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

What does it mean to have a role in an ecosystem? NICHE: NICHE: THE ROLE AN ORGANISM PLAYS IN ITS ECOSYSTEM THE ROLE AN ORGANISM PLAYS IN ITS ECOSYSTEM ONLY ONE SPECIES CAN OCCUPY A NICHE AT A TIME ONLY ONE SPECIES CAN OCCUPY A NICHE AT A TIME LEADS TO COMPETITION IF MORE THAN ONE SPECIES WANTS ROLE LEADS 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! 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 PEEPS WANT A ROLE, THERE IS COMPETITION AND THE BEST WINS!

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

What are the relationships in an ecosystem?

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

What are the relationships in an ecosystem? Symbiotic relationships Symbiotic relationships When orgs live in REALLY close quarters When orgs live in REALLY close quarters Parasitism: Parasitism: Live off other orgs but don’t kill them (some worms, ticks, fleas) Live off other orgs but don’t kill them (some worms, ticks, fleas) Mutualism: Mutualism: Orgs that both benefit (Clownfish and sea anemone) Orgs that both benefit (Clownfish and sea anemone) Commensalism: Commensalism: One org benefits, other neither harmed or benefitted (Whale and barnacles) One org benefits, other neither harmed or benefitted (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 All food chains in an ecosystem are illustrated in a food web How many food chains can you make from this 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! 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! 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?

What happens to energy in an ecosystem? Every organism uses energy to carry out life processes Every organism uses energy to carry out life processes If an organism is eaten, it will give less energy to the predator If 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 nutrients are left Decomposers extract what little nutrients are left They return raw materials (nitrogen) back to soil They return raw materials (nitrogen) back to soil Other orgs continually recycling carbon dioxide, oxygen, and nitrogen Other orgs continually recycling carbon dioxide, oxygen, and nitrogen ENERGY IS NEVER RECYCLED! ENERGY IS NEVER RECYCLED! Let’s look at p107 and p108 in RB! Let’s look at p107 and p108 in RB!