Chap 36 Ecosystems and Chap 36 Ecosystems and Conservation BiologyConservation Biology

36.1 Feeding 36.1 Feeding RelationshipsRelationships

• Every organism requires energy to carry out life Every organism requires energy to carry out life processes such as growing, moving, and processes such as growing, moving, and reproducing.reproducing.

• Producers:Producers:

• Convert light energy from sunlight to chemical Convert light energy from sunlight to chemical energyenergy

• Consumers:Consumers:

• Obtain chemical energy from consuming other Obtain chemical energy from consuming other organismsorganisms

• Decomposers:Decomposers:

• Break down wastes and dead organismsBreak down wastes and dead organisms

How is energy passed between these organisms? How is energy passed between these organisms?

Flower takes in sunlightFlower takes in sunlight

Grasshopper eats flowerGrasshopper eats flower

Mouse eats grasshopperMouse eats grasshopper

Eagle eats mouseEagle eats mouse

What is this an example of?What is this an example of?

Food chain:Food chain:

Pathway of food transfer from one trophic level to Pathway of food transfer from one trophic level to another. another.

Trophic level:Trophic level:

Feeding levelFeeding level

ProducersProducersAlways on the bottom of the food chainAlways on the bottom of the food chain

Base for all food websBase for all food webs

If we had no producers, would anything live?If we had no producers, would anything live?

No!No!

Ex. Ex.

ConsumersConsumers• Herbivore:Herbivore:

• Only eats plantsOnly eats plants

• Carnivore:Carnivore:

• Only eats other organismsOnly eats other organisms

• Omnivore:Omnivore:

• Eats both plants and other organismsEats both plants and other organisms

ConsumersConsumers• Primary consumers (1Primary consumers (1stst level consumer): level consumer):

• Feeds directly on the producersFeeds directly on the producers

• Secondary consumers (second level):Secondary consumers (second level):

• Consumer that eats primary consumersConsumer that eats primary consumers

• Tertiary consumers (third level):Tertiary consumers (third level):

• Consumer that eats secondary consumers Consumer that eats secondary consumers

What can primary consumers only be?What can primary consumers only be?

HerbivoresHerbivores

DecomposersDecomposers• At each trophic level, organisms produce At each trophic level, organisms produce

waste and die.waste and die.

• The waste and remains of dead organisms is The waste and remains of dead organisms is called detritus.called detritus.

• Often called scavengers.Often called scavengers.

• Ex.Ex.

• Earthworms, crayfish, vultures etc. Earthworms, crayfish, vultures etc.

What is this? What is this?

Food WebFood WebFood web:Food web:

Pattern of feeding represented by interconnected and Pattern of feeding represented by interconnected and branching food chains. branching food chains.

https://www.youtube.com/watch?v=ysa5OBhXz-Q

36.2 Energy Flows 36.2 Energy Flows • Of the light energy that reaches plants what Of the light energy that reaches plants what

percentage is used for photosynthesis?percentage is used for photosynthesis?

• 1%1%

• Biomass: Biomass:

• Organic material manufactured by plantsOrganic material manufactured by plants

• Primary productivity:Primary productivity:

• The rate of which producers in an ecosystem build The rate of which producers in an ecosystem build biomass. biomass.

• Primary productivity determines the maximum Primary productivity determines the maximum amount of energy available to all higher trophic amount of energy available to all higher trophic levels.levels.

Which biome has Which biome has the most primary the most primary

productivity?productivity?DesertDesert

SavannaSavanna

Deciduous forestDeciduous forest

Rain forest Rain forest

Rain forestRain forest

Ecological PyramidsEcological PyramidsAs each consumer feeds, some energy is transferred As each consumer feeds, some energy is transferred from lower trophic levels to higher, but most energy in from lower trophic levels to higher, but most energy in the preys organismthe preys organism’’s biomass is lost. s biomass is lost.

Caterpillar eats a leafCaterpillar eats a leaf50% of the energy in the leaf passes as the caterpillars 50% of the energy in the leaf passes as the caterpillars waste.waste.

The caterpillar uses 35% of the energy from the leaf for The caterpillar uses 35% of the energy from the leaf for energy for itself.energy for itself.

Only about 15% of the leafs stored energy is turned Only about 15% of the leafs stored energy is turned into biomass for the caterpillar.into biomass for the caterpillar.

Energy PyramidEnergy PyramidEnergy pyramid:Energy pyramid:Shows the energy loss from one trophic level to another. Shows the energy loss from one trophic level to another.

An average of 10% of energy is converted to biomass in the An average of 10% of energy is converted to biomass in the next trophic level. next trophic level.

90% is lost as heat. 90% is lost as heat.

Energy PyramidEnergy Pyramid

Pyramid of numbersPyramid of numbersPyramid of numbers:Pyramid of numbers:

Shows the number of individual organisms in each Shows the number of individual organisms in each trophic level.trophic level.

Organized like energy pyramids.Organized like energy pyramids.

36.3 Chemical Cycles36.3 Chemical CyclesGeneral stepsGeneral steps

1. Producers incorporate chemicals from the nonliving 1. Producers incorporate chemicals from the nonliving environment into organic compounds.environment into organic compounds.

2. Consumers feed on producers, either using them as 2. Consumers feed on producers, either using them as energy or releasing them as waste.energy or releasing them as waste.

3. Organisms die and decomposers break them down 3. Organisms die and decomposers break them down and return to soil. and return to soil.

Carbon and Oxygen Carbon and Oxygen CycleCycle

1. Volcanoes, organisms, and cellular respiration 1. Volcanoes, organisms, and cellular respiration produces carbon dioxide.produces carbon dioxide.

2. Plants uses the carbon dioxide and produce oxygen.2. Plants uses the carbon dioxide and produce oxygen.

Nitrogen CycleNitrogen Cycle1. Bacteria convert nitrogen gas to ammonia through a 1. Bacteria convert nitrogen gas to ammonia through a process called nitrogen fixation. process called nitrogen fixation.

2. Other bacteria take the ammonia and produce 2. Other bacteria take the ammonia and produce ammonium though a process called nitrification.ammonium though a process called nitrification.

3. Plants absorb the ammonium and can be consumed 3. Plants absorb the ammonium and can be consumed by other organisms.by other organisms.

Organisms die and cycle repeats. Organisms die and cycle repeats.

Water CycleWater CyclePlants transpire, and water evaporates from bodies of Plants transpire, and water evaporates from bodies of water.water.

Condensation releases by precipitation back to the Condensation releases by precipitation back to the Earth.Earth.

Run off and groundwater go into bodies of water. Run off and groundwater go into bodies of water.

36.4 Human Activities36.4 Human ActivitiesHuman activities can affect chemical cycling by moving Human activities can affect chemical cycling by moving nutrients from one place to another.nutrients from one place to another.

Humans eat vegetables from different parts of the Humans eat vegetables from different parts of the country. country.

Human waste might be carried to the ocean in sewage.Human waste might be carried to the ocean in sewage.

Carbon Cycle ImpactsCarbon Cycle ImpactsBurning of wood and fossil fuels is one source of Burning of wood and fossil fuels is one source of carbon dioxide. carbon dioxide.

As nations industrialize and use wood, carbon levels As nations industrialize and use wood, carbon levels increase.increase.

What organisms use carbon dioxide to make oxygen?What organisms use carbon dioxide to make oxygen?

PlantsPlants

What is happening to trees and forests?What is happening to trees and forests?

Deforestation:Deforestation:

Clearing of forests for agriculture. Clearing of forests for agriculture.

All the carbon dioxide builds up in the EarthAll the carbon dioxide builds up in the Earth’’s s atmosphere, trapping heat. atmosphere, trapping heat.

Greenhouse effect:Greenhouse effect:

Natural process that stops all sunNatural process that stops all sun’’s heat from escaping s heat from escaping rapidly back to space.rapidly back to space.

This is leading to global warming.This is leading to global warming.

Global warming:Global warming:

Rise in EarthRise in Earth’’s average temperature. s average temperature.

Other effects of Other effects of PollutionPollution

Who here eats fish? Who here eats fish?

Why do some people not eat fish anymore?Why do some people not eat fish anymore?

High amounts of mercury.High amounts of mercury.

Bio MagnificationBio MagnificationIf a small fish has mercury in its system and gets eaten If a small fish has mercury in its system and gets eaten by a bigger fish… the bigger fish now has a higher by a bigger fish… the bigger fish now has a higher amount of mercury in its system.amount of mercury in its system.

The amount of mercury increases as the small fish gets The amount of mercury increases as the small fish gets consumed and moves up a food chain.consumed and moves up a food chain.

Ozone LayerOzone LayerPollution in the atmosphere affects a gas called ozone Pollution in the atmosphere affects a gas called ozone (O3).(O3).

Ozone layer absorbs ultraviolet radiation, and shields Ozone layer absorbs ultraviolet radiation, and shields organisms. organisms.

Ozone layer is thinning because of Ozone layer is thinning because of chlorofluorocarbons.chlorofluorocarbons.

Aerosol cans, refrigerator units. Aerosol cans, refrigerator units.

36.5 Conservation 36.5 Conservation BiologyBiology

Which biome has the most biodiversity?Which biome has the most biodiversity?

Tropical Rainforest!Tropical Rainforest!

What is happening to our tropical rainforests?What is happening to our tropical rainforests?

DeforestationDeforestation

Threats to BiodiversityThreats to Biodiversity11% of the 9,040 bird species are endangered.11% of the 9,040 bird species are endangered.

680 plant species of the 20,000 plant species in the US 680 plant species of the 20,000 plant species in the US are endangered.are endangered.

Biologist estimate that 20% of the freshwater fish in Biologist estimate that 20% of the freshwater fish in the world have either become extinct or threatened. the world have either become extinct or threatened.

Habitat DestructionHabitat DestructionThe human population is increasing so we need more The human population is increasing so we need more land for agriculture, roads etc. land for agriculture, roads etc.

Introduced SpeciesIntroduced SpeciesIntroduced species: Non-native speciesIntroduced species: Non-native species

House sparrows, starlings came over from Europe. House sparrows, starlings came over from Europe.

Compete with native birds for nesting spots.Compete with native birds for nesting spots.

Share resources. Share resources.

OverexploitationOverexploitationOverexploitation:Overexploitation:

Practice of harvesting or hunting to a degree that the Practice of harvesting or hunting to a degree that the number of remaining individuals may not be able to number of remaining individuals may not be able to sustain the population.sustain the population.

Ex. Rhino-Use horns for trade and medicine.Ex. Rhino-Use horns for trade and medicine.

Scallop- Overfished for food. Scallop- Overfished for food.

Conservation BiologyConservation BiologyHow to we maintain biodiversity and ecosystems?How to we maintain biodiversity and ecosystems?

Balance demands for resourcesBalance demands for resources

Establish areas than humans can not interfere with. Establish areas than humans can not interfere with. (buffer zones) (buffer zones)

Develop natural resources. Develop natural resources.

Wolves back in Wolves back in parkpark

https://www.youtube.com/watch?v=ysa5OBhXz-Q