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Ecology. BIO 2215 Oklahoma City Community College Dennis Anderson. Ecology. Study of the interactions of living organisms with each other and their environment. Scales of Life Populations—All members of a single species that live together in a specified geographic region.
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Ecology BIO 2215 Oklahoma City Community College Dennis Anderson
Ecology • Study of the interactions of living organisms with each other and their environment
Scales of Life • Populations—All members of a single species that live together in a specified geographic region. • Communities—All species that potentially interact with one another, in a given region. • Ecosystems—Communities of living things and their nonliving environment. • Biosphere—Entire interactive collection of the Earth’s ecosystems.
Biosphere Population Ecosystem Organism Community
The Ecosystem: The Fundamental Unit of Ecology • Ecosystem—A self-sustaining community of organisms and the physical environment with which they interact. • Consist of biotic (living) and abiotic (nonliving) factors. • Depend on Sun for ultimate source of energy; there’s one-way flow of energy through an ecosystem. • Some nutrients and water are taken up by living organisms and then cycled back to the abiotic component of an ecosystem.
Producer • Produces food • Energy from sunlight converted into chemical energy • Plants • Algae
Consumer • Consume food by eating • Primary • Secondary • Tertiary
Decomposer • Decompose dead bodies and organic matter • Fungi • Bacteria
Pyramid of Numbers Consumer 1 Consumer 90,000 Consumer 200,000 Producers 1,500,000
Pyramid of Biomass Consumer 1 g/m2 Consumer 11 g/m2 Consumer 37 g/m2 Producers 809 g/m2
Man Cattle Alfalfa
Man Cattle Alfalfa Man Rice
1st trophic level 3rd trophic level 2nd trophic level 4th trophic level Secondary consumers (herbivore predators) producers (photosynthesizers) Primary consumers (plant predators) Tertiary consumers (carnivore predators)
kingfisher merganser otter great blue heron dipper garter snake steelhead roach stickleback newt caddis fly larva frog tadpole snail water scavenger beetle larva crayfish tuft midge blue-green algae diatoms green algae
Abiotic Components of an Ecosystem • Carbon • Nitrogen • Water • Temperature • Sunlight • Etc
THE CARBON CYCLE atmospheric CO2 5 burning of fossil fuels 1 photosynthesis respiration 2 respiration plants animals 4 3 fossil fuels dead organisms decomposition by bacteria and fungi
THE NITROGEN CYCLE bacteria in root nodules of plants, and in soil atmospheric N2 assimilation into animals assimilation into plants 2 5 denitrifying bacteria animal waste dead organisms 1 nitrogen fixation 3 decomposition by bacteria and fungi ammonia (NH3) ammonium NH4+) 4 nitrifying bacteria nitrate (NO3)
THE HYDROLOGIC CYCLE 90% 10% water vapor precipitation over land evaporation precipitation over ocean transpiration, evaporation surface runoff ocean groundwater groundwater runoff
Sun 1,000,000 Calories Producer 5,000 2,000 1,000 500 Consumer Consumer Consumer 200 Decomposer 6,700 20,000 5,000 10,000 1,000 2,000 500 300 Total 20,000
Energy • Does not cycle in an ecosystem • Usable energy lost at each trophic level • Sun is the source of energy
Habitat • Where an organism is found • Marine • Fresh water • Tree tops • Under ground • etc
Niche • How an organism obtains food and resources to survive • “occupation” • Black rhino feeds on leaves and woody plants • White Rhino feed on grasses and herbs
Competitive exclusion P. aurelia Population size P. caudatum Time (days) P. aurelia Resource partitioning Population size P. bursaria Time (days)
Territory: Area defended against others of the same species.
peak 16 peak 12 8 Song level 4 0 1200 OH 800 CH3 Testosterone level CH3 400 O 0 January April August December Month
Advantages of Group Living • Easier to detect predator • Easier to repel predator • Protect young • Easier to find food • Easier to find a mate
Disadvantages of Group Living • More competition • More disease
Dominance Hierarchy • Each member has a rank in the pack • Alpha—highest rank • Beta—second rank • Omega—lowest rank
Dominance Hierarchy • Reduces conflict • Promotes social order
Predators Benefit Prey • Prevent overpopulation • Remove weak and sick from population
Symbosis • Living together • Parasitism • Commensalism • Mutualism
Parasitism • Parasite benefits • Host harmed
Mutualism Both benefit
Commensalism • Shark and Remora • Remora benefits
Populations • Capacity to grow exponentially 2-4-8-16-32-64 128……1,000,000
Population Growth • Birth rate • Death rate • Example • Population of 100 • 10 births and 8 deaths • Rate of growth is 2%