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.
Generalists
Able to survive on a wide variety of food resources
Generalists
Able to withstand a wide range of environmental conditions
Generalists
Live in broad niches
Specialists
Specific/limited number of prey
Specialists
Prone to extinction, sensitive to environmental change
Specialists
Live in narrow niches
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.
Commensalism
The interaction between two species whereby one organism benefits and the other species is not affected.
Competition
It can be either intraspecific and interspecific. It 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.
predator–prey relationships
Competition is prominent in ________, with the predator seeking food and the prey seeking survival.
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.
Opportunistic predators
These predators kill and eat almost anything.
Specialist predators
These predators 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.
Predator-prey cycles
These are based on a feeding relationship between two species:
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
average air temperature
amount of rainfall
The geographical distribution of the various terrestrial biomes is controlled primarily by the ______ and the _______ the biome receives.
Deserts
Defined in terms of the amount of rainfall they receive, not temperature.
Deserts
They cover about 20% of Earth’s surface and occur where rainfall is less than 20 inches (50 cm) per year.
Arctic tundra
It 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
They have sharp spines that create shade, reduce drying airflow, discourage herbivores and reflect sunlight.
They also secrete toxins into the soil to prevent interspecific completion.
Wildflowers
They are dependent on water for germination;
They have short life spans;
They perform their entire life cycle from seed to flower to seed within a single growing season
Desert animals
They are generally small.
They are often nocturnal.
They have small surface areas.
They spend time in underground burrows where it is cold.
Aestivation
A summer hibernation.
Forests
It cover about one-third of Earth's land surface, mostly in North America, the Russian Federation, and South America, and account for 75% of gross primary productivity and plant biomass.
Ecozones
_____ like boreal forests near the poles and tropical forests near the equator are formed by forests at different latitudes and elevations.
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
Animals include numerous birds, bats, small mammals, and insects.
Decomposition is rapid and soils are subject to heavy leaching.
Distinct seasonality where winter is absent and only two seasons are present.
Tropical Rainforests
The length of daylight is 12 hours and varies a little year-round
Large diversity of species.
Occur near the equator.
Annual rainfall exceeds 80 inches (200 cm) and is evenly distributed.
Plants are highly diverse.
Tropical Rainforests
Tree canopy is multilayered and continuous, allowing little light penetration.
Trees have buttressed trunks, shallow roots, and large, dark green leaves.
Overstory
The uppermost trees in a forest.
Understory
Layer made up of young trees, short species of trees, shrubs, and soft-stemmed plants.
Temperate Deciduous Forests
Occur in eastern North America, northeastern Asia, and western and central Europe.
Have a distinct winter, moderate climate, and a 140–200-day growing season during four to six frost-free months.
Temperate Deciduous Forests
Temperature varies from –20°F to 85°F (–30°C to 30°C).
Precipitation averages 30–60 inches (75–150 cm) per year.
Fertile soil is enriched by decaying leaf litter.
Temperate Deciduous Forests
The tree canopy allows light to penetrate, resulting in well-developed and diverse understory vegetation and animal stratification.
Temperate Coniferous Forest
Found in temperate regions with warm summers, cool winters, and enough rainfall to support forests.
Common in coastal areas with mild winters and heavy rainfall, or inland in drier climates or mountains.
Temperate Coniferous Forest
These forests have cedar, cypress, fir, juniper, pine, redwood, and spruce.
These forests have two layers:
Overstory
Understory
Some forests have a shrub layer.
Temperate Coniferous Forest
In winter, when food is scarce, many animals hibernate to conserve energy and build fat in summer.
Birds have feathers and many animals have thick fur to protect them from cold weather.
Some animals migrate to warmer climates during the winter months.
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, such as pines, spruces, and larches.
Northern Taiga
It is more barren as it approaches the tree line and the tundra biome.
Grasslands
These are characterized as lands dominated by grasses rather than by large shrubs or trees.
Savannas
These are grasslands with scattered individual trees and cover almost half the surface of Africa and large areas of Australia, South America, and India.
Temperate Grasslands
Here grasses are the dominant vegetation, while trees and large shrubs are absent.
Tundra
It has 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
Due to the ________’s unique conditions, the biota is highly specialized and sensitive to environmental change.
Arctic tundra
It circles the North Pole and extends south to the taiga, is cold, dry, and desert-like.
Permafrost
A layer of permanently frozen subsoil.
Alpine tundra
It is located on mountains throughout the world at high altitudes where trees cannot grow.
Aquatic Biomes
Antarctic, marine, lakes, wetlands, and rivers
Antarctica
It has the coldest climate on Earth.
ice sheet
It is formed from compressed snow that rarely melts.
Krill
These are key food sources in this ecosystem and serve as food for many predators.
75%
Oceans cover approximately ____ of Earth’s surface and have a salt concentration of about 3%.
Evaporation
______ of seawater is the primary source of most of the world’s rainfall.
Convection
The circular motion that occurs when warmer air or liquid rises, while the cooler air or liquid sinks.
conveyor belt
Thermohaline currents drive a "_____" of ocean water that moves constantly, unlike most surface currents, which are driven by winds.
Littoral Zone
Also known as the intertidal zone, it is the part of the ocean that is closest to the shore.
Neretic Zone
Also known as the sublittoral zone, this zone extends to the edge of the continental shelf.
Photic Zone
The uppermost layer of water in a lake or ocean that is exposed to sunlight down to the depth where 1% of surface sunlight is available.
Photic Zone
The layer just above the depth where the rate of carbon dioxide uptake by plants is equal to the rate of carbon dioxide production by animals.
Corals
These are marine invertebrates that typically live in compact colonies of many identical individual polyps.
Polyps
Small, sac-like animals with a set of tentacles surrounding a central mouth opening and an exoskeleton made of calcium carbonate at the base.
zooxanthellae
Most corals obtain the majority of their energy and nutrients from photosynthetic unicellular dinoflagellates, commonly known as _______, that live within their tissues.
Fringing reefs
They grow near the coastline around islands and continents and are separated from the shore by narrow, shallow lagoons.
They are the most common type of reef.
Barrier reefs
These are also parallel to the coastline but are separated by deeper, wider lagoons.
At their shallowest point, they can reach the water’s surface, forming a “barrier” to navigation.
Atolls
These are rings of coral that create protected lagoons and are usually located in the middle of the sea.
They usually form when islands, often the tops of underwater volcanoes, surrounded by fringing reefs, sink into the sea, or the sea level rises around them.
Lakes
These are large natural bodies of standing freshwater formed when precipitation, runoff, or groundwater seepage fills depressions in Earth’s surface.
Artificial lakes
These are constructed for hydroelectric power generation, recreational purposes, industrial and agricultural use, and/or domestic water supply.
Benthic Zone
The bottom of lake, organisms can tolerate cool temperatures and low oxygen levels.
Limnetic Zone
A well-lit, open surface water, farther from shore, extends to a depth penetrated by light, occupied by phytoplankton, zooplankton, and higher animals; produces food and oxygen that supports most of a lake’s consumers
Littoral Zone
It is shallow, close to shore, extends to depth penetrated by light; rooted and floating plants flourish
Profundal Zone
It is deep, no-light regions, too dark for photosynthesis; low oxygen levels; inhabited by fish adapted to cool, dark waters
Oligotrophic (Young Lake)
Deep, cold, small surface area relative to depth; nutrient-poor, phytoplankton are sparse; not very productive; doesn’t contain much life; waters often very clear; and sediments are low in decomposable organic matter.
Mesotrophic (Middle-Aged Lake)
Moderate nutrient content and moderate amounts of phytoplankton; reasonably productive.
Eutrophic (Old Lake)
Shallow, warm, large surface area relative to depth; Waters often murky;
stratification
The ______ or layering of water in lakes is the result of density changes caused by shifts in temperature.
hypolimnion
Deep water is insulated from the sun and stays cool and denser, forming a lower layer called the _______.
Seasonal turnover
_______ refers to the exchange of surface and bottom water in a lake or pond that happens twice a year.
Fall Turnover
With the arrival of fall and cooler air temperatures, water at the surface of a lake begins to cool and becomes heavier.
During this time, strong fall winds move the surface water around, which promotes mixing with deeper water.