Download LE 50-2

Introducción al estudio de
Ecología
PowerPoint Lectures for
Biology, Seventh Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Ecología es el estudio científico de las
interacciones entre los organismos y su ambiente
• Estas interacciones determinan la distribución de
los organismos y su abundancia
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• La ecología tiene una larga historia como una
ciencia descriptiva
• Y es también una rigurosa ciencia experimental
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• Eventos que ocurren en tiempos ecológicos
afectan la vida a escalas de tiempo evolutivo
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Los Organismos y el Ambiente
• El ambiente de cualquier organismo incluye:
– Componentes Abióticos
– Componentes Bióticos
• Todos los organismos que son parte de un
ambiente constituyen su biota
• Los componentes ambientales afectan la
distribución y abundancia de los organismos
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-2
Kangaroos/km2
> 20
10–20
5–10
1–5
0.1–1
< 0.1
Limits of
distribution
Tasmania
• Los ecólogos usan sus observaciones y
experimentos para proponer explicaciones para la
distribución y abundancia de las especies
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• La ecología organísmica estudia cómo la
estructura de un organismo, su fisiología, y (en los
animales) su comportamiento, se ajustan a
cambios ambientales
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Ecología organísmica
• La ecología de poblaciones se enfoca en los
factores que afectan la cantidad de individuos de
una especie que viven en la misma área
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LE 50-3b
Ecología de Poblaciones
• La ecología de comunidades estudia el conjunto
de especies que interaccionan en una comunidad
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LE 50-3c
Ecología de comunidades
• La ecología de los ecosistemas hace énfasis en el
flujo de energía y los ciclos químicos entre los
componentes bióticos y abióticos
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Ecología de ecosistema
• La ecología del paisaje estudia los ordenamientos
de los ecosistemas en una región geográfica
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LE 50-3e
Ecología del paisaje
• La biosfera es el ecosistema global, la suma de
todos los ecosistemas del planeta
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Ecology and Environmental Issues
• Ecology provides the scientific understanding
underlying environmental issues
• Rachel Carson is credited with starting the modern
environmental movement
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• La mayoría de los ecólogos sigue el principio de
precaución respecto de los temas ambientales
• Este establece que los humanos debieran sentirse
afectados por cómo sus acciones afectan a su vez
al ambiente
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 50.2: Interactions between organisms and
the environment limit the distribution of species
• Ecologists have long recognized global and
regional patterns of distribution of organisms
within the biosphere
• Many naturalists began to identify broad patterns
of distribution by naming biogeographic realms
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-5
Palearctic
Nearctic
Tropic
of Cancer
(23.5°N)
Oriental
Ethiopian
Equator
Neotropical
(23.5°S)
Tropic of
Capricorn
Australian
• Biogeography is a good starting point for
understanding what limits geographic distribution
of species
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-6
Species absent
because
Yes Area inaccessible
or insufficient time
Dispersal
limits
distribution?
No
Behavior
limits
distribution?
Yes
No
Habitat selection
Biotic factors
(other species)
limit
distribution?
Yes Predation, parasitism,
Chemical
competition, disease factors
Water
Oxygen
Abiotic factors
Salinity
No
limit
pH
distribution?
Soil nutrients, etc.
Temperature
Physical Light
factors Soil structure
Fire
Moisture, etc.
Dispersal and Distribution
• Dispersal is movement of individuals away from
centers of high population density or from their
area of origin
• Dispersal contributes to global distribution of
organisms
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Natural Range Expansions
• Natural range expansions show the influence of
dispersal on distribution
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-7
New areas
occupied Year
1996
1989
1974
Species Transplants
• Species transplants include organisms that are
intentionally or accidentally relocated from their
original distribution
• Species transplants can disrupt the communities
or ecosystems to which they have been introduced
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Behavior and Habitat Selection
• Some organisms do not occupy all of their
potential range
• Species distribution may be limited by habitat
selection behavior
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Biotic Factors
• Biotic factors that affect the distribution of
organisms may include:
– Interactions with other species
– Predation
– Competition
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-8
100
Sea
urchin
Seaweed cover (%)
80
Both limpets
and urchins
removed
Only
urchins
removed
60
Limpet
40
Only limpets removed
Control (both
urchins and
limpets present)
20
0
August
1982
February
1983
August
1983
February
1984
Abiotic Factors
• Abiotic factors affecting distribution of organisms:
– Temperature
– Water
– Sunlight
– Wind
– Rocks and soil
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Temperature
• Environmental temperature is an important factor
in distribution of organisms because of its effects
on biological processes
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Water
• Water availability in habitats is another important
factor in species distribution
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Sunlight
• Light intensity and quality affects photosynthesis
• Light is also important to development and
behavior of organisms sensitive to photoperiod
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Wind
• Wind amplifies effects of temperature by
increasing heat loss from evaporation and
convection
• Wind can change morphology of plants
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Rocks and Soil
• Many characteristics of soil limit distribution of
plants and thus the animals that feed upon them:
– Physical structure
– pH
– Mineral composition
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Climate
• Four major abiotic components of climate:
temperature, water, sunlight, and wind
• Climate is the prevailing weather in an area
• Macroclimate consists of patterns on the global,
regional, and local level
• Microclimate consists of very fine patterns, such
as those encountered by the community of
organisms underneath a fallen log
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Global Climate Patterns
• Global climate patterns are determined largely by
solar energy and the planet’s movement in space
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Sunlight intensity plays a major part in determining
the Earth’s climate patterns
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-10a
North Pole
60°N
Low angle of incoming sunlight
30°N
Tropic of
Cancer
Sunlight directly overhead at equinoxes
0° (equator)
Tropic of
Capricorn
30°S
Low angle of incoming sunlight
60°S
South Pole
Atmosphere
• Seasonal variations of light and temperature
increase steadily toward the poles
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-10b
60°N
30°N
June solstice:
Northern Hemisphere
tilts toward sun;
summer begins in
Northern
Hemisphere; winter
begins in Southern
Hemisphere.
0° (equator)
March equinox: Equator faces sun
directly; neither pole tilts toward sun;
all regions on Earth experience 12
hours of daylight and 12 hours of
darkness.
30°S
Constant tilt
of 23.5°
September equinox: Equator faces
sun directly; neither pole tilts
toward sun; all regions on Earth
experience 12 hours of daylight and
12 hours of darkness.
December solstice:
Northern Hemisphere tilts
away from sun; winter
begins in Northern
Hemisphere; summer
begins in Southern
Hemisphere.
• Global air circulation and wind patterns play major
roles in determining climate patterns
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-10c
60°N
30°N
Descending
dry air
absorbs
moisture
0° (equator)
30°S
60°S
.5°
30° 23
Arid
zone
Ascending
moist air
releases
moisture
0°
Tropics
Descending
dry air
absorbs
moisture
23.5° 30
°
Arid
zone
LE 50-10d
Westerlies
Arctic
Circle
60°N
30°N
Northeast trades
Doldrums
Southeast trades
0°
(equator)
30°S
Westerlies
60°S
Antarctic
Circle
Regional, Local, and Seasonal Effects on Climate
• Various features of the landscape contribute to
local variations in climate
• Seasonal variation also influences climate
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Bodies of Water
• Oceans and their currents and large lakes
moderate the climate of nearby terrestrial
environments
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Mountains
• Mountains have a significant effect on
– The amount of sunlight reaching an area
– Local temperature
– Rainfall
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-12
Wind
direction
East
Pacific
Ocean
Coast
Range
Sierra
Nevada
Seasonality
• The angle of the sun leads to many seasonal
changes in local environments
• Lakes are sensitive to seasonal temperature
change and experience seasonal turnover
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
0
4
8
Spring
Winter
O2 (mg/L)
12
8
16
2°
4°
4°
4°
4°C
24
O2 concentration
0°
4°
4°
Lake depth (m)
Lake depth (m)
LE 50-13
O2 (mg/L)
0
4
8
12
8
16
24
4°
4°
4°
4°C
High (>8 mg/L)
Medium (4–8 mg/L)
O2 (mg/L)
0
4
8
12
8
4°
22°
20°
18°
8°
6°
5°
4°C
4°
4°
4°
4°C
16
24
4°
Autumn
Thermocline
Summer
Lake depth (m)
Lake depth (m)
Low (<4 mg/L)
O2 (mg/L)
0
8
16
24
4
8
12
Microclimate
• Microclimate is determined by fine-scale
differences in abiotic factors
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Long-Term Climate Change
• One way to predict future global climate change is
to study previous changes
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-14
Current
range
Predicted
range
Overlap
4.5°C warming over
next century
6.5°C warming over
next century
Concept 50.3: Abiotic and biotic factors influence
the structure and dynamics of aquatic biomes
• Varying combinations of biotic and abiotic factors
determine the nature of biomes
• Biomes are the major ecological associations that
occupy broad geographic regions of land or water
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Aquatic biomes account for the largest part of the
biosphere in terms of area
• They can contain fresh water or salt water
• Oceans cover about 75% of Earth’s surface and
have an enormous impact on the biosphere
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-15
30°N
Tropic of
Cancer
Equator
Tropic of
Capricorn
Continental
shelf
30°S
Key
Lakes
Rivers
Estuaries
Coral
reefs
Oceanic
pelagic zone
Intertidal
zone
Abyssal zone
(below oceanic
pelagic zone)
• Many aquatic biomes are stratified into zones or
layers defined by light penetration, temperature,
and depth
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-16a
Littoral
zone
Limnetic
zone
Photic
zone
Benthic
zone
Zonation in a lake
Pelagic
zone
Aphotic
zone
LE 50-16b
Intertidal zone
Neritic zone
0
Oceanic zone
Photic zone
200 m
Continental
shelf
Pelagic
zone
Benthic
zone
2,500–6,000 m
Abyssal zone
(deepest regions of ocean floor)
Marine zonation
Aphotic
zone
• Major aquatic biomes:
– Lakes
– Wetlands
– Streams and rivers
– Estuaries
– Intertidal zones
– Oceanic pelagic biome
– Coral reefs
– Marine benthic zone
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Video: Clownfish and Anemone
Video: Coral Reef
Video: Flapping Geese
Video: Hydrothermal Vent
Video: Shark Eating a Seal
Video: Tubeworms
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Concept 50.4: Climate largely determines the
distribution and structure of terrestrial biomes
• Climate is very important in determining why
terrestrial biomes are found in certain areas
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Climate and Terrestrial Biomes
• Climate has a great impact on the distribution of
organisms, as seen on a climograph
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
LE 50-18
Desert
Temperate grassland
Tropical forest
Annual mean temperature (°C)
30
Temperate
broadleaf
forest
15
Coniferous
forest
0
Arctic and
alpine
tundra
–15
100
200
300
Annual mean precipitation (cm)
400
LE 50-19
30°N
Tropic of
Cancer
Equator
Tropic of
Capricorn
30°S
Key
Tropical forest
Savanna
Desert
Chaparral
Temperate grassland
Temperate broadleaf forest
Coniferous forest
Tundra
High mountains
Polar ice
General Features of Terrestrial Biomes
• Terrestrial biomes are often named for major
physical or climatic factors and for vegetation
• Stratification is a key feature of terrestrial biomes
• Terrestrial biomes usually grade into each other,
without sharp boundaries
• The area of intergradation, called an ecotone, may
be wide or narrow
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Major terrestrial biomes:
– Tropical forest
– Desert
– Savanna
– Chaparral
– Temperate grassland
– Coniferous forest
– Temperate broadleaf forest
– Tundra
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Video: Swans Taking Flight
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings