Ecology

How is Earth a living planet? How do we study it?

Ecology: Study of interconnectedness of living things. How organisms interact and depend on each other for survival How they interact with and affect their environments

What’s the Connection? Ex: Bee and Flower Ex: Squirrel and Oak tree Ex: Mosquitoes and Frogs Ex: Human driving a car and planet

Levels of Ecological Organization Ecologists study different levels within the environment Individual Organisms Populations Communities Ecosystems Biomes Biosphere

What might we study about… Organisms: Looks at behavior of individuals Only part of the story because individuals depend on each other for food, shelter and protection Ex: movements, feeding behavior, offspring produced, sleep cycles, migration patterns Ex: One white tailed deer

What might we study about… Populations: group of individuals of same species that live in same area and interbreed Ex: Herd of white tailed deer Look at how populations utilize resources. How large is the population? Is it increasing, declining? What diseases may be affecting it What are affects of pollution on population

Why is it a good adaptation in many species for the juveniles to consume a different food source and live in a different part of the environment? Adaptation to reduce competition for resources!

What might we study about… Communities: populations of different species that interact and inhabit the same environment. A change in one population in a community will usually change and affect the other populations Ex: Forest Community

How does an increase in hawk population affect the mouse population? What other affects would that have on other plant and animal species in the community?

What might we study about… Ecosystems: Communities of organisms interacting with each other and with their physical environment. Can involve hundreds of different species

Terrestrial Ecosystems: on land Ex: Forest, meadow, desert, taiga, tundra Aquatic Ecosystems: in fresh or salt water Ex: Freshwater: Ponds, lakes, rivers, streams Ex: Marine (salt): oceans

What are some of the effects of deforestation on tropical rainforest ecosystems?

Characteristics of a Balanced Ecosystem Constant source of energy (ex: sunlight) Population of organisms that can store that energy in a usable form (autotrophic “producers”) Flow of energy from one population to another Way for materials and nutrients to be recycled

Biomes: group of ecosystems with similar climates & typical organisms Tropical Grassland Tropical Rain Forrest Desert Tundra Temperate Deciduous Forest Taiga: Coniferous Forest

Biosphere: portion of planet that supports life, (land, water, air) A very thin layer of Earth’s total area, but it extends high into atmosphere and deep into oceans (ex: The peel of an apple)

Living and Nonliving Environment The physical environment and living environment are connected in many ways Some abiotic factors How might they affect life here?

Biotic and Abiotic Factors Biotic Factors: living things in an environment that affect other living things Ex: Predators, parasites, worms in soil, decomposers recycle materials Abiotic Factors: nonliving parts of environment that affect living things Light: intensity and duration (depends on latitude) Temp: varies with latitude and altitude Water: amount of precipitation Short Clips: Biotic and Abiotic Factors: http://www.youtube.com/watch?v=woSO0D94VGA&safe=active http://www.youtube.com/watch?v=7Wfs2L5IydY&safe=active

Resources that are available in the shortest supply Limiting Factors Resources that are available in the shortest supply Ex: Availability of food Amount of moisture in the desert Amount of usable nitrogen in soil

Energy Flow in Ecosystems All organisms need energy to power life’s processes Where does this energy come from? How is it transferred from one organism to another?

Trophic Levels Each step in a food chain or food web is called a trophic level. Primary producers are always in the first trophic level

Primary Producers (First Trophic Level) Autotrophs Utilize energy from either sunlight or chemical compounds to make their own food Usually at the base of a “food chain”

Capturing Energy Photosynthesis Chemosynthesis Captures light energy using special pigments Converts carbon dioxide and water into sugars Chemosynthesis Harnesses chemical energy from inorganic molecules such as hydrogen sulfide Ex: Bacteria in deep sea volcanic vents

(Second, Third, Forth Trophic Levels etc…) Heterotrophs Consumers (Second, Third, Forth Trophic Levels etc…) Heterotrophs Acquire energy and nutrients from eating other organisms Can’t make own food

Types of Consumers Herbivores: (Primary Consumers) eat plants

Carnivores: (Secondary Consumers) usually kill and eat other animals (often eat herbivores)

Scavengers: (Secondary/Tertiary Consumers) Eats dead animals (both herbivores and carnivores)

Omnivores: (Primary & Secondary consumers) Eat both plants and animals

Decomposers: (Saprophytes) Break down dead material at all levels of food chain

Food Chains and Food Webs Short Clip: http://www.youtube.com/watch?v=3Bn7wdCP2v4&safe=active

Food Chains: series of steps in which organisms transfer energy by eating and being eaten.

Food Webs: show more complex feeding relationships and how they are interrelated Link together all the food chains in an ecosystem

Food Webs

Importance of Decomposers: Eat both producers and consumers Always the final consumer in any food chain or web Help return nutrients from dead material back to environment Without them nutrients would remain locked within dead organisms Recyclers! Decomposers: http://www.youtube.com/watch?v=Z6V0a_7N1Mw&safe=active Rabbit decomposition: http://www.youtube.com/watch?v=jrSHku6-LFo&safe=active

Pyramids of Energy Show relative amount of energy available at each trophic level On average only 10% of the energy is transferred to the next level. Most energy available at bottom

10% Rule Part of the energy is lost as heat or is used by organism to carry out life functions. Some food is not completely digested

Pyramids of Biomass Shows the total amount (mass) of living organic matter available at each level.

Pyramid of Numbers Shows relative numbers of organisms at each trophic level

How and Where Organisms Live Niche: the role a species plays in it’s community How it uses and affects its environment. What it feeds on Where it lives What preys on it Ex: Grass = producer Mushroom = decomposer Centipede = predator Worms = burrow through soil eating organic material

Habitat: where an organism lives it’s life Ex: burrow, cave, lake, forest, soil Although several species may share a habitat, the food, shelter and other resources are divided into separate niches Distinct behaviors have developed to reduce competition for available resources

Ex: Decaying Log has Many Niches Animals feed in different ways on different materials Millipede: eats decaying leaves, Worm: eats organic material in soil, Centipede eats other insects

Competition: arises when niches overlap More than one species has same requirements Compete for same resources Organisms have evolved to be specialized and adapted to exist in their specific niche in an ecosystem

Interspecific Competition: between different species for same niche and resources Intraspecific Competition: between same species for same niche and resources

Niche Clips: http://www.youtube.com/watch?v=6-aGxYTUPu0&safe=active http://www.youtube.com/watch?v=z3eDLQym9qo&safe=active

Food Chain Song: http://www.youtube.com/watch?v=TE6wqG4nb3M&safe=active Summary of Key Terms: http://www.youtube.com/watch?v=YvZlooi5_kE&safe=active Ecosystems and biomes: http://www.youtube.com/watch?v=dTaWsFct32g