Semester 2, Day 2 Ecosystem & Energy

Agenda Turn in Cornell Notes & Question Responses Biodiversity Quiz Ecosystem Lecture 4 Minute Break Reading/Work Time Hand Quizzes back and review

Turn in Cornell Notes and Question Responses Order Cornell Notes 34.1 Cornell Notes 34.2 Cornell Notes 34.3 Cornell Notes 34.4 Responses to Section 34.1-34.4 and Chapter 34 Review Make sure that your name is on your notes/responses Initial each following page Keep the papers together, fold the corner if not stapled

Biodiversity Quiz Complete the quiz silently When you are finished, place quiz facedown on desk When everyone is finished, pass quizzes forward

Ecosystem Changes How do certain changes affect an ecosystem? Climate Changes Temperature, flooding, global warming, freezing Can eliminate entire biological communities New communities will repopulate the area  NEW ECOSYSTEM! From natural resources (volcanoes)

Ecosystem Changes How do certain changes affect an ecosystem? Human Activity Human-caused global warming, pesticides, deforestation, urban encroachment, endangered species, acid rain, water contamination, fossil fuels, dams for hydroelectricity, radioactive waste, oil spills, air pollution, soil erosion, salting roads, crop irrigation All of these can kill populations, resulting in the entire ecosystem being disrupted

Ecosystem Changes How do certain changes affect an ecosystem? Human Activity (cont.) Smallmouth Bass Dies from Lack of Food EFFECT Spirogyra Population Explodes EFFECT Daphnia Kill with Pesticides CAUSE Bluegill Dies from Lack of Food EFFECT

Ecosystem Changes How do certain changes affect an ecosystem? Introduction of Non-Native / Invasive Species Harmful No predators Displace native species Carry disease Population Size Caused by humans Example: Too many predators, prey die out, then predators die, and plants the prey ate grow out of control.

Population Size in Ecosystem BIRTH IMMIGRATION EMIGRATION DEATH Rates that increase population size Rates that decrease population size Organisms enter ecosystem Organisms enter ecosystem

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap between births and deaths. Births Gap gets bigger Therefore, population INCREASES Number of Organisms Deaths Time

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap between births and deaths. Births Gap gets smaller Therefore, population INCREASES Number of Organisms Deaths Time

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap between births and deaths. Births Gap stays the same Therefore, population INCREASES Number of Organisms Deaths Time

Energy Flow in an Ecosystem Autotrophs: produce their own food. 2 types: Autotrophs make ENERGY available for all other organisms in the ecosystem. Phototrophs Chemotrophs Organisms with chlorophyll Chlorophyll absorbs light energy for photosynthesis Converts light energy to food energy When sunlight is unavailable Hydrogen sulfide (H2S) or carbon dioxide (CO2) converted to organic (“life”) molecules. “self” “Light” “Chemical”

Energy Flow in an Ecosystem Heterotrophs: get energy by consuming other organisms. Note: Decomposers: secrete enzymes to break down dead matter & then absorb the nutrients (bacteria and fungi) Herbivore Carnivore Omnivore Detritivore Organisms that consume dead matter (any). Tend to be bugs. Organisms that consume only plants Organisms that consume only other heterotrophs Organisms that consume both autotrophs and heterotrophs AKA “Consumers”

Energy Flow in an Ecosystem Decomposers & Detritivores are similar, BUT DECOMPOSERS Secrete enzymes to break down Absorb nutrients Bacteria, Fungi DETRITIVORES Eat & digest Bugs (generally) *Note: Scavengers technically eat dead organisms, but will also eat live organisms Dead Matter

Arrow shows direction of ENERGY Energy Flow: Food Webs Food Chain: simple model; one-way energy flow Primary Producer  Primary Consumer  Secondary Consumer  Tertiary Consumer *Note: All primary producers are autotrophs All primary consumers are herbivores (a type of heterotroph) Higher consumers can be omnivores OR carnivores Arrow shows direction of ENERGY

Energy Flow: Food Web Food Web: Interconnected food chains; complex

Energy Flow: Ecological Pyramids Ecological pyramids: show relative amounts of energy, biomass, or # of organisms. Tertiary Consumer Secondary Consumer Primary Consumer Primary Producer Trophic Levels Template

Energy Flow: Ecological Pyramids Pyramid of Energy 0.1% 1% Energy 10% Energy 100% Energy Energy Lost as Heat (90%) Available Energy Decreases

Energy Flow: Ecological Pyramids Pyramid of Biomass (total mass of life @ each level) 1.5 g/m2 11 g/m2 37 g/m2 809 g/m2 Note: Mass/Area Available Biomass Decreases

Energy Flow: Ecological Pyramids Pyramid of Numbers (# of Organisms) 10,000 90,000 200,000 1,500,000 Population Size Decreases

4 Minute Break Stay on this floor, otherwise privilege will be revoked Be back in the class by ______.

Reading / Work Time Read Chapter 2 Do the Chapter 2 Assessment Questions #1-15, 17-24 Come show me your responses when you are finished. If you don’t finish, it is homework!

Reminder dp.davincischools.org/staff/blarkin