Chapter 3

1. Chapter 3 The Biosphere

2. Section 3-1: What is Ecology? Ecology - Study of interactions among organisms, between organisms, and their surroundings. The environment contains two factors: • Biotic Factors: all of the living things • Abiotic Factors: all of the nonliving items

3. Section 3-1: What is Ecology? What is the biosphere? 1. Part of earth where all life exists 2. It’s range is 11 km(6.83 mi) below the surface ocean to 8 km(4.97 mi) above the surface of the ocean.

4. Section 3-1: What is Ecology? What are the levels of organization? • Species- group of organisms that can breed & produce fertile offspring 2. Population - groups of organisms of same species living in same area 3. Community - groups of different populations living in same area 4. Ecosystem - all organisms that live in same area along with environment 5. Biome - group of ecosystems with same climate & similar dominant communities 6. Biosphere - highest level of organization; where all life exists

5. Section 3-1: What is Ecology? What are the methods used to study ecology? • Observing • Experimenting A. Setting up an artificial environment in the lab B. Conducted within the natural environment • Modeling A. Often based on mathematical formulas based on data collection. B. Models are used to make predictions

6. Section 3-2: Producers & Consumers What are primary producers/autotrophs? Organisms that make their own food from sun/inorganic chemicals They produce their food in two possible ways: • Photosynthesis: Use energy from the sun to make organic chemicals for energy;(i.e.plants; photosynthetic bacteria; plantlike protists; cyanobacteria) 6CO2 + 6H2O → C6H12O6 + 6O2 • Chemosynthesis: Capture energy from source other than sunlight; use energy within chemical bonds of inorganic compounds like CO2 & H2S from volcanic vents to make organic molecules ; (example: sulfur bacteria)

7. Section 3-2: Producers & Consumers What are consumers/heterotrophs? Organisms that can’t make their own food; they have to eat other organism for food/energy. There are five types of consumers: 1. Herbivores – only eat plants 2. Carnivores – eat animals/meat 3. Omnivores – eat both plants & animals 4. Decomposers – break down dead/organic matter; recycle nutrients (bacteria, fungus) 5. Detritivores- eat decaying stuff (worms)

8. Section 3-3: Energy Flow How does energy flow in an ecosystem? It flows in one direction, from the sun to producers, and then to the consumers and decomposers. What is a food chain? A simple series of who eats who.

9. Section 3-3: Energy Flow What is a food web? A complex interaction of all of the food chains in an ecosystem.

10. Section 3-3: Energy Flow What is a trophic level? 1. One step in the food chain or the food web. 2. Producers always occupy the first trophic level. 3. Consumers occupy every level after the first. 4. Primary consumers are always herbivores.

11. Section 3-3: Energy Flow What is an ecological pyramid? It is a model to show the amount of energy or matter in each trophic level. There are three types of ecological pyramids: • Energy Pyramid • Biomass Pyramid • Pyramid of Numbers The pyramid shape implies that there is less at each successive level.

12. Section 3-3: Energy Flow What is an energy pyramid? • Shows how much energy is available at each trophic level. • 90% of the energy is used by the metabolism of the organisms in that trophic level. • 10% is passed on to the next trophic level. • Each level has less and less energy available.

13. Section 3-3: Energy Flow What is a biomass pyramid? • Shows how much food is available at each trophic level. • There is less food available at each higher level. • Measured in g/m2

14. Section 3-3: Energy Flow What is a pyramid of numbers? • Shows the number of individuals at each trophic level. • Because there is less energy at each level, there will be less individuals able to survive.

15. Section 3-4: Cycles of Matter Key idea: Matter is recycled within an ecosystem & between different ecosystems. Recycling in the biosphere is done through the biogeochemical cycles. Types of biogeochemical cycles: • Water cycle • Nutrient Cycles: A. Carbon Cycle B. Nitrogen Cycle C. Phosphorus Cycle

16. Evaporation Transpiration Section 3-4: Cycles of Matter Water Cycle Condensation Precipitation Runoff Seepage Root Uptake

17. Section 3-4: Cycles of Matter CO2 in the air Carbon Cycle CO2 in ocean

18. Section 3-4: Cycles of Matter N2 in air Nitrogen Cycle NO3- & NO2- NH3 Nitrogen Fixation – some bacteria turn N2 into the useable forms of NO3- & NO2-. Denitrification – some bacteria convert nitrates into N2.

19. Section 3-4: Cycles of Matter Phosphorus Cycle: • Phosphorus is needed by living things to form DNA/RNA. • Phosphorus DOES NOT enter the atmosphere like C, O, & N.

20. Section 3-4: Cycles of Matter What is primary productivity? The rate at which producers create organic matter. What controls primary productivity? Availability of nutrients. This is why fertilizer is added by farmers to their fields. What is a limiting nutrient? A single nutrient that is scarce or slowly cycled through the ecosystem. For most land ecosystems, the limiting nutrient is nitrogen (N is required for protein production).

21. Section 3-4: Cycles of Matter What is an algal bloom? • Occurs when an aquatic ecosystem receives a large input of its limiting nutrient (phosphorus). • The rapid growth of algae can disrupt the balance of the ecosystem. Excess phosphorus from lawn fertilizer can cause this.