2 3–1 What Is Ecology? Objectives: Describe the study of Ecology Explain how biotic and abiotic factors influence an ecosystemDescribe the methods used to study ecology
3 What is ecology?Ecology is the scientific study of interactions among organisms and between organisms and their physical environment
4 Interactions and Interdependence Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live.The interdependence of life on Earth contributes to an ever-changing, or dynamic, biosphere.
5 BiosphereThe biosphere contains the combined portions of the planet in which all of life exists, including:landwaterair, or atmosphereThe biosphere extends from about 8 kilometers above Earth's surface to as far as 11 kilometers below the surface of the ocean.
6 Levels of Organization To understand relationships within the biosphere, ecologists may study these ecological levels of organization:OrganismPopulationCommunityEcosystemBiomeBiosphere
7 Organism: Individual member of a species- group of organisms that are physically similar and can interbreed with one another to produce fertile offspringLiving things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.BisonCopyright Pearson Prentice Hall
8 Group of organisms of the same species living in the same area PopulationGroup of organisms of the same species living in the same areaLiving things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.Bison herdCopyright Pearson Prentice Hall
9 All populations that live together in a defined area CommunityAll populations that live together in a defined areaLiving things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.Hawk, snake, bison, prairie dog, grassCopyright Pearson Prentice Hall
10 All the populations and the physical surroundings EcosystemAll the populations and the physical surroundingsLiving things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.Hawk, snake, bison, prairie dog, grass, stream, rocks, airCopyright Pearson Prentice Hall
11 Ecosystem includes the biotic (living) and abiotic (nonliving) factors
12 BiomeGroup of similar ecosystems that share similar climates and dominant communities of organisms (e.g tall grasses)Living things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.Prairie biomeCopyright Pearson Prentice Hall
13 The part of Earth that contains all ecosystems BiosphereThe part of Earth that contains all ecosystemsLiving things may be studied on many different levels. The largest and most complex level is the biosphere. The smallest level is the molecules that make up living things.Copyright Pearson Prentice Hall
15 Methods Ecologists Use All of these approaches rely on the application of scientific methods to guide ecological inquiry
16 Ecological ModelsModeling- used to explain large-scale phenomena too large or too complex to study with observation or experiments aloneExamples:Food websBiogeochemical cycle diagramsCarbon cycle affects all levels of ecological organization up to the biosphere. A model helps make all aspects of the phenomenon observable
17 3-2 Energy, Producers, and Consumers Objectives:Define primary producersDescribe how consumers obtain energy and nutrients
18 Role of Primary Producers Energy is required for all life processesEnergy flows from the sun or inorganic compounds to autotrophs (producers).Heterotrophs (consumers) eat producers to get energy.Without a constant input of energy, living systems cannot function.The primary source of energy on Earth is the sun
19 Role of Primary Producers Autotrophs – “self feeder”Most use sunlight to create carbohydrates via photosynthesisOxygen created as a byproductEx: Plants, some protists (algae) and some bacteriaSome bacteria create organic compounds from inorganic chemicals in a process called chemosynthesisLive in remote places.Also can make carbohydrates and oxygen
21 Role of Primary Producers Autotrophs (plants, some bacteria) are called primary producersthe first producers of energy-rich compounds that are later used by other organismssome of their self-made energy is stored and available to other organisms that eat themMmm…this plant is delicious.
22 Role of Consumers Heterotroph – “different feeder” Cannot harness energy directly from the physical environment.Must ingest food to obtain energyEx: animals, fungi, some bacteria, some protists
23 Energy Flow: Role of Consumers There are many different types of heterotrophs.Herbivores eat plants.Carnivores eat animals.Omnivores eat both plants and animals.Detritivores feed on plant and animal remains and other dead matter.Decomposers, like bacteria and fungi, break down organic matter.Scavengers consume carcasses of animals that have been killed by other predators
24 Ch 3-3 Energy Flow in Ecosystems Objectives:Trace the flow of energy through living ecosystemsIdentify 3 types of ecological pyramids
25 Food ChainsEnergy flows through an ecosystem in one direction from producers to consumersA food chain is a series of steps in which organisms transfer energy by eating and being eatena single path of energy transfer in an ecosystemfrom the sun or inorganic compounds (not usually pictured) autotrophs (producers) various heterotrophs (consumers).Phytoplankton, floating algae, are primary producers in aquatic food chains
26 Energy Flow: Food WebsA food web is the complex network of feeding relationships in an ecosystemlinks all the food chains in an ecosystem togetherCan provide information to determine the type of heterotroph
28 Energy Flow: Trophic Levels Each step in a food chain or food web is called a trophic level.Producers make up the first trophic level.Consumers make up the second, third, or higher trophic levels.Each consumer depends on the trophic level below it for energy.A single organism may occupy more than one trophic level
30 Ecological PyramidsAn ecological pyramid is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
31 Ecological Pyramids: Energy Pyramids Only about 10 percent of the energy available within one trophic level is transferred to organisms at the next trophic level.
32 Ecological Pyramids: Energy Pyramids Organisms use some of the energy for their own life processesMost is lost to the environment as heat
33 Ch 3-4 Cycles of Matter Objectives: Describe how matter cycles among the living and nonliving parts of an ecosystemDescribe how water cycles through the biosphereExplain why nutrients are important to living thingsDescribe how the availability of nutrients affects the productivity of ecosystems
34 3-3 Cycling Matter Recycling in the Biosphere Matter is recycled within and between ecosystems.Matter moves through an ecosystem in biogeochemical cycles
35 Biogeochemical Cycles 4 cycles of interest:watercarbonnitrogenphosphorusNutrients are all the chemical substances that an organism needs to sustain life.required to build tissues and carry out essential life functionsCirculated throughout biosphere in biogeochemical cycles
40 Nitrogen CycleNitrogen is needed for protein and nucleic acid synthesis78% of Earth’s atmosphere is nitrogen gas (N2)Nitrogen containing products that can be used by plantsAmmonia (NH4)Nitrate ions (NO3-)Heterotrophs can only get nitrogen by eating other organisms
41 Bacteria and the Nitrogen Cycle Converting nitrogen gas into ammonia is called nitrogen fixationOnly certain species of bacteria can do thisFound living on plant roots or in soilOther nitrifying bacteria convert ammonia into nitratesA process called ammonificationPlants use the converted products (NH4 and NO3-) to make plant proteinsA process called assimilationSome bacteria convert nitrates into nitrogen gas (denitrification).Like in phosphorus and carbon cycles, bacteria act as decomposers returning nitrogen back to soilRoot nodules on a legume
43 Phosphorus CyclePhosphorus is important for the formation of DNA and RNA molecules.Plants assimilate phosphorus that is in the soilAnimals get phosphorus by eating other organismsPhosphorus is not very common and does not enter the atmosphere, instead it is found mostly on land in rock and soil.
44 Carbon Cycle Required for photosynthesis Released during the process of cellular respiration
45 Nutrients and Productivity The primary productivity of an ecosystem is the rate at which organic matter (biomass) is created by producers.One factor that controls the primary productivity of an ecosystem is the amount of available nutrients
46 Nutrients and Productivity When a limiting nutrient, phosphorus, nitrogen, etc., is introduced it can cause bursts productivityEx: algal bloomsCompared to land, open oceans are nutrient poor
47 Energy and Matter in Ecosystems: The Main Idea Energy flows in one directionMatter is transferred and recycled between the biotic and abiotic parts of ecosystems
48 NicheAn organism’s niche includes how it survives and reproduces in its environment. This includes:Place in food webEnvironmental conditions it needs to surviveType of food it eatsHow it obtains foodOther species that use it as foodWhen and how it reproducesWhat is the niche of a bullfrog?
49 NicheCompetitive Exclusion Principle - no two species can occupy the same niche in the same habitat at the same timeSharing a niche results in competition in nature often results in winner and loser – losing organism fails to surviveDifferent species can occupy similar niches.Resource partitioning helps organisms with similar niches avoid competition
50 Warbler Niches Cape May Warbler Feeds at the tips of branches Bay-Breasted WarblerFeeds in the middlepart of the treeCape May WarblerFeeds at the tips of branchesnear the top of the treeSpruce treeYellow-Rumped WarblerFeeds at the lower parts of the tree and bases of middle branches
51 Community Interactions Competition- same or different species attempt to use an ecological resource in the same place at the same time
52 Community Interactions Predation - one organism captures and feeds on another organismPredator – the one killing and eatingPrey – the food
53 Community Interactions-Symbiosis Symbiosis- an interaction between two species living close togetherThree types:Parasitism – one is harmed (host), one benefits (parasite)Mutualism – both benefitCommensalism – one is neutral, one benefits