Unit 1: The Living World - Ecosystems Flashcards
Ecosystem
The interactions between living and nonliving components
Characteristics of ecosystems
○ Some have well-defined boundaries, while others do not
* The biotic and abiotic components of an ecosystem provide the boundaries that distinguish one ecosystem from another
* Some ecosystems are very small
* Each ecosystems interact with each other through the exchange of energy and matter
Biosphere
The region on our planet where life resides
Predator
Eats other organisms
Prey
Organisms eaten by other organisms
Symbiosis
Living together; a close, long-term interaction between two species in an ecosystem
Mutualism
Both organisms benefit
Commensalism
One organism benefits, one organism neither benefits nor is harmed
Parasitism
One organism benefits and one is harmed
Competition
Organisms compete when they seek the same limited resource
Interspecific competition
Members of a different species compete for the same resource
Intaspecific competition
Members of the same species compete for resources (ex: competing for mates)
Producers/autotrophs
Organisms that use the Sun to produce usable energy
Photosynthesis
The use of solar energy to convert carbon dioxide and water into glucose (form of potential energy) and oxygen
Cellular respiration
A process by which cells unlock the energy of chemical compounds
Aerobic respiration
The opposite of photosynthesis, where oxygen and glucose are converted into energy, carbon dioxide, and water
Anaerobic respiration
Cells convert glucose into energy in the absence of oxygen; does not provide as much energy
Consumers/heterotrophs
Organisms incapable of photosynthesis who must obtain their energy by consuming other organisms
Herbivores/primary consumers
Consumers that eat producers
Carnivores
Consumers that eat other consumers
Secondary consumers
Carnivores that eat primary consumers
Tertiary consumers
Carnivores that eat secondary consumers
Trophic levels
The success of organisms consuming one another
Food chain
The sequence of consumption from producers through tertiary consumers
Food web
- A complex model of how energy and matter move through trophic levels
- All species in an ecosystem are connected to one another
Omnivores
Organisms that operate at several trophic levels
Scavengers
Organisms that consume dead animals
Detritivores
Organisms that break down dead tissues and waste products into smaller particles
Decomposers
The fungi and bacteria that complete the breakdown process by converting organic matter into small elements and molecules that can be recycled back into the ecosystem
Gross primary productivity (GPP)
- A measure of the total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
- Indicates the total amount of energy captured by producers
Net primary productivity (NPP)
- The energy captured minus the energy respired by producers
- The greater productivity of an ecosystem, the more primary consumers can be supported
Biomass
The total mass of all living matter in a specific area
Standing crop
The amount of biomass present in an ecosystem at a particular time (not the same as productivity)
Ecological efficiency
- The proportion of consumed energy that can be passed from one trophic level to another
- 10% average across all ecosystems
Trophic pyramid
A method of representing the distribution of biomass among trophic levels
Biogeochemical cycles
The movements of matter within and between ecosystems
Hydrologic cycle
The movement of water through the biosphere
Transpiration
The release of water from leaves during photosynthesis
Evapotranspiration
The combined amount of evaporation and transpiration
Runoff
Water that moves across the land surface and into streams and rivers
Carbon cycle
The movement of carbon around the biosphere
Photosynthesis and the Carbon Cycle
- When producers photosynthesize, they take in CO2 and incorporate some of the carbon into their tissues
○ Some of the carbon is returned as CO2 when organisms respire or die- When organisms die, carbon that was part of the live biomass pool becomes part of the dead biomass pool
Exchange, Sedimentation, and Burial
- Another portion of the CO2 dissolved into the ocean combines with calcium ions in the water to form calcium carbonate (CaCO3)
- A small fraction of the organic carbon in the dead biomass pool is buried and incorporated into ocean sediments before it can decompose into its constituent elements
○ This organic matter becomes fossilized and can become fossil fuels
- A small fraction of the organic carbon in the dead biomass pool is buried and incorporated into ocean sediments before it can decompose into its constituent elements
Extraction and Combustion
- The extraction of fossil fuels by humans is new, beginning when human society started to rely on coal, oil, and natural gas as energy sources
○ Does not alter the carbon cycle- Combustion of fossil fuels by humans and the natural combustion of carbon release carbon into the atmosphere as CO2 or into the soil as ash
Human Impacts on the Carbon Cycle
- In the absence of human disturbance, the exchange of carbon between Earth’s surface and atmosphere is in a steady state
- Since the Industrial Revolution, human activities have had a major influence on carbon cycling
○ Ex: Global warming
Tree harvesting can also affect the carbon cycle
- Since the Industrial Revolution, human activities have had a major influence on carbon cycling
Macronutrients
One of six key elements that organisms need in relatively large amounts; nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur
Limiting nutrient
A nutrient required for the growth of an organism but available in a lower quantity than other nutrients
Nitrogen cycle
The movement of nitrogen around the biosphere
Nitrogen fixation
- The process that converts nitrogen gas in the atmosphere (N2) into forms of nitrogen that producers can use
- Biotic and abiotic
Nitrification
The conversion of ammonium (NH4+) into nitrite (NO2-) and then intro nitrate (NO3-)
Assimilation
The process by which organisms incorporate elements into their tissues
Mineralization
The process by which fungal and bacterial decomposers break down the organic matter found in dead bodies and waste products and convert it into inorganic compounds
Ammonification
The process by which fungal and bacterial decomposers break down the organic nitrogen found in dead bodies and waste products and convert them into inorganic ammonium
Denitification
The conversion of nitrate and a series of steps into the gases nitrous oxide, and eventually, nitrogen gas, which is emitted into the atmosphere
Leaching
The transportation of dissolved molecules through the soil via groundwater
Phosphorus cycle
The movement of phosphorus around the biosphere
Assimilation and Mineralization in the Phosphorus Cycle
Producers on land and in the water take up inorganic phosphate and assimilate the phosphorus into their tissues as organic phosphorus
Algal bloom
A rapid increase in the algal population of a waterway
Hypoxic
Low in oxygen
Dead zone
When oxygen concentrations become so low that it kills fish and other aquatic animals
Terrestrial biomes
Geographical regions that each have a particular combination of average annual temperature and precipitation and contain distinctive plant growth forms that are adapted to that climate
Aquatic biomes
Biomes categorized by particular combinations of salinity, depth, and water flow
Habitat
An area where a particular species lives in nature
Tundra
- A cold and treeless biome with low-growing vegetation
- Found in northernmost regions of the Northern Hemisphere and Antarctica
- Permafrost: An impermeable, permanently frozen layer of soil that prevents deep-rooted trees from growing
Boreal forest
- A forest biome made up primarily of coniferous evergreen trees that can tolerate cold winters and short growing seasons
- Found between 50 N and 60 N in Europe, Russia, and North America
- Covered in a thick layer of organic material, but are poor in nutrients
- Animal species include beavers, brown bears, and wolverines
Temperate rainforest
- A coastal biome typified by moderate temperatures and high precipitation
- Found along the west coast of North America from northern California to Alaska, in southern Chile, in Australia, Tasmania, and New Zealand
- Animal species include black-tailed deer, Pacific giant salamander, and the Pacific treefrog
Temperate seasonal forest
- A biome with warm summers and cold winters with over 1 m (39 inch) of precipitation annually
- Found in eastern USA, Japan, China, Europe, Chile, and eastern Australia
- Animal species include white-tailed deer, red foxes, and gray squirrels
Woodland/shrubland
- A biome characterized by hot, dry summers and mild, rainy winters
- Found on the coast of southern California, in southern America, in southwestern Australia, in southern Africa, and in a large region surrounding the Mediterranean Sea
- Favors the natural occurrence of wildfires
- Plants are adapted to fires and droughts
- Animals include the California quail, black-tailed jackrabbit, and the San Joaquin kit fox
Temperate grassland
- A biome characterized by cold, harsh winters, and hot, dry summers
- Found in the Great Plains, in South America, and in central Asia and eastern Europe
- Fires are common
- Typical plants include grasses and nonwoody flowering plants
Tropical rainforest
- A warm and wet biome found between 20 N and 20 S of the equator, with little seasonal temperature variation and high precipitation
- Tropical rainforests contain more biodiversity per hectare than any other terrestrial biome
- Animal species include jaguars, orangutans, and red-eye treefrogs
Tropical seasonal forest/savanna
- A biome marked by warm temperatures and distinct wet and dry seasons
- Found in Central America, on the Atlantic coast of South America, in southern Asia, in northwestern Australia, and in sub-Saharan Africa
- Savannas: Relatively open landscapes dominated by grasses and scattered deciduous trees
Subtropical desert
- A biome prevailing at approximately 30 N and 30 S, with hot temperatures, extremely dry conditions, and sparse vegetation
- Includes the Mojave Desert in southwestern USA, the Sahara in Africa, the Arabian Desert of the Middle East, and the Great Victoria Desert of Australia
- Cacti, euphorbs, and succulent plants are well-adapted to this region
- Annual plants grow rapidly during periods of rain
Streams and rivers
- Characterized by flowing fresh water that may originate from underground springs or as a runoff from rain or melting snow
- Streams are more narrow, while rivers are wider
- Most streams and rivers have few plants or algae to act as producers
- Rapids: Stretches of turbulent waters where water and air are mixed together
○ Allows atmospheric oxygen to dissolve into the water for animal species
Lakes and ponds
- Contain standing water
- Littoral zone: The shallow area of soil and water near the shore where algae and emergent plants grow
- Limnetic zone: A zone of open water in lakes or ponds
- Profundal zone: A region of water where sunlight does not reach, below the limnetic zone in very deep lakes
- Benthic zone: The muddy bottom of a lake, pond, or ocean
Oligotrophic
A lake with a low level of productivity
Mesotrophic
A lake with a moderate level of productivity
Eutrophic
A lake with a high level of productivity
Freshwater wetlands
- An aquatic biome that is submerged or saturated by water for at least part of each year, but shallow enough to support emergent vegetation
- Includes swamps, marshes, and bogs
- One of the most productive biomes on the planet
○ Many bird species depend on wetlands during migration or breeding
Salt marshes
- Coastal wetlands that are flooded and drained by salt water brought in by the tides
- They are marshy because the soil may be composed of deep mud and peat
- occur worldwide, particularly in middle to high latitudes
Mangrove swamps
- Coastal wetlands found in tropical and subtropical regions
- Characterized by halophytic (salt loving) trees, shrubs and other plants growing in brackish to saline tidal waters
- often found in estuaries
Intertidal zones
- The area where the ocean meets the land between high and low tides
- Sea creatures arrange themselves vertically in the intertidal zone depending on their abilities to compete for space, avoid predators from above and below, and resist drying out
Coral reefs
- Made of the calcium carbonate skeletons of corals – small immobile animals closely related to jellyfish
- Some of the most diverse ecosystems on Earth
Open ocean
- the area of the ocean outside of coastal areas
- the largest of all the biomes and consists of many different ecosystems
- Seaweed is the main plant found
- Species here are affected by wave and wind activity, pressure, water temperature and prey
