PRINCIPLES OF ECOLOGY

Look out for these symbols! Write this down! Draw this! Partner talk Volume 0

WHAT IS ECOLOGY? Scientific study of the interactions among organisms and their environments.

ASPECTS OF ECOLOGICAL STUDY Biosphere: part of the Earth that supports life. Environment: non living and living surroundings. Abiotic factors: non living factors, light, soil. Biotic factors: living organisms interactions. Look at the picture. How do other living organisms affect the gold fish?

LEVELS OF ORGANIZATION IN ECOLOGY ORGANISM POPULATION COMMUNITY ECOSYSTEM BIOSPHERE

ORGANISM Complete individual, living being.

POPULATION -A group of one species of organisms that live together in the same place at the same time -Interbreed. -Share and compete for resources. -Adaptations may reduce competition.

COMMUNITY -A group of interbreeding populations in the same area at the same time. -Changes in one population affects another.

ECOSYSTEM -Composed of the interactions between organisms, and their surrounding abiotic factors. -Types: terrestrial, freshwater and saltwater.

BIOSPHERE -All portions of Earth where life exists. -Relationship between all of the ecosystems.

ORGANISMS IN ECOSYSTEMS -HABITAT: Where the organism lives. -NICHE: The role and position the species has in the environment.

Predator prey relationship

Living together of different species may aid survival. Symbiosis

LIVING RELATIONSHIPS PARASITISM + - PARASITISM + - Tomato hornworn caterpillar and braconid wasp eggs MUTUALISM + + MUTUALISM + + Ant and acacia tree COMMENSALISM + 0 COMMENSALISM + 0 Spanish moss and a tree

FEEDING RELATIONSHIPS ◦ Autotroph: ◦ Heterotroph : HERBIVO RE CARNIVO RE OMNIVORE SCAVENGER DECOMPOS ER PLANTS

CYCLES IN NATURE -Energy in an ecosystem is replenished by the sun. -Matter in an ecosystem has to be recycled. -Atoms making up organisms today are the same as those present when life on Earth began.

Water Cycle

The Water Cycle ◦Precipitation ◦Evaporation ◦Condensation ◦Transpiration ◦Runoff ◦Groundwater

Carbon Cycle Carbon Cycle Video Carbon Cycle Video

The Carbon Cycle Atmosphere Photosynthesis Respiration Wastes Soil Fuel Pollution

The Nitrogen Cycle  Amino acids and proteins  Atmosphere  Lightning  Bacteria  Waste  Runoff

Nitrification – oxidation of ammonia with O 2 to make nitrates -Nitrates are absorbed by plants and are used for protein absorption Denitrification – nitrate reduction to produce nitrogen

Nitrogen Fixing Nodules -The bacteria converts the nitrogen that can’t be used by the plants into a useable form. What kind of symbiotic relationship would this be?

Lightning -Lightning breaks nitrogen molecules and letting nitrogen combine with oxygen in the air forming nitrogen oxides. These dissolve in rain, forming nitrates, that are carried to the earth.

Nitrogen cycle

STOP ….WAIT A MINUTE…..

NUTRITION AND ENERGY FLOW

HOW ORGANISMS OBTAIN ENERGY -Producers: AUTOTROPHS make their own food -Consumers: HETEROTROPHS take their food in ready made ◦Carnivores: meat, hawk ◦Herbivores: plants, rabbit ◦Omnivores: meat and plants, bear ◦Scavengers: carrion and refuse, buzzard -Decomposers: breakdown and release nutrients from dead organisms, bacteria and fungi.

MATTER AND ENERGY FLOW IN ECOSYSTEMS -Food chain: Model used to show how matter and energy flows through an ecosystem. -Autotrophs  Heterotrophs  Decomposers -Usually 3-5 links. -10% of available energy reaches next link. Because energy is used/lost as heat at each link. Grass  rabbit  fox

Practice building food chains Click on the link below (or access build food chain activity from the wiki ecology page) and build all the food chains. mals/kidscorner/games/foodchaingame.htmhttp:// mals/kidscorner/games/foodchaingame.htm

FEEDING LEVELS - Trophic level: A feeding step in a food chain. (Animal may occupy more than one trophic level in an ecosystem.) 1st trophic level = green plant = producer 2nd trophic level = herbivore = primary consumer/1st order 3 rd trophic level = carnivore = secondary consumer/2nd order 4th trophic level = carnivore = tertiary consumer/3rd order 5th trophic level = carnivore = quaternary consumer/4th order

What is wrong with this diagram?

Food Web -Model showing all possible feeding relationships at each trophic level in a community. -Network of interlinked food chains.

WRITE 2 FOOD CHAINS IN THIS FOOD WEB

ECOLOGICAL PYRAMIDS -Shows how energy flows through an ecosystem. -Initial energy source is the sun. -Autotrophs/1st trophic level at base of all pyramids. -Three types

Pyramid of numbers -Based on population size at each trophic level. -Populations decrease at each successive trophic level but inversion is possible.

Pyramid of Energy -Based on the amount of energy available at each trophic level. -Only 10% of the energy is past to the next level. Decreases at each level by 90%, this energy is used or lost as heat.

Pyramid of Biomass -Shows mass of living material at each trophic level. -Decreases at each trophic level