APES FULL EXAM REVIEW

Ecosystem

A community of living (biotic) organisms interacting with the non-living (abiotic) components of their environment as a system through various nutrients and energy cycles.

Organism

A living thing that can function on its own.

Species

Organisms that resemble each other; are similar in genetic makeup, chemistry, and behavior; and are able to interbreed and produce fertile offspring.

Interspecific

Means between different species.

Population

Organisms of the same species that interact with each other and occupy a specific area.

Community

Population of different species.

Ecological Niche

A particular area within a habitat occupied by an organism, as well as the function of that organism within its ecological community.

Physical environment

It influences how organisms affect and is affected by resources and competitors.

Niche

It reflects the specific adaptations that a species has acquired through evolution.

Symbiosis

A term used to describe any type of close and long-term biological interaction between two different biological organisms of the same or different species.

Amensalism

The interaction between two species whereby one species suffers and the other species is not affected.

Example of Amensalism

The black walnut tree releases a chemical that kills neighboring plants.

Commensalism

The interaction between two species whereby one organism benefits and the other species is not affected.

Forms of Commensalism

Using another organism for transportation, using another organism for housing, and using something that another organism created.

Competition

It can be either intraspecific and interspecific and is the driving force of evolution whether it is for food, mating partners, or territory.

Intraspecific

Competition between members of the same species.

Interspecific

Competition between members of different species.

Mutualism

The interaction between two species whereby both species benefit.

Parasitism

The interaction between two species whereby one species is benefited, and the other species is harmed.

Predation

Predators hunt and kill their prey.

Opportunistic predators

Predators that kill and eat almost anything.

Specialist predators

Predators that only prey upon certain organisms.

Saprottrophism

Saprotrophs obtain their nutrients from dead or decaying plants or animals through the absorption of soluble organic compounds.

Law of Tolerance

It states that the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors.

Limiting Factor

Any abiotic factor that limits or prevents the growth of a population.

Limiting factors in terrestrial ecosystems

May include the level of soil nutrients, the available amount of water and light, and the temperature.

Limiting factors in aquatic ecosystems

May include the pH of the water, the amount of dissolved oxygen, light, or the degree of salinity.

Predator-prey cycles

Based on a feeding relationship between two species where if the prey species rapidly multiply, the number of predators increases until the predators eventually eat so many of the prey that the prey population dwindles again.

Morphological partitioning

It occurs when two species share the same resource but have evolved slightly different structures to utilize the same resource.

Spatial partitioning

It occurs when competing species use the same resource by occupying different areas or habitats within the range of occurrence of the resource.

Temporal partitioning

It occurs when two species eliminate direct competition by utilizing the same resource at different times.

Biomes

These are major regional or global biotic communities characterized by dominant forms of plant life and the prevailing climates.

Determinants of biomes

Temperature and precipitation are the most important determinants of biomes.

Geographical distribution of biomes

The geographical distribution of the various terrestrial biomes is controlled primarily by the average air temperature and the amount of rainfall the biome receives.

Deserts

Defined in terms of the amount of rainfall they receive, not temperature.

Desert coverage

Deserts cover about 20% of Earth's surface and occur where rainfall is less than 20 inches (50 cm) per year.

Daily temperature extremes in deserts

Daily extremes in temperature result from exceptionally low humidity as water vapor tends to block solar radiation.

Desert location

Most deserts are located between 15° and 35° north and south latitudes.

Arctic tundra

Arctic tundra is a cold desert due to the low amount of rainfall it receives yearly.

Succulents

Plants that have fleshy leaves or stems that store water.

Cactus adaptations

They have sharp spines that create shade, reduce drying airflow, discourage herbivores, and reflect sunlight.

Cactus toxins

They also secrete toxins into the soil to prevent interspecific competition.

Wildflowers

They are dependent on water for germination and perform their entire life cycle from seed to flower to seed within a single growing season.

Desert animals

They are generally small, often nocturnal, and have small surface areas.

Aestivation

A summer hibernation.

Forests coverage

Forests cover about one-third of Earth's land surface, mostly in North America, the Russian Federation, and South America.

Forest productivity

Forests account for 75% of gross primary productivity and plant biomass.

Forest layers

Closed canopy: Tree crowns cover more than 20% of the ground's surface; Open canopy: Tree crowns cover less than 20% of the ground surface.

Tropical rainforests

They occur near the equator and have an annual rainfall exceeding 80 inches (200 cm) that is evenly distributed.

Temperate deciduous forests

They occur in eastern North America, northeastern Asia, and western and central Europe, with a distinct winter and a 140-200-day growing season.

Temperature range in temperate deciduous forests

Temperature varies from -20°F to 85°F (-30°C to 30°C).

Precipitation in temperate deciduous forests

Precipitation averages 30-60 inches (75-150 cm) per year.

Soil in temperate deciduous forests

Fertile soil is enriched by decaying leaf litter.

Tree Canopy

Allows light to penetrate, resulting in well-developed and diverse understory vegetation and animal stratification.

Deciduous Trees

Includes oaks, hickories, beeches, hemlocks, maples, cottonwoods, elms, willows, and spring-flowering herbs.

Temperate Forests

Development, land clearing, and timbering have left few temperate forests.

Temperate Coniferous Forest

Found in temperate regions with warm summers, cool winters, and enough rainfall to support forests.

Overstory

The uppermost trees in a forest.

Understory

Layer made up of young trees, short species of trees, shrubs, and soft-stemmed plants.

Shrub Layer

Some forests have a shrub layer.

Grassy Understories

Often burn in ecologically important wildfires.

Conical Trees

Shed snow and protect branches.

Dark Green Needles

Absorb more light for photosynthesis.

Needles

Have thick waxy coatings, waterproof cuticles, and sunken stomates.

Transpiration

Reduced by needles which decrease surface area.

Hibernation

Many animals hibernate in winter to conserve energy and build fat in summer.

Taiga

Largest terrestrial biome; found in northern Eurasia, North America, Scandinavia, and two-thirds of Siberia.

Southern Taiga

Also known as boreal forest, consists primarily of cold-tolerant evergreen conifers with needle-like leaves.

Northern Taiga

More barren as it approaches the tree line and the tundra biome.

Harsh Climate

Limits both productivity and resilience in the taiga.

Soil in Taiga

Thin, nutrient-poor, and acidic.

Grasslands

Characterized as lands dominated by grasses rather than by large shrubs or trees.

Savannas

Grasslands with scattered individual trees, covering almost half the surface of Africa and large areas of Australia, South America, and India.

Savanna Climate

Found in warm or hot climates with annual rainfall of 20 to 50 inches (50-130 cm) concentrated in six to eight months.

Savanna Soil

Drains quickly and has a thin layer of humus to nourish vegetation.

Temperate Grasslands

Grasses are the dominant vegetation, while trees and large shrubs are absent.

Examples of Temperate Grasslands

Include the veldts of South Africa, the pampas of Argentina, the steppes of Russia, and the plains and prairies of central North America.

Climate in Temperate Grasslands

Characterized by hot summers and cold winters, with moderate rainfall.

Deep Grass Roots

Grow and decay in dark, fertile soil, enriching it.

Seasonal drought

Prevents woody shrubs and trees from establishing.

Cottonwoods, oaks, and willows

Trees that grow in river valleys along with some flowers.

Tundra

Characterized by extremely low temperatures, large repetitive population changes, limited soil nutrients, little precipitation, low biotic diversity, poor drainage, short growing and reproductive seasons, and simple vegetation structure.

Arctic tundra

Circles the North Pole, extends south to the taiga, and is cold, dry, and desert-like.

Growing season in Arctic tundra

Averages around 50 days per year.

Summer temperatures in Arctic tundra

Range from 37°F to 54°F (3°C to 12°C).

Winter temperatures in Arctic tundra

Average -30°F (-34°C).

Yearly precipitation in Arctic tundra

Is 6 to 10 inches (15 to 25 cm).

Permafrost

A layer of permanently frozen subsoil.

Bogs and ponds in Arctic tundra

Form when water saturates the upper surface, providing moisture for cold-resistant plants.

Plant adaptations in Arctic tundra

All plants are adapted to sweeping winds and disturbances of the soil.

Food webs in Arctic tundra

Are simple and characterized by low biodiversity.

Herbivorous mammals in Arctic tundra

Include lemmings, caribou, Arctic hares, and squirrels.

Carnivorous animals in Arctic tundra

Include Arctic foxes, wolves, and polar bears.

Migratory birds in Arctic tundra

Include ravens, falcons, terns, snowbirds, and various species of gull.

Alpine tundra

Located on mountains throughout the world at high altitudes where trees cannot grow.

Growing season in alpine tundra

Is approximately 180 days, with nighttime temperatures usually falling below freezing.

Aquatic biomes

Comprise Antarctic, marine, lakes, wetlands, and rivers and streams.

Nutrient acquisition in aquatic organisms

Aquatic organisms get nutrients from water.

Thermal capacity of water

Is high, so most aquatic organisms don't need to regulate temperature.

Antarctica

Has the coldest climate on Earth.