ECOLOGY (Ch. 50-53) 1

THE REVIEW!!!

Fig. 52-2Organismalecology

Populationecology

Communityecology

Ecosystemecology

Landscapeecology

Globalecology

Species dispersal and distributionWhy is species X absent

from an area?

Does dispersallimit its

distribution? Does behaviorlimit its

distribution?

Area inaccessibleor insufficient time

Yes

No

No

No

Yes

Yes

Habitat selection

Do biotic factors(other species)

limit itsdistribution?

Predation, parasitism,competition, disease

Do abiotic factorslimit its

distribution?

Chemicalfactors

Physicalfactors

WaterOxygenSalinitypHSoil nutrients, etc.

TemperatureLightSoil structureFireMoisture, etc.

Problems with Introduced Species

• Different factors may determine the distribution of a species on different scales– Refer to the biomes and biome characteristics

• Most species have small geographic ranges

9

Animal Behaviors

• Defensive, Mating, etc.

• Behavioral has both proximate and ultimate causes– Proximate: elicit a behavior– Ultimate: evolutionary significance

• Behavior results from both genes and environmental factors

•

Fig. 53-12

2,000

1,500

1,000

500

00 5 10 15

Number of generations

Po

pu

lati

on

siz

e (N

)

Exponentialgrowth

1.0N=dN

dt

1.0N=dN

dt

K = 1,500

Logistic growth1,500 – N

1,500

How populations are linked 23

Trophic levels

Food Chain

Food Web

Energy Pyramids

Producers, Consumers, Heterotrophs, Autotrophs (photo, chemo)

25

Ch. 54-Ecosystems

• All of the biotic and abiotic factors interacting.• NPP=GPP-R• Limiting Factors

A General Model of Chemical Cycling

Biological Magnification

• When toxins become more concentrated in successive trophic levels of a food web.

Ch. 55 Conservation Biology

• Endangered Species

• Introduced Species– Invasive species