Introduction to Ecology 1. Ecology- is the study of how organisms survive and interact in their environment.

ECOLOGY 1. Ecology-Interaction of living and non living factors 2. Biosphere- Zone of earth that supports life

ECOLOGY Ecology actually means “study of the environment,” so I guess you could say that ecologists study animal households! 3.Ecosystems-Refers to all of the living and nonliving factors in an environment

4. Biotic factors - living things 5. Abiotic factors - nonliving things 6. Communities - all the living things in a certain area 7. Population - same species in the same area 8. Habitat- where an organism lives 9. Niche- role, what an organism does.

10.Nitrogen fixation - bacteria transforms atmospheric nitrogen to a form usable to plants (lightning does this, too!) N2 --> NO3 -1 11.Denitrification – other bacteria break down nitrogen compounds and release nitrogen gas to the air N2 – atmosphere NO3 -1 – usable by plants (nitrate)

ENERGY AND THE ENVIRONMENT Sunlight- major source of energy Organisms are classed according to how they get food Producers – (Autotrophs) Makes its own food. Ex: plants & algae

Consumers – (Heterotroph) gets food from other sources. Ex: animals Herbivores – eat plants (autotrophs) Carnivores- eat meat (heterotrophs) Omnivore- eats plants & animals (heterotrophs)

Primary Consumer – eats plants Secondary Consumer – eats primary consumer Tertiary Consumer – eats secondary consumer Limiting Factor – The thing that is in short supply Organisms may occupy several different feeding levels. Ex: Bear

Decomposers – (heterotroph) feed on dead organisms Decomposers – (heterotroph) feed on dead organisms. They break down nutrients into compounds Ex: Bacteria & Fungi Scavenger – Feed on the recently dead. Ex: Vulture, crows

Food Chain – Model of flow of energy through organisms of an ecosystem Example of a food chain: Sun  _____ _____ _____ Energy is not recycled. Therefore sunlight must continue to flow

Who’s the Greatest Carnivore ? Food Web – combination of many food chains. Best model of energy flow in an ecosystem Draw an example of a food web on the back of your notes Food Chain Who’s the Greatest Carnivore ?

FOOD AND ENERGY LEVELS Trophic Level = feeding level Energy Pyramid – Animals only gain 10% of the energy from the food they eat . The rest is used by that animal for life processes or released as heat.

FOOD AND ENERGY LEVELS bluejays 10 100 grasshoppers grass 1000

RELATIONSHIPS IN AN ECOSYSTEM Symbiosis = Interactions among different kinds of organisms 4 Types of Symbiosis Predation –

RELATIONSHIPS IN AN ECOSYSTEM Symbiosis = Interactions among different kinds of organisms Predation – one kills another for food. Predator/Prey Ex: __________

3 Types of Symbiosis 1. Parasitism – one benefits, one harmed. Parasite/Host Ex: ______________

2. Mutualism – Both benefit Ex: ______________________ 3. Commensalism – one benefits, one is unaffected (neither helped nor harmed) Ex: ____________________

Population = same species in a given area POPULATION GROWTH Population = same species in a given area Exponential Growth – (J- curve) Example: Human population time  Population 

LOGISTIC GROWTH (S-curve) Example: Deer population B A Time  Steady State = Zero Population Growth

Carrying Capacity = # of organisms the environment can sustain Limiting Factors – factors that control population growth Example: food, water, habitat

Density-dependent limiting factors = affect large, crowded populations Competition – compete for same resource Predation - predation prey

Parasitism – crowding helps parasites travel from host to host Crowding – restricts room to hunt nest. Increases fighting, causes stress. Stress weakens immune system Density Independent Factors – affects populations regardless of their sizes. Ex: earthquakes

Section 4.1 Summary – pages 91-99 Predation affects population size The data in this graph reflect the number of hare and lynx pelts sold to the Hudson’s Bay Company in northern Canada from 1845 through 1935. Lynx and Hare Pelts Sold to the Hudson’s Bay Company Lynx Hare Number of organisms(in thousands) Times (in years) Section 4.1 Summary – pages 91-99

Draw a population cycle

VANISHING SPECIES Biodiversity – refers to the variety of life in an area * Large islands have greater biodiversity than small islands (if everything else is the same) Importance – Biodiversity brings stability Species loss affects the existence of other species

LOSS OF BIODIVERSITY Threatened species-species of declining numbers Endangered species-numbers are very low, extinction is possible Extinction – no longer exists

Threats to Biodiversity *1. Habitat Loss - #1 threat. Ex: rain forest becomes pasture Habitat fragmentation- separation of wilderness areas from the rest. Ex: roads

Threats to Biodiversity *1. Habitat Loss - #1 threat. Ex: rain forest becomes pasture Habitat fragmentation- separation of wilderness areas from the rest. Ex: roads

Threats to Biodiversity 3. Biotic Issues-some species need large spaces. Ex: migration 4. Abiotic Issues – climate can be changed with the removal of trees.

5. Habitat degredation – damage to a habitat by pollution a. Air pollution#1 source=burning fossil fuels Acid rain = low pH from SOx (coal) and NOx (cars) Ground Level Ozone & CFCs (chlorofluorocarbons) in refridgerators destroys atmospheric ozone

b. Water pollution  excess fertilizers, animal waste & silt c. Land pollution  trash, pesticides (DDT banned in 1972) Introduction of Exotic species – These are non-native species Ex: rats, goats *Rachel Carson-author of Silent Spring

Conservation of Biodiversity Conservation Biology-explores ways to protect biodiversity Legal Protection of species- U.S. Endangered Species Act- 1973 protects threatened & endangered species

2. Preserving Habitats- protecting entire ecosystems 2. Preserving Habitats- protecting entire ecosystems. May be best way to conserve species First National Park 1872 6% of Earth is parks Sustainable Use-philosophy of using resources in ways without harming the ecosystem

4. Habitat Corridors-leaving natural strips that allows for migration & connects fragmented lands 5. Reintroduction programs-releasing species in an area where they once lived. 6. Captivity- species may survive by being kept by people.

Biomagnification

Biomagnification of Insecticides Biomagnification of Mercury the accummulation and magnification of toxic materials at each step of a food chain. Ex: DDT & eagles Biomagnification of Insecticides Biomagnification of Mercury

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