Chapter 50

Introduction to Ecology

Ecology studies the interactions between organisms and their environment. These interactions determine…

Distribution Abundance

Where do they live? How many are there?

250

200

150

100

50

0 m

Fin whale: Balaenoptera physalus

Distribution during Feb-Mar 2000-2001 from visual surveys

The distribution and abundance of organisms is determined by the interactions between organisms and their environment

Abiotic Biotic(nonliving components) (living components)

Relative importance of each component

End

StartEnd of spring

Summer

Start of fall

Dainet

Balaenoptera physalus Gulf of California population

BBCt

B. Tershy

500 species of cichliids from Lake Malawi in the last 1 million years

T. D. Kocher

First, trophic morphology; subsequently, sexual selection

Interactions between organisms and their environment that occur over a long enough period of time promote evolutionary change.

Nature 2005

Apparently, sexual selection

Hawaiian crickets, one of the highest rates of speciation

Organismalecology

coping

Populationecology

limiting factors

Community ecologyinterspecific interactions and diversity

Ecosystem ecologyenergy flow and chemical cycling

Landscape ecologyeffects on interactions at lower levels

Biosphere ecologyglobal effects

DISPERSALAccidental or deliberate

introduction

Fig. 50.8

BEHAVIOR/HABITAT SELECTIONAvoidance of certain areas

C. Roessler

BIOTIC FACTORSPredation, competition, parasitism, disease, pollination

Fig. 50.9

Effect on biological processes.Most organisms unable to regulate body temperature.

Aquatic: water balance.Terrestrial: desiccation.

Provides energy to photosynthetic organisms.Photoperiod: cuing of daily and seasonal cycles.

ABIOTIC FACTORS

TEMPERATURE, WATER, sunlight, wind Climate

Increases heat and water loss.Affects plant morphology.

Salinity, pH, rocks, soil, oxygen, density

Solar radiation and latitude

Fig. 50.11

Seasonal variations

Fig. 50.12

Seasonal effects on climate in the ocean

Upwelling index

Sea surface temperature

Productivity

Chlorophyll

Blue whale sightings

Monterey Bay

Krill backscatter

Data from D. Croll

Local effects on climate

Fig. 50.14

Aquatic Biomes

Largest component. Vertical stratification: light, temperature, salinity, density.Oceans (3% salt): rainfall, climate, wind. Give O2 and take CO2.Freshwater (< 1% salt): linked to soil and biota of terrestrial biomes.

Fig. 50.17

Ocean zonation

Fig. 50.22

Terrestrial Biomes

Fig. 50.24