Download
1 / 34
340 likes | 345 Views
Goal : Understanding Ecosystems and Bioshperes. Do Now : 1. What is the difference between a food web and a food chain? 2. Define producer and consumer Obj : SWBAT understand how different biomes function
E N D
Goal: Understanding Ecosystems and Bioshperes • Do Now: • 1. What is the difference between a food web and a food chain? • 2. Define producer and consumer • Obj: SWBAT understand how different biomes function • Anticipatory Set: If you could pick any where in the world to vacation, where would it be and why?
Today’s Agenda: • 1. take Cornell Notes from power point and define new vocabulary for the chapter • 2. Define ALL biomes in power point • 3. complete ALL “Biogeochemical Cycles” • (we will do this together in class)
How do Ecosystems Work?Chapter 28 Honors BioChapter 22 Lab Bio Producers and Consumers
PRODUCERS • Autotrophs—include plants and some kinds of protists. • Most capture energy from the sun to make their own food (sugar) • Some bacteria make food from inorganic molecules—this is called chemosynthesis.
Continue… • In terrestrial (land) ecosystems—plants are the major producers. • In aquatic ecosystems—photosynthetic protists (algae) and bacteria are the major producers.
Continue… • Producers make sugar (glucose) from the sun. Producers use some of the sugar for their own needs. Such as cellular respiration, maintenance and repair. • Any extra sugar goes to growth or reproduction. This extra sugar or organic material is referred to as Biomass. • Only energy stored as biomass is available to other organisms in the ecosystem.
Continue… • The rate at which biomass accumulates is called net primary productivity. • A tropical rain forest can have a 25 times greater rate than a desert of the same size.
CONSUMERS • Heterotrophs are consumers. They cannot make their own food. This includes animals, most protists, all fungi, and many bacteria. • They get their energy from consuming organic molecules made by other organisms.
Consumers • Consumers can be grouped by the type of food they eat: • Herbivores eat producers. Antelopes eat grass. • Carnivores eat other consumers. Lions eat antelopes. • Omnivores eat both producers and consumers. Humans eat salads and steaks.
Antelope! • !
Continue… • Detritivores are consumers that feed on the “garbage” of an ecosystem--recently died, fallen branches, animal wastes. Example vultures • Decomposers are detritivoreswhich breakdown dead tissues and wastes into simpler molecules that can be returned to the soil and water. Examples bacteria, fungi.
Vulture! • He’s cute!!
ENERGY FLOW • Whenever one organism eats another, energy is transferred. • Energy flows from producer to consumer. • An organism’s Trophic Level indicates its position in the sequence of energy transfer. • First trophic level: producers. Second trophic level: herbivores. Third trophic level: consumers that eat herbivores.
Continue… • Most ecosystems contain only three or four trophic levels. • A food chain is a single pathway of feeding relationships among organisms of an ecosystem that results in energy transfer. • Example: grass—meadow mouse—snake—hawk.
Continue… • The feeding relationships are too complex to be represented by a single food chain. • Many consumers eat more than one type of food. More than one species of consumer may feed on the same organism. • Thus the interrelated food chains of an ecosystem is called a food web.
Continue… • Roughly only 10 percent of the total energy consumed in one trophic level is incorporated into the organisms in the next level. • Example—deer eats 1000kcal of leaves—energy lost as 350kcal lost as urine, dung and other wastes: 480kcal lost as heat. Thus only 170kcal are stored as organic matter.
The end! • The low rate of energy transfer between trophic levels explains why ecosystems rarely contain more than a few trophic levels. • Example African safari: 1,000 zebras, gazelles, wildebeest, & other herbivores for every lion or leopard you see, & there are far more grasses, trees & shrubs than there are herbivores. Higher trophic levels contain less energy!
Terrestrial Ecosystems • 7 Biomes: • 1. tundra • 2. taiga • 3. temperate deciduous forests • 4. temperate grasslands • 5. deserts • 6. savannas • 7. tropical rain forest
