CHAPTER 3 Feeding Relationships

LEVELS OF ORGANIZATION REVIEW SPECIES POPULATIONS COMMUNITIES ECOSYSTEMS BIOME BIOSPHERE

REVIEW TERMS ECOLOGY: scientific study of interactions among organisms, between organisms, in their environment BIOSPHERE: the world (combining ALL parts of the world)

COMPARE and CONTRAST PRODUCERS vs. CONSUMERS P = use sunlight/chemicals to make own food/energy C = use other organisms for food/energy AUTOTROPHS vs. HETEROTROPHS A = AKA producer H = AKA consumer

TYPES OF PRODUCERS PHOTOSYNTHESIS—use sunlight to make carbohydrates (sugars) CHEMOSYNTHESIS—use chemicals to make carbohydrates (sugars)

TYPES OF CONSUMERS HERBIVORES: energy from only plants i.e. cows and deer CARNIVORES: energy from only animals i.e. tigers and dogs OMNIVORES: energy from both plants and animals i.e. humans and bears DETRITIVORES: energy from remains of plants and animals i.e. mites and crabs

TROPHIC LEVELS Energy levels in a food chain or food web Producers = always first trophic level Consumers = make up the second, third,etc. trophic levels Decomposers = the last trophic level Grass → Caterpillar → Hawk → Wolf → Mushroom Arrows represent the flow of energy from one organism to the next ProducerPrimary Consumer Secondary Consumer Tertiary Consumer Decomposer

FOOD CHAIN Energy transfer from one organism to another in a series of steps EXAMPLE: Grass → Caterpillar → Hawk → Wolf → Mushroom ProducerPrimary Consumer Secondary Consumer Tertiary Consumer Decomposer

FOOD WEBS More complex than food chain Shows relationships among many different animals in an area Where are the trophic levels in this figure?

ENERGY PYRAMIDS ENERGY PYRAMID: Shows the relative amount of energy available in each trophic level BIOMASS PYRAMID: Total amount of living tissue for each trophic level Represents the amount of food available in each trophic level PYRAMID OF NUMBERS: Number of organisms in each trophic level

Organisms use about 10% of energy from each trophic level The rest is lost as heat Biomass Numbers Energy

RULE OF 10 Only 10% of energy is transferred from one trophic level to the next. Example: It takes 100 kgs of plant materials (producers) to support 10 kgs of herbivores It takes 10 kgs of herbivores to support 1 kg of 1 st level predator

Symbiosis – “living together” Symbiosis Type Species ASpecies B Commensalism + (benefit)0 (neutral) Mutualism + (benefit) Parasitism + (benefit)- (harmed)