What is Ecology?What is Ecology?1. “The scientific study 1. “The scientific study of the interactions of the interactions between organisms and between organisms and their environments is their environments is called ecology.”called ecology.”

2. “The trouble with 2. “The trouble with ecology is that you never ecology is that you never know where to start know where to start because everything because everything affects everything else.”affects everything else.”

3. “Ecologists often face extraordinary 3. “Ecologists often face extraordinary challenges in their research because of challenges in their research because of the complexity of their questions, the the complexity of their questions, the diversity of their subjects, and the diversity of their subjects, and the large expanses of time and space over large expanses of time and space over which studies must often be conducted. which studies must often be conducted. Ecology is also challenging because of Ecology is also challenging because of its multidisciplinary nature; ecological its multidisciplinary nature; ecological questions form a continuum with those questions form a continuum with those from other areas of biology, including from other areas of biology, including genetics, evolution, physiology, and genetics, evolution, physiology, and behavior, as well as those from other behavior, as well as those from other sciences, such as chemistry, physics, sciences, such as chemistry, physics, geology, and meteorology.”geology, and meteorology.”

4. “Ecology concerns itself 4. “Ecology concerns itself with the interrelationships with the interrelationships of living organisms, plant or of living organisms, plant or animal, and their animal, and their environments; these are environments; these are studied with a view to studied with a view to discovering the principles discovering the principles which govern the which govern the relationships.”relationships.”

What is Ecology?What is Ecology?

5. “In other words, 5. “In other words, understanding ecology understanding ecology requires understanding requires understanding everything else there is to everything else there is to know about biology, and then know about biology, and then some. It’s probably the some. It’s probably the easiest part of Biology to easiest part of Biology to recognize and the hardest recognize and the hardest part to really understand.”part to really understand.”

Assignment #1:Assignment #1: Give your own definition of Give your own definition of EcologyEcology

Ecosystems:Ecosystems: Food chains, Food webs Food chains, Food webs and Food pyramidsand Food pyramids

TAKS Objective 3TAKS Objective 3

TEKS 12 ETEKS 12 E

Gotta get cha eat on!Gotta get cha eat on!

Many of the relationships between Many of the relationships between living organisms in an living organisms in an ecosystem have to do with food.ecosystem have to do with food.

Energy is passed from one to Energy is passed from one to another!another!

Scientists use graphic Scientists use graphic representations to show food representations to show food

relationships and energy relationships and energy transfer in an ecosystemtransfer in an ecosystem

3 Graphic Representations:3 Graphic Representations:

1)1) Food ChainsFood Chains

2)2) Food WebsFood Webs

3)3) Pyramids – three typesPyramids – three types

a.a. Energy Energy

b.b. NumbersNumbers

c.c. BiomassBiomass

Assignment #2:Assignment #2:Draw your own food chainDraw your own food chain

Remember:Remember:

Arrows show the flow of Arrows show the flow of energyenergy

Arrows point to the thing that Arrows point to the thing that

eatseats

Autotrophs make their own Autotrophs make their own foodfoodHeterotrophs eat autotrophsHeterotrophs eat autotrophs

Autotrophs = ProducersAutotrophs = Producers

Herbivores Herbivores = Primary Consumers= Primary Consumers

CarnivoresCarnivores = Secondary, tertiary, = Secondary, tertiary, etc. consumersetc. consumers

Decomposers are always the Decomposers are always the final consumersfinal consumers

Assignment #3:Assignment #3:Draw another food chainDraw another food chain

Label theLabel theProducer (the autotroph)Producer (the autotroph)Primary ConsumerPrimary ConsumerSecondary ConsumerSecondary ConsumerTertiary ConsumerTertiary Consumer

Decomposer (final consumer)Decomposer (final consumer)

Food chainsFood chains show the flow of show the flow of energy through an ecosystemenergy through an ecosystem

Food Chain:Food Chain: an example an example

Grass→Grasshopper→Toad→Grass→Grasshopper→Toad→Snake→Hawk→Bacterial Snake→Hawk→Bacterial decaydecay

Arrows show the flow of energyArrows show the flow of energyArrows point to the thing that Arrows point to the thing that

eats eats

Food ChainFood Chain

Food WebsFood Webs: many : many interconnected food chains; link interconnected food chains; link

of all food chains in an of all food chains in an ecosystemecosystem

Assignment #4:Assignment #4: Why is a Why is a food web more realistic food web more realistic

than a food chain?than a food chain?

Types of SymbiosisTypes of Symbiosis

MutualismMutualism

CommensalismCommensalism

ParasitismParasitism

Trophic LevelsTrophic LevelsEach step in a food chain or food Each step in a food chain or food

web is called a web is called a trophictrophic levellevel..11stst Trophic Level Trophic Level – producers – producers 22nd+nd+ Trophic Level Trophic Level – consumers – consumers

(primary, secondary, tertiary, etc.)(primary, secondary, tertiary, etc.)Each consumer depends on the Each consumer depends on the

trophic level below it for energy; trophic level below it for energy; only 10%only 10% of energy goes on to of energy goes on to the next trophic level!the next trophic level!

Pyramids show changes in either Pyramids show changes in either energyenergy or or numbersnumbers or or mass mass

1.1. Energy pyramids:Energy pyramids: change in energy change in energy from trophic level to the next; from trophic level to the next; only only 10% passes up to next level.10% passes up to next level.

2.2. Numbers pyramids:Numbers pyramids: change in change in number of individuals at each trophic number of individuals at each trophic level.level.

3.3. Biomass pyramids:Biomass pyramids: change in dry change in dry weight (biomass) from trophic level weight (biomass) from trophic level to the next.to the next.

Top Level Consumer

Primary Consumer

Producer

Pyramid of numbers

Top Level Consumer

Primary Consumer

Producer

Last Assignment #5: Draw your own ecological pyramid

QuestionQuestionAnimalAnimal Length of Length of

digestive systemdigestive systemDiet categoryDiet category Animal weightAnimal weight

KoalaKoala 305 cm305 cm herbivoreherbivore 10 kg10 kg

DogDog 135 cm135 cm carnivorecarnivore 11 kg11 kg

RabbitRabbit 272 cm272 cm herbivoreherbivore 9 kg9 kg

BobcatBobcat 145 cm145 cm carnivorecarnivore 12 kg12 kg

1.The table shows data about several herbivores and carnivores. 1.The table shows data about several herbivores and carnivores. Based on the data, what conclusion can you draw from the data?Based on the data, what conclusion can you draw from the data?

a. There is no correlation between diet and length of digestive a. There is no correlation between diet and length of digestive system.system.

b. Herbivores have longer digestive systems than carnivores.b. Herbivores have longer digestive systems than carnivores. c. Carnivores have longer digestive systems than herbivores.c. Carnivores have longer digestive systems than herbivores. d. The length of the digestive system is related to the weight of an d. The length of the digestive system is related to the weight of an

animal.animal.