Ecology Notes 2 Symbiotic Relationships Food Webs Food

Ecology Notes #2 Symbiotic Relationships Food Webs Food Chains

SYMBIOTIC RELATIONSHIPS

Symbiotic Relationships § Definition: Relationship where 2 species live closely together. § The word symbiosis can be broken down into two parts to determine its meaning. § sym means together (like in the words sympathy and symphony) § bio mean life (like in the words biology and biome)

Types of Symbiosis Relationship Type Species A Species B Mutualism + + Commensalism + 0 Parasitism + -

Mutualism § Relationship where BOTH species BENEFIT! § A + / + relationship. § Think of a normal friendship where both friends gain something from the friendship.

Mutualism Example. . . Sharks are cleaned by a little fish known as a Remora. The shark never eats them since they clean bacteria off of the shark. Since both species are helped, this is mutualism.

Commensalism § Commensalism is where one species benefits while the second species remains unaffected. § A + / 0 relationship § Think of a friendship where one of the friends benefits while the other doesn’t change. Barnacles adhering to the skin of a whale

Parasitism § Parasitism is the situation where one organism benefits while the other is harmed. § A + / - relationship. § Think of a friendship where you might feel used by your friend.

• Predation- an interaction in which one organism captures and feeds on another organism.

§ Competitionoccurs when organisms attempt to use an ecological resource in the same place.

FOOD WEBS and FOOD CHAINS

Eat or be eaten § Here are some important terms that will help you describe interactions in a food web. 1. Producer (autotroph) § *can make its own food § *forms the base of the food web

Mmmmm…delicious. 2. Consumer (heterotroph) § cannot make its own food There are several words that describe consumers… § Prey: the hunted § Predator: the hunter § Scavenger: eats dead things § Herbivore: eats plants § Carnivore: eats animals § Omnivore: eats both plants and animals

Hey, you gonna eat that? 3. Decomposer § Breaks down dead organisms § Examples: bacteria, maggots, fungi, worms § They complete the circle of life by returning nutrients to the soil 4. Detritivore § Feeds on dead organic material

Food Chain § A food chain is the sequence of who eats whom in a biological community (an ecosystem) to obtain nutrition. A food chain starts with the primary energy source, usually the sun!!

Food Chain Producer Primary Consumer Secondary Consumer ARROWS represent ENERGY FLOW! Tertiary Consumer Herbivore Carnivore Autotroph Omnivore

Tertiary Consumer Secondary Consumer Primary Consumer Producers

§ Primary producers (organisms that make their own food from sunlight and/or chemical energy from deep sea vents) are the base of every food chain - these organisms are called autotrophs. § Primary consumers are animals that eat primary producers; they are also called herbivores (plant-eaters). § Secondary consumers eat primary consumers. They are carnivores (meat-eaters) and omnivores (animals that eat both animals and plants). § Tertiary consumers eat secondary consumers. § Quaternary consumers eat tertiary consumers. **Food chains "end" with top predators, animals that have little or no natural enemies**

Food webs § All organisms need FOOD to survive! § Food webs show what eats what. § ARROWS represent ENERGY FLOW!!!

What is this?

Trophic Levels § Group of organisms whose energy source is the same number of steps away from the sun or the position in a food chain.

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

Carnivores 0. 1% Tertiary Consumers Carnivores 1% Secondary Consumers Herbivores 10% Primary Consumers Producers and Decomposers 100%

Biomass - Dry weight of tissue and other organic matter found in a specific ecosystem - When trophic levels are shown in an energy pyramid, each higher level on the pyramid contains only 10% of the biomass found in the level below it.

18 Energy used by producers in a Used by producers grassland food web is provided by F sunlight This is a process, not an energy source. G photosynthesis H and J are elements which are types of matter, not energy. H oxygen J carbon dioxide So our answer should be: F

In this food chain, the spiders are -§ A producers § B primary consumers § C competitors § D secondary consumers

In this food pyramid, which level contains the greatest amount of energy? § § § A Tertiary consumers B Secondary consumers C Primary consumers D Producers

About 10% of the energy at one trophic level is passed to the next level. What usually happens to the energy that is not passed to the next trophic level or used to carry out life processes? § § A It is given off as heat. § B It is stored as vitamins. § C It is used in reproduction. § D It is used in protein synthesis.

Which organisms in this food web can be described as both primary and secondary consumers? § § § F Hawks G Weasels H Raccoons J Mice

Now, practice making food webs on the whiteboard. Label the producers, primary consumers, secondary consumers, tertiary consumers, herbivores, carnivores