouflage, attraction, or defense.

They expose organisms to rapid changes in temperature, salinity, waves, and air.

The Sun also influences tides, especially during new and full moons.

Rules vary widely, from limits on certain activities to fully protected no-take zones.

Bycatch reduction can involve gear changes, timing, escape devices, and better monitoring.

A single large carcass can support scavengers and specialized organisms for years.

Pressure is high, temperatures are low, and many organisms have distinctive adaptations.

Vent ecosystems can be powered by chemical energy rather than sunlight.

Some bacteria at deep-sea vents use chemicals such as hydrogen sulfide as an energy source.

This behavior is called natal homing, though routes and precision vary among species.

Preventing debris at its source is more effective than trying to collect it after it spreads.

Color changes with depth, particles, plankton, sky conditions, and the angle of light.

Average seawater salinity is often described as about 35 parts per thousand, though it varies.

Some blooms are natural and beneficial; others can be harmful depending on species and conditions.