2Ecologists Study Relationships Interactions and InterdependenceEcology – the scientific study of interactions among living things and their surroundingsBasically, ecology is the study of nature’s houses. It can involve anything from single cells to entire planets.
3Ecologists Study Relationships Biosphere - part of a planet (the earth) in which life exists including land, water, and airA biosphere is the largest of the “houses” in a biosphere.For the earth it can extend from 8 km above the earth to 11 km below the surface of the ocean
4Ecologists Study Relationships Populations – individuals that live in the same areaSpecies – a group of individuals that can interbreed
5Ecologists Study Relationships Communities – assemblages of different populations that live togetherCommunities are within the ecosystem (Ex. A reef in the ocean)
6Ecologists Study Relationships Ecosystem – a collection of all organisms that live in a particular place with their nonliving, or physical environmentScientists often study species, populations, or communities in an ecosystem.the collection of components and processes that comprise, and govern the behavior of, some defined subset of the biosphere. The term is generally understood to refer to all biotic and abiotic components, and their interactions with each other, in some defined area, with no conceptual restrictions on how large or small that area can be.The breakdown is from largest to smallest – communities (assemblages of different populations) to populations (groups of individuals that belong to the same species and live in the same area) to species (A species generally consists of all the individual organisms of a natural population which are able to interbreed, generally sharing similar appearance, characteristics and genetics due to having relatively recent common ancestors.)
7Ecologists Study Relationships Levels of OrganizationBiome – a group of ecosystems that have the same climate and similar dominant communitiesWithin a biosphere is a biome.a biome is a major regional group of distinctive plant and animal communities best adapted to the region's physical natural environment, latitude, altitude, and terrain. A biome is made up of communities at stable steady state and all associated transitional, disturbed, or degraded, vegetation, fauna and soils, but can often be identified by the climax vegetation type.
8Ecologists Study Relationships Ecological MethodsObserving – first stepLong term studies more beneficial-ecological change takes timeSurveysDirectIndirectDetermining Population SizeCatch and releaseQuadrat SamplingEcologists can do visual surveys – direct or indirectDirect – used for species that are easy to follow; watch with the naked eye or with tools like binoculars or scopesIndirect – used for species difficult to track; use signs of presence like feces or urine or a recent killRadio Telemetry – used to monitor populations-animal fit with a radio collar that transmits a radio signal and used to track the animalCatch and release – used to determine population size – catch and mark members of population; then re-catch later and determine number of tagged to untaggedQuadrat sampling – dividing the plots into retangular frames-count the number of plants in each plot and then use a computer formula to determine the total number of plants in the entire area
9Ecologists Study Relationships Experimenting – used to test hypothesesCan do in the field or labLab-more control, not a true reflectionField-More accurate, difficult to determine cause and effect relationshipsLab-controlled setting used to focus on a very specific part of the ecosystemField-performed where the organism lives
10Ecologists Study Relationships Modeling – gain insightComputersMathematical modelsUse actual data to simulateData collected using satellite technology
11Biotic and Abiotic Factors Living and Non-living componentsBiotic - living factorsAbiotic - nonliving things
12Biotic and Abiotic Factors BiodiversityThe assortment, or variety of living thingsDependent on temperature, moistureKeystone Species – species that have a large impact on ecosystemsRainforests cover less than 7% of the earth’s surface, but contain 50% of the earths plant and animal speciesBeavers are a keystone species-they build dams which reduce water flow, which allows a greater variety of fish to live in the pond-fish attract birds such as herons and kingfishers-insects live in the trees-these insect attract other birds-shrubs grow on the edges of ponds attracting even more birds-animals that prey on bird eggs or the birds themselves are attracted to the area
13Energy in Ecosystems Producers – organisms that make their own food Autotrophs – organisms that use energy from the sun or chemicals to make foodAll the energy on earth comes from the sun.Only 1% of the energy that comes from the sun that reaches the earth is used by living things for energy.
14Energy in Ecosystems Energy from the sun Photosynthesis – Autotrophs use light energy to power chemical reactions that make energyUses CO2Makes O2 and CarbsOn land, plants are the main autotrophs.In the water, algae is the main photosynthesizer. There are some baceteria (cyanobacteria).Cyanobacteria are major producers in the ocean producing oxygen.
15Energy in Ecosystems Life without light One such bond is hydrogen sulfide, or iron monosulfide.Life without lightChemosynthesis – Use chemical energy to make carbohydratesBacteria deep in the ocean
16Energy in EcosystemsConsumers – Organisms that need other organisms for their energy and food supplyThese are also referred to as heterotrophs
17Food Chains and Food Webs Feeding RelationshipsFood Chains – A series of energy transferring steps
18Food Chains and Food Webs Types of heterotrophsHerbivoresEnergy from eating plantsCarnivoresEnergy from eating animalsOmnivoresBoth plants and animalsDetritivoresFeed on the remains of dead matterDecomposersBreak down organic matter for energyHerbivores – cows, catepillarsCarnivores – snakes, dogs, owlsOmnivores – humans, bears, crowsDetrivores – mites, earthworms, snails, crabsDecomposers – bacteria and fungi
19Food Chains and Food Webs SpecialistConsumer that primarily eats one specific organismGeneralistHave a varying dietSnail kites eat only apple snails for food
20Food Chains and Food Webs Trophic Levels – Each step in a food chain or webFirst level is producersSecond level on is consumers-usually herbivoresTertiary consumers are usually carnivoresEach consumer depends on the trophic level below it
21Food Chains and Food Webs Food Webs – Feeding relationships among many organisms in an ecosystem form a network of interactionsDecomposers will convert the dead plant material to detritus - is non-living particulate organic material (as opposed to dissolved organic material). It typically includes the bodies of dead organisms, fragments of organisms or faecal material, and is normally colonised by communities of microorganisms which act to decompose (or remineralize) the material.
22Cycling of Matter The Hydrological Cycle (Water Cycle) Evaporation – Water changes from a liquid to a gasTranspiration – Evaporation from the leaves of a plantThe water we need cycles between the ocean, atmosphere, and land.Water is evaporated from the ocean. It can also enter the atmosphere by a process called transpiration from plantAs the water vapor rises due to heating from the sun, it eventually begins to cool and condensation occurs.
23Cycling of MatterClouds form from tiny drops of water collecting called condensation
24Cycling of Matter Recycling in the Biosphere Biogeochemical cycles The transforming of matter by biological systemsEnergy moves in a one way fashion – Nutrients recycleEnergy flows one way in a biosphere; matter is continuously recycled in and between ecosystems.Elements, compounds, and other forms of matter are passed from one organism to another and from part of the biosphere to another.The reason it continues to recycle through the biosphere is that organisms do not use up matter, they transform it. – It is either assembled into body tissues or excreted as waste.
25Cycling of Matter Nutrient Cycles Nutrient – All the chemical substances that an organism needs to sustain lifeNutrients cycle through an ecosystem just like a biogeochemical cycle.
26Cycling of Matter Oxygen Cycle Most organisms use oxygen need oxygen Plants release oxygenLiving organisms release carbon dioxide as a waste product
27Cycling of Matter The Carbon Cycle Carbon is passed on from one situation to another throughout the biospherePhotosynthesis uses CO2 to make carbsCarbs are eaten by other organismsOrganisms exhale CO2 during cellular respirationAll organisms eventually decay and the carbon is converted to coal or petroleumBurning things releases stored CO2 into the atmosphereRemember, carbon is one if not the most important element to living things – it makes the macromolecules we need to survive.
28Cycling of Matter The Nitrogen Cycle All organisms need nitrogen to make amino acidsWhat do amino acids make?Proteins78% of Earth’s atmosphereNitrogen gas (N2)Other types:Ammonia (NH3)Nitrate (NO3)Nitrite (NO2)Nitrogen fixation – N2 to NH3Denitrification - NO3 to N2There are many types of naturally occurring nitrogen.Although N gas is the most abundant gas in the atmosphere only a few select bacteria can actually use it directly. They are usually attached to the roots of plants called legumes.They convert nitrogen gas to ammonia through nitrogen fixationDenitrification releases nitrogen from dead plants back into the atmosphere
29Cycling of Matter The Phosphorus Cycle DNA and RNA need phosphorus This element does not go into the atmospherePhosphorus works its way through the food web
30Cycling of Matter Nutrient Limitation Ecologists look at the rate of production of producers – Primary ProducivityAvailability of nutrients can limit an ecosystemLimiting nutrientEcosystem limited by one nutrientNitrogen in the ocean is the limiting nutrient% nitrogenIf runoff causes a drastic increase in nitrogen, then an algae bloom occursFarmers apply fertilizer because of limiting nutrientsAlgae bloom becomes a primary producer
31Pyramid ModelsEcological Pyramids – diagram that shows how much energy is transferred at each trophic level
32Pyramid Models Biomass Pyramid Biomass – Total amount of living tissue in a levelRepresents the amount of potential food available at each trophic level
33Pyramid Models Energy Pyramid Only about 10 % of the energy is transferred to the next trophic levelMore levels means less energy at the last levelOne tenth of the solar energy captured by grasses ends up stored in the tissues of cows. Only 10% of 10% (1%) is transferred to humans that eat the cow.
34Pyramid Models Pyramid Numbers Shows how many individuals there are in each level