AP Environmental Science: Unit 1.0-1.3 Ecosystems and Biomes

Biome

An area that shares a combination of average yearly temperature and precipitation (climate).

Tundra

Cold and treeless with low-growing vegetation and permafrost. Not a lot of nutrient availability as frozen soils don't allow nutrients in dead organic matter to be broken down by decomposers. Found just below the arctic circle.

Permafrost

An impermeable, permanently frozen layer that prevents water from draining and roots from penetrating.

Boreal Forests (Taiga)

Forests made up of primarily coniferous evergreen trees that can tolerate cold winters and short growing seasons. Nutrient-poor soil as there are low temperatures and low decomposition rate of dead organic matter. Found below the tundra.

Temperate Rainforests

A coastal biome with moderate temperatures and high precipitation. Found in the Pacific Northwest - despite cold temperatures, does not typically freeze due to the moderating effect of the Ocean.

Temperate Seasonal Forests

Forests with much warmer summers and colder winters than temperate rainforests and are dominated by broadleaf dedicious trees. Nutrient-rich soil with lots of dead organic matter - leaves and warm temperature/moisture for decomposition.

Woodland/Shrubland

Characterized by hot, dry summers and mild, rainy winters. Found in Southern California. Susceptible to fires due to the extended dry summer. Generally warm year round.

Temperate Grassland/Cold Desert

Cold, harsh winters and hot, dry summers. Lowest average rainfall of any temperate biome; fires are common. Rainfalls determine the height of grasses: shortgrass and tallgrass prairies. Fertile soils good for agriculture.

Tropical Rainforests

Warm and wet, with little seasonal temperature variation. Nutrient-poor soil as there is high competition from so many different plant species. Due to the high amounts of rain, many of the nutrients get leached away. Many potential medicines are found from plant and animal compounds.

Tropical Seasonal Forests

Marked by warm temperatures and distinct wet and dry seasons.

Savannas

Relatively open landscapes with grasses and scattered dedicious trees.

Subtropical Desert/Hot Desert

Hot temperatures, extremely dry conditions, and sparse vegetation prevail. Often occur in the rainshadows of mountains.

Aquatic Biomes

Categorized by physical characteristics such as salinity, depth, and water flow. Freshwater and marine.

Streams

Typically narrow and carry relatively small amounts of water. Get their nutrients from shore resources being swept into the water.

Rivers

Typically wider and carry larger amounts of water than streams. Get their nutrients from shore resources being swept into the water.

Rapids

Stretches of turbulent water where water and air mix together.

Lakes and Ponds

Contain standing water, at least some of which is too deep to support emergent vegetation.

Littoral Zone

In a lake, the shallow area of soil and water near the shore where algae and emergent plants such as cattails grow.

Limnetic Zone

In a lake, open water where rooted plants can no longer survive. Dominated by floating algae called phytoplankton.

Profundal Zone

In a lake, a region of water below the Limnetic Zone that sunlight does not reach.

Benthic Zone

The muddy bottom of a lake or ocean.

Oligotrophic Lake

A lake with few nutrients.

Mesotrophic Lake

A lake with some nutrients

Eutrophic Lake

A lake with a lot of nutrients.

Wetlands

An area that is submerged or saturated by water for at least part of the year, but shallow enough to support emergent vegetation. Stores water after heavy rain so it doesn't go rushing into neighborhoods/developments. Filters pollutants and sediments, cleaning/filtering the water. Recharges groundwater (wells, irrigation, drinking water).

Swamps

Wetlands which contain emergent trees.

Marshes

Wetlands with primarily non-woody vegetation.

Bogs

Very acidic wetlands with sphagnum moss and spruce trees.

Salt Marshes

Has non-woody emergent vegetation and is found along the coast in temperate climates, often in estuaries.

Estuaries

Areas along the coast where river water and ocean water mix.

Mangrove Swamps

Occur along tropical and subtropical coasts. Contain salt-tolerant trees whose roots are submerged in water. Anchor the coast during floods/storms and absorb the storm's energy, protecting human development. The leaves excrete the salt that is absorbed by the roots to minimize salt intake.

Intertidal Zone

The narrow band of coastline between high tide and low tide which range from steep, rocky areas to broad, sloping mudflats.

Coral Reefs

Earth's most diverse marine biomes which are found in warm, shallow, tropical waters beyond the coastline.

Coral Bleaching

A phenomenon in which the algae inside corals die, causing the corals to die as well. Scientists believe this is due to a combination of disease and environmental change.

The Open Ocean

A biome away from the shoreline in deeper water in which sunlight can no longer reach the ocean bottom. Produces the most amount of biomass of any biome. Phytoplankton produce a lot of oxygen.

Photic Zone

In an ocean, the upper layer of water that receives enough sunlight to allow photosynthesis.

Aphotic Zone

In the ocean, the deeper layer of water that lacks sufficient sunlight for photosynthesis.

Chemosynthesis

When an organism (bacteria) uses the energy contained in the bonds of methane and hydrogen sulfide to generate energy.

Fundamental Niche

The range of abiotic conditions that a species can tolerate.

Community Ecology

The study of species interaction.

Competition

The struggle of individuals to obtain a limiting resource.

Competitive Exclusion Principle

Two species competing for the same limiting resource cannot coexist.

Resource Partitioning

Two species divide a resource based on differences in the species' behavior or morphology.

Temporal Resource Partitioning

When two species reduce competition by using the same resource at different times.

Spatial Resource Partitioning

When two species reduce competition by using different habitats.

Morphological Resource Partitioning

When two species reduce competition through the evolution in body size or shape.

Predation

The use of one species as a resource by another species.

True Predators

Typically kill their prey and consume most of what they kill.

Herbivores

Consume plants as prey. Typically eat only part of a plant without killing it.

Parasites

Love on or in the organism they consume ("host"). Only consume a small part of their host, rarely causing death. Pathogens are parasites that cause diseases.

Parasitoids

Organisms that lay eggs inside other organisms. When the eggs hatch, the larvae slowly consume the host from the inside out, leading to its death.

Mutualism

Benefits two interacting species by increasing both species' chances of survival.

Commensalism

When one species benefits but the other is neither harmed nor helped.

Symbiotic Relationship

The relationship of two species that live in close association with each other. Commensalism, mutualism, and parasitism.

Individual

One organism.

Population

Group of individuals of the same species.

Community

All living organisms in an area.

Ecosystem

All living and nonliving things in an area.