Ecosystems & Ecosystems & Biological Biological

CommunitiesCommunities

Chapter 16 & 17Chapter 16 & 17

Interactions Interactions pg 340pg 340 EcologyEcology is the study of is the study of

the interactions of living the interactions of living organisms with one organisms with one another.another.

What does the word really What does the word really mean?mean?

house or place where house or place where one livesone lives

A community is A community is made up of made up of manymany different species different species that live that live together.together.

The place where an organism lives is its habitat.

Interaction in an EcosystemInteraction in an Ecosystem

Define biotic factors: Define biotic factors: organisms in a habitatorganisms in a habitat

Rabbit in a burrowFish in water

Squirrel in a tree

Interaction in an EcosystemInteraction in an Ecosystem

Define abiotic Define abiotic factors: factors: physical physical aspects of a aspects of a habitathabitat Sand

Soil

Water

Energy Flow in EcosystemsEnergy Flow in Ecosystems

Most life on earth Most life on earth depends on depends on photosyntheticphotosynthetic organisms which organisms which capture some of the capture some of the sun’s sun’s lightlight energy and energy and store it as store it as chemicalchemical energy in organic energy in organic molecules.molecules.

What is the equation for What is the equation for

photosynthesis?photosynthesis?

6 CO6 CO22 + 6 H + 6 H22O + light O + light C C66HH1212OO6 6 + 6 O + 6 O22

Organisms that are the first to capture Organisms that are the first to capture energy are the energy are the producersproducers which which include include plantsplants, some kinds of , some kinds of bacteriabacteria, and , and algaealgae..

ConsumersConsumers are those organisms that are those organisms that consume plants or other organisms to consume plants or other organisms to obtain the obtain the energyenergy to build their to build their molecules. molecules.

Trophic LevelsTrophic Levels

Food Chains Food Chains

What occupies the first or lowest trophic level of any What occupies the first or lowest trophic level of any ecosystem? ecosystem?

ProducersProducers

What occupies the 2What occupies the 2ndnd trophic level? trophic level? Herbivores (primary consumers)Herbivores (primary consumers)

What occupies the 3What occupies the 3rdrd trophic level? trophic level?Secondary consumersSecondary consumers

What is the difference between a What is the difference between a carnivore and an omnivore?carnivore and an omnivore?

Carnivores eat meat only, Omnivores Carnivores eat meat only, Omnivores eat meat and plantseat meat and plants

Many ecosystems contain a 4Many ecosystems contain a 4thth trophic trophic level composed of level composed of carnivorescarnivores that that consume other consume other carnivorescarnivores..

Do ecosystems usually have more Do ecosystems usually have more than 4 trophic levels?than 4 trophic levels?

RarelyRarely

What role do bacteria and fungi play What role do bacteria and fungi play in an ecosystem?in an ecosystem?

Decomposers (break down dead Decomposers (break down dead plant and animal matter)plant and animal matter)

Loss of Energy in Food ChainLoss of Energy in Food ChainDuring every transfer of energy within an During every transfer of energy within an

ecosystem, energy is lost as ecosystem, energy is lost as heat.heat.

The loss of useful energy The loss of useful energy limitslimits the number of the number of trophic levelstrophic levels an ecosystem can support. At an ecosystem can support. At each trophic level, the energy stored by the each trophic level, the energy stored by the organisms in a level is about organisms in a level is about 1/101/10 of that of that stored by the organisms in the level stored by the organisms in the level belowbelow..

Ecologists often illustrate that flow of energy Ecologists often illustrate that flow of energy through ecosystems with an through ecosystems with an energy pyramidenergy pyramid. .

Energy Pyramid: a diagram in which each trophic level is represented by a block and the blocks are stacked on top of one another.

How many trophic levels are in Figure 9?

Why is the top trophic level the smallest?

4

Least amount of energy

PracticePractice

If the first trophic level contained 10,000 If the first trophic level contained 10,000 kcal of energy, how much energy would kcal of energy, how much energy would the 2the 2ndnd level have? level have?

33rdrd? ?

44thth??

1,000 kcal100 kcal

10 kcal

Cycling of Materials in Cycling of Materials in EcosystemsEcosystems

All materials that cycle through living All materials that cycle through living organisms are important in organisms are important in maintaining the health of ecosystems, maintaining the health of ecosystems, but 4 substances are particularly but 4 substances are particularly important: important: water, carbon, nitrogen water, carbon, nitrogen and phosphorus.and phosphorus.

CyclesCycles

The paths of water, carbon, nitrogen The paths of water, carbon, nitrogen and phosphorous pass from the and phosphorous pass from the nonlivingnonliving environment to environment to livingliving organisms, such as trees and then organisms, such as trees and then back to the nonliving environment.back to the nonliving environment.

The Water CycleThe Water Cycle

WaterWater has the greatest influence on the has the greatest influence on the ecosystem’s inhabitants.ecosystem’s inhabitants.

Water vapor in the Water vapor in the atmosphereatmosphere condenses and falls to the Earth’s condenses and falls to the Earth’s surface as rain or snow. The water surface as rain or snow. The water that seeps into the soil becomes part that seeps into the soil becomes part of the of the ground water.ground water.

Water CycleWater Cycle

Water is taken up by the roots Water is taken up by the roots

of plants and then moves into the of plants and then moves into the atmosphere by evaporating from the leaves atmosphere by evaporating from the leaves through through transpirationtranspiration..

Water CycleWater Cycle

The Carbon CycleThe Carbon Cycle

Carbon dioxide in the air or dissolved Carbon dioxide in the air or dissolved in water is used by in water is used by photosynthesizing plants, algae and photosynthesizing plants, algae and bacteria as a raw material to build bacteria as a raw material to build organic molecules. Carbon atoms organic molecules. Carbon atoms may return to the pool of carbon may return to the pool of carbon dioxide in the air and water in 3 dioxide in the air and water in 3 ways.ways.

The Carbon CycleThe Carbon Cycle

1. 1. RespirationRespiration- all - all organisms use organisms use oxygen to oxidize oxygen to oxidize organic molecules organic molecules producing carbon producing carbon dioxide.dioxide.

The Carbon CycleThe Carbon Cycle

2. 2. CombustionCombustion- The - The burning of wood burning of wood returns carbon to returns carbon to the atmosphere, as the atmosphere, as well as coal, oil, well as coal, oil, and natural gas. and natural gas. The carbon is The carbon is released when the released when the fossil fuel is burned. fossil fuel is burned.

Smoke and pollution from Borneo fires, 1997.

The Carbon CycleThe Carbon Cycle

3. 3. ErosionErosion-As limestone is exposed -As limestone is exposed and erodes, the carbon becomes and erodes, the carbon becomes available to other organisms.available to other organisms.

Also includes decompositionAlso includes decomposition

The Carbon CycleThe Carbon Cycle

The Phosphorus and Nitrogen The Phosphorus and Nitrogen CyclesCycles

Organisms need Organisms need nitrogennitrogen and and phosphorusphosphorus to build to build proteins and nucleic proteins and nucleic acids. Phosphorus is an acids. Phosphorus is an essential part of both essential part of both ATPATP and and DNADNA..

Phosphorus and Nitrogen CyclesPhosphorus and Nitrogen Cycles

Phosphate is absorbed by Phosphate is absorbed by the roots of plants and is the roots of plants and is eaten by animals.eaten by animals.

The atmosphere is 79% The atmosphere is 79% nitrogen gas, N2 but it is nitrogen gas, N2 but it is in an unusable form.in an unusable form.

Phosphorus and Nitrogen CyclesPhosphorus and Nitrogen Cycles

Some Some bacteriabacteria can break the can break the bond between the nitrogen bond between the nitrogen molecules to form ammonia molecules to form ammonia (NH(NH33). This is called ). This is called nitrogennitrogen fixationfixation. These bacteria live . These bacteria live in the soil and are also found in the soil and are also found in the nodules of roots of in the nodules of roots of beans, alder trees and a few beans, alder trees and a few other kinds of plants.other kinds of plants.

The Phosphorus The Phosphorus

4 stages of the Nitrogen Cycle:4 stages of the Nitrogen Cycle:

1. 1. AssimilationAssimilation- absorption and - absorption and incorporation of nitrogen into incorporation of nitrogen into plant and animal compoundsplant and animal compounds

2. 2. AmmonificationAmmonification- production of - production of ammonia by bacteria during the ammonia by bacteria during the decay of nitrogen- containing decay of nitrogen- containing urea (found in urine).urea (found in urine).

4 stages of the Nitrogen Cycle:4 stages of the Nitrogen Cycle:

3. 3. NitrificationNitrification- production of - production of nitrate from ammonianitrate from ammonia

4. 4. DenitrificationDenitrification- the conversion - the conversion of nitrate to nitrogen gas.of nitrate to nitrogen gas.

The Nitrogen Cycle

Nitrogen CycleNitrogen Cycle

Plant growth is limited by the availability of Plant growth is limited by the availability of nitrate and ammonia in the soil. Most nitrate and ammonia in the soil. Most farmers add nitrates to the soil thatfarmers add nitrates to the soil that

has been made in a factory rather than has been made in a factory rather than by nitrogen fixation. Genetic engineers by nitrogen fixation. Genetic engineers are trying to put the genes of the nitrogen-are trying to put the genes of the nitrogen-fixing fixing bacteriabacteria into plants. This would into plants. This would eliminate the need for nitrogen-supplying eliminate the need for nitrogen-supplying fertilizers. fertilizers.

Biological Communities Biological Communities

What is predation? What is predation?

The act of one organism killing another organism The act of one organism killing another organism for foodfor food

List 2 examples of predation.List 2 examples of predation.

11. bear and a fish. bear and a fish

2.2. lions and hippo lions and hippo

Symbiotic Species Symbiotic Species pg. 364pg. 364

Define:Define:

symbiosis: symbiosis: two or more species live two or more species live together in a close, long-term associationtogether in a close, long-term association

Symbiotic relationships can be Symbiotic relationships can be beneficialbeneficial to to both organisms or benefit one and leave both organisms or benefit one and leave the other the other harmedharmed or or unaffectedunaffected..

ParasitismParasitism

Parasitism is when one organism Parasitism is when one organism feedsfeeds onon and usually lives and usually lives onon or or inin another another organism. Parasites do not usually kill organism. Parasites do not usually kill their “host”.their “host”.

Example- fleas/ticks on dogsExample- fleas/ticks on dogs

MutualismMutualismMutualism is when both organisms Mutualism is when both organisms benefitbenefit. .

Examples: plover and Rhino Examples: plover and Rhino

CommensalismCommensalism

Commensalism is when oneCommensalism is when one

organism organism benefitsbenefits and the and the

other is neither other is neither harmedharmed or or

helpedhelped. .

Examples: clown fish and sea anemoneExamples: clown fish and sea anemone

Define:Define: competition: competition: two species use the same resource; two species use the same resource;

they participate in a biological interactionthey participate in a biological interaction

What resources might species compete for?What resources might species compete for?Water, food, nesting site, living space, light, Water, food, nesting site, living space, light,

mineral nutrientsmineral nutrients

Do most interactions involve fighting? Do most interactions involve fighting? nono

Define:Define: niche: niche: functional role of a particular functional role of a particular

species in an ecosystemspecies in an ecosystem

In what ways can a niche be described?In what ways can a niche be described?

How an organism lives OR the “job” it How an organism lives OR the “job” it performs within the ecosystemperforms within the ecosystem

Climate’s Effect on Where Climate’s Effect on Where Species LiveSpecies Live

A. The 2 most important element of A. The 2 most important element of climate are climate are temperaturetemperature and and moisturemoisture..

B. A major biological community that B. A major biological community that occurs over a large area of land is occurs over a large area of land is called a called a biomebiome..

7 Most Widely Recognized Land 7 Most Widely Recognized Land Biomes Are:Biomes Are:

1.1. Tropical Rainforest Tropical Rainforest

2.2. Savanna Savanna

3.3. Taiga Taiga

4.4. Tundra Tundra

5.5. Desert Desert

6.6. Temperate Grassland Temperate Grassland

7.7. Temperate Forest Temperate Forest

1.1. DeciduousDeciduous

2.2. EvergreenEvergreen

Many factors such as Many factors such as soilsoil typetype and and windwind play an important role in determining play an important role in determining where biomes occur. where biomes occur.

Aransas National Wildlife Refuge

Austwell, TX

Tropical RainforestTropical Rainforest

Dominica, West Indies

• Average 180 in. rainfall annually

• More species than other biomes

• ≥ half of terrestrial species

• Infertile soil (nutrients stored in plants

SavannaSavanna

Africa

• Dry grassland with prolonged dry season

• 35-60 in. rainfall

• Widely spaced trees

• Supports huge herds of grazers

TaigaTaiga

• Cold, wet climate with long winters

• Coniferous trees

• Largest biome

• Home of elk, moose, deer, wolves, bears, lynxes, wolverines

TundraTundra

Found between taiga Found between taiga and permanent ice and permanent ice around North polearound North pole

Covers 1/5 of land Covers 1/5 of land surfacesurface

< 25 in. rainfall< 25 in. rainfall

Permafrost- ground Permafrost- ground frozen within 3 ft. of frozen within 3 ft. of surfacesurface

DesertDesert

Langtry, TX near

Rio Grande River

• < 10 in. rainfall (varies greatly in specific locations)

• Sparse vegetation

• < 5% of North America

• Usually in interior of continent

Temperate GrasslandTemperate Grassland

• Moderate climate halfway between poles and equator

• Deep, fertile soils

• Maintained by herds of migratory grazers or fire

Cara and Rosie

Temperate Deciduous Forest Temperate Deciduous Forest Trees shed leaves in Trees shed leaves in fall fall

Warm summers, cold Warm summers, cold winterswinters

Rainfall = 30-100 in.Rainfall = 30-100 in.

Eastern U.S.Eastern U.S.

Deer, bears, beaver, Deer, bears, beaver, raccoon,raccoon,

Hardwood treesHardwood trees

Temperate Evergreen Forest Temperate Evergreen Forest Drier weather than Drier weather than deciduous, acidic soildeciduous, acidic soil

SE & W U.S.SE & W U.S.

Pine needles have Pine needles have resin to prevent water resin to prevent water lossloss

Seeds protected in pine Seeds protected in pine conecone

Ca. Redwood- tallest Ca. Redwood- tallest tree in world (up to 378 tree in world (up to 378 ft) and lives 2,000 yearsft) and lives 2,000 years

Aquatic CommunitiesAquatic Communities

Freshwater Communities- include Freshwater Communities- include lakes, lakes, ponds, streams, and riversponds, streams, and rivers..

3 zones that ponds and lakes have include:3 zones that ponds and lakes have include:1. Littoral- 1. Littoral- shallow end near the shoreshallow end near the shore2. Limnetic- 2. Limnetic- farther from shore but close farther from shore but close to surfaceto surface3. Profundal- 3. Profundal- deep water zone that is deep water zone that is below where light penetratesbelow where light penetrates

Figure 12, page 376Figure 12, page 376

WetlandsWetlands

Wetlands include Wetlands include swamps, marshesswamps, marshes, , and and bogsbogs..

Wetlands are Wetlands are dynamicdynamic communitiescommunities that support a diverse array of that support a diverse array of invertebrates, birds,invertebrates, birds, and other and other animalsanimals..

Marine CommunitiesMarine CommunitiesNearly Nearly ¾ (75%)¾ (75%) of the Earth’s surface is of the Earth’s surface is

covered by ocean.covered by ocean.

3 types of Marine communities:3 types of Marine communities:1. 1. Shallow ocean watersShallow ocean waters

What is the intertidal zone? What is the intertidal zone? Seashore between high and low Seashore between high and low tides; home of many invertebratestides; home of many invertebrates

2. 2. Surface of the open seasSurface of the open seas What is plankton? What is plankton? Bacteria, algae, Bacteria, algae,

fish larvae, small invertebratesfish larvae, small invertebrates

3. 3. Ocean Depths-Ocean Depths- deepest water of deepest water of the seathe sea