2 Introduction To Ecology Ecology – the study of living things and their relationship with each other and with the environment*Ecology can be studied at different levels, from a local to a global scale
4 Levels of Organization 1. Organism – an individual living thing, such as an alligator2. Population – group of same species that lives in one area, such as a group of alligators living in a swamp
5 Levels of Organization 3. Community – all of the living things in a given area. Ex: alligators, fish, plants, birds.4. Ecosystem –all of the living andnonliving thingsin a given area.Ex: All of the above andsoil, rocks, water, etc.
6 Levels of Organization 5. Biome – a major regional or global community of organisms, usually characterized by the climate conditions and plant communities that thrive there.Examples: tropical, grassland, desert, temperate, taiga, tundra
7 Levels of Organization 6. Biosphere – portion of the Earth where all life exists
9 Ecological research methods include… Observation – the act of carefully watching something over time.Direct: naked eye, binocularsIndirect: feces, recent killExperimentation – scientists can perform experiments in the lab or the field.Modeling – Using computer or mathematical models to describe and model nature
10 13.2 Biotic and Abiotic Factors Every ecosystem includes both living and nonliving factors
11 Biotic factors are living things, or things that were once living Examples: plants, animals, fungi, bacteriaEach organism plays a particular role in the ecosystem.
12 Abiotic Factors are nonliving Examples: moisture, temperature, wind, sunlight, soil.The balance of these factors determines which living things can live in a particular environment.
13 Biodiversity is important to an ecosystem Biodiversity is the assortment, or variety, of living things in an ecosystem.Keystone species: A species that has an unusually large effect on its ecosystem. The loss of a keystone species from an ecosystem can have a ripple effect.Example: Beavers create dams which are an ecosystem used by a wide variety of species.
14 13.3 Energy in EcosystemsLife in an ecosystem requires a source of energyProducers provide energy for other organisms in an ecosystem.Producer: An organism that get their energy from non-living resources. Example: PlantsAlso called autotrophsGet energy from photosynthesis or chemosynthesisChemosynthesis: process by which an organism forms carbohydrates using chemicals as an energy source.
15 Energy In EcosystemsConsumers are organisms that get their energy by eating other living thingsAlso called heterotrophsAll consumers somehow depend on producers for food.Examples: wolf, human, rabbit
16 13.4: Food chains and food webs Food chains and food webs model the flow of energy in an ecosystem.
17 Food Chains & Food Webs Food chain: a model that shows a sequence of feeding relationships.Shows the transfer ofenergy from oneorganism to anotherEach level ofnourishmentin a food chain iscalled a trophic level
18 Not all consumers are alike. Herbivores: Eat only plants. Example: rabbitsCarnivores: Eat only animals. Example: lionOmnivore: Eat both plants and animals. Example: kangaroo rat.Detritivores: Eat detritus, or dead organic matter.Examples: millipedeDecomposer: A type of detritivore that breaks down organic matter into simpler compounds, returning vital nutrients back into their environment.Example: fungi
19 Other types of consumers… Specialists: a consumer that primarily eats one specific organisms or feeds on a very small number of organisms.Very sensitive to changes in the availability of prey.Generalists: consumers that have a varying diet (most species).
20 Energy flows from the lowest trophic level to the highest trophic level Producer to primary consumer to secondary consumer to tertiary consumerPrimary consumers are herbivores (or omnivores)Secondary consumers are carnivores (or omnivores)Tertiary consumers are carnivores (or omnivores)
21 A food web is a model that shows the complex network of feeding relationships and the flow of energy within an ecosystem.
22 Energy PyramidsA pyramid of numbers shows the numbers of individual organisms at each trophic level in an ecosystem.Between each tier of an energy pyramid, up to 90 percent of the energy is lost into the atmosphere as heat.Only 10 percent of the energy at each tier is transferred from one trophic level to the next.A vast number of producers are required to support even a few top level consumers.tertiaryconsumerssecondaryprimaryproducers55000500,0005,000,000
23 3.5 KEY CONCEPT Matter cycles in and out of an ecosystem. It changes form, but does not disappear.The total amount of matter remains the same.sWPxQymA
24 Water cycles through the environment. The hydrologic, or water, cycle is the circular pathway of water on Earth.Organisms all have bodies made mostly of water.precipitationcondensationtranspirationevaporationwater storagein oceansurfacerunofflakegroundwaterseepage
25 Elements essential for life also cycle through ecosystems Elements essential for life also cycle through ecosystems -examples: oxygen, carbonA biogeochemical cycle is the movement of a particular chemical through the biological and geological parts of an ecosystem.
26 The Oxygen CycleOxygen can cycle indirectly through an ecosystem by the cycling of other nutrients.oxygenrespirationcarbondioxidephotosynthesis
27 The Carbon Cycle Carbon is the building block of living organisms. Carbon comes in all three forms (solid, liquid, gas)CO2 gasHCO3 (bicarbonate- dissolved in water)Fossil Fuels (underground) oil, natural gas, coalCarbonate rocks (limestone)Dead Organic Matterfossil fuelsphotosynthesiscarbon dioxidedissolved in waterdecompositionof organismsrespirationcarbondioxidein aircombustion
28 The nitrogen cycle mostly takes place underground. Some bacteria convert gaseous nitrogen into ammonia through a process called nitrogen fixation.Some nitrogen-fixing bacteria live in nodules on the roots of plants; others live freely in the soil.Lightningcan splitnitrogenmolecules in theatmosphere whichcan add nitrogento the soil.nitrogen inatmosphereanimalsdenitrifyingbacterianitrifyingammoniumammonificationdecomposersplantnitrogen-fixingbacteria in soilbacteria in rootsnitratesnitrites
29 Nitrogen Cycle Continued Ammonia (NH3) released into the soil is transformed into ammonium – some is taken up by plantsNitrifying bacteria change the ammonium into nitrate.Nitrate is taken up by plants and converted into organic compounds like amino acids and proteins.Nitrogen moves through the food web and returns to the soil during decomposition as ammonium.
30 Phosphorus CycleThe phosphorus cycle takes place at and below ground level – it does not include an atmospheric portion.1. Phosphate is released by the weathering of rocks.2. Plants and fungi found near plant roots are able to take up phosphate3. Phosphorus moves through the food web and returns to the soil during decomposition.geologic upliftingrainweathering ofphosphate from rocksrunoffsedimentationforms new rocksleachingphosphate in solutionanimalsplantsdecomposersphosphatein soilPhosphorus leaches into groundwater from the soil and is locked in sediments.Both mining and agriculture add phosphorus into the environment.