POPULATION INTERACTIONS How orgs interact in an ecosystem! What role are you up for?

What is a niche?

What does it mean to have a role in an ecosystem? NICHE :NICHE : –THE ROLE AN ORGANISM PLAYS IN ITS ECOSYSTEM –ONLY ONE SPECIES CAN OCCUPY A NICHE AT A TIME LEADS TO COMPETITION IF MORE THAN ONE SPECIES WANTS ROLELEADS TO COMPETITION IF MORE THAN ONE SPECIES WANTS ROLE SIMILAR SPECIES CAN COEXIST AS LONG AS THEY HAVE DIFFERENT NICHES!SIMILAR SPECIES CAN COEXIST AS LONG AS THEY HAVE DIFFERENT NICHES! –EX: p102 in RB – WARBLERS!

HOW CAN I REMEMBER THAT “NICHE” MEANS ROLE AND NOT SPACE? THINK OF A PLAY! EVERY ROLE NEEDS TO BE FILLED IN ORDER FOR THE PLAY TO WORK! IF MORE THAN TWO PEOPLE WANT A ROLE, THERE IS COMPETITION AND THE BEST WINS!

Food Chains and Food Webs: Brain Pop Video Food Chains and Food Webs: Brain Pop Video

What are the relationships in an ecosystem? FOOD CHAINSFOOD CHAINS –Illustrate relationships between predators and prey –Specific orgs are included –Let’s take a look!

What are the relationships in an ecosystem?

–Niches defined by how obtain food 1. Autotrophs (Producers): –Make own food (grass) Heterotrophs (Consumers):Heterotrophs (Consumers): 2. Herbivores: Eat plants (grasshopper) 3. Carnivores: Eat animals (snake) 4. Omnivores: Eat plants and animals (humans) 5. Scavengers: Eat dead things; life’s clean-up crew! (vultures) 6. Decomposers: life’s recyclers (bacteria and fungi)

What are the relationships in an ecosystem? Symbiotic relationships – Brain Pop VideoSymbiotic relationships – Brain Pop VideoBrain Pop VideoBrain Pop Video ARE YOU SQUEAMISH???ARE YOU SQUEAMISH???ARE YOU SQUEAMISH???ARE YOU SQUEAMISH??? –When orgs live in REALLY close quarters Parasitism:Parasitism: –Live off other orgs but USUALLY don’t kill them (some worms, ticks, fleas) VIRUSES on HUMANS!! Mutualism:Mutualism: –Orgs that both benefit (clownfish (NEMO!!) and sea anemone) Commensalism:Commensalism: –One org benefits, other isn’t affected either way (whale and barnacles)

What are the relationships in an ecosystem? FOOD WEBS:FOOD WEBS: –All food chains in an ecosystem are illustrated in a food web –How many food chains can you make from this food web?

Let’s talk energy! The fuel of life! Ask yourself: Where does our ultimate source of energy come from?Ask yourself: Where does our ultimate source of energy come from? –The sun of course! Ask yourself: Which orgs can harness sun’s energy and make food?Ask yourself: Which orgs can harness sun’s energy and make food? –Plants of course! Ask yourself: What happens to the plant’s energy when a herbivore eats it?Ask yourself: What happens to the plant’s energy when a herbivore eats it? Ask yourself: What happens to the herbivore’s energy when a carnivore eats it?Ask yourself: What happens to the herbivore’s energy when a carnivore eats it? Ask yourself: What happens to the carnivore’s energy when another carnivore eats it?Ask yourself: What happens to the carnivore’s energy when another carnivore eats it?

Energy Pyramid: Video Clip

What happens to energy in an ecosystem? Every organism uses energy to carry out life processesEvery organism uses energy to carry out life processes If an organism is eaten, it will give less energy to the predatorIf an organism is eaten, it will give less energy to the predator THEREFORE, ENERGY DECREASES AS YOU MOVE UP A FOOD CHAIN!THEREFORE, ENERGY DECREASES AS YOU MOVE UP A FOOD CHAIN! WE USE AN ENERGY PYRAMID TO SHOW THIS!WE USE AN ENERGY PYRAMID TO SHOW THIS!

ENERGY PYRAMID

RECYCLING NUTRIENTS Decomposers extract what little energy is leftDecomposers extract what little energy is left They return raw materials (nitrogen) back to soilThey return raw materials (nitrogen) back to soil Other orgs continually recycling carbon dioxide and oxygenOther orgs continually recycling carbon dioxide and oxygen ENERGY IS NEVER RECYCLED!ENERGY IS NEVER RECYCLED!