Download Ch 52 Ecology

Introduction to Ecology
Chapter 52
http://www.geog.uni-heidelberg.de/~ttavk/weltkarten/globen/1997-1998-biosphere-Nasa.jpg
Ecology
• interactions
of organisms
with their
environment
Organisms & the Environment
• Abiotic Factors: non-living
• temperature, humidity,
precipitation, water,
climate, wind, sunlight, soil
composition, etc…
• Biotic Factors: living
• predation, herbivory,
presence or absence of
pollinators, food
resources, parasites,
pathogens, competing
organisms
Levels of Organization
 Biosphere
 Biome
 Ecosystem
 Community
 Population
 Organism
 BBECPO
BIOSPHERE
 portion of planet in which all life exists
(includes land, water, atmosphere)
Extends from:
8 km above the
Earth’s surface to 11
km below the ocean’s
surface
BIOME
• the world’s ecosystems classified according
to dominant vegetation & rainfall
Biomes
Aquatic
• Marine
• Intertidal zones
• Oceanic Pelagic
• Coral reefs
• Marine benthic
zone
• Freshwater
• Lakes
• Wetlands
• Streams and rivers
• Estuaries
Terrestrial
Tropical
Desert
Savanna
Chaparral
Grassland
Coniferous forest
(taiga)
• Broadleaf forest
(deciduous)
• Tundra (arctic)
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ECOSYSTEM
 All the organisms in a community plus abiotic
factors
 ecosystems are transformers of energy
& processors of matter
 Ecosystems are self-sustaining
 what is needed?
 capture energy
 transfer energy
 cycle nutrients
COMMUNITY
• All the organisms that inhabit an area
POPULATION
 individuals of the same species living in an
area.

capable of interbreeding and producing fertile offspring)
Biogeographic Realms
Organism’s Habitat
• habitat: place where an
organism lives
• dispersal: movement of
individuals from areas of
high population density
(or their area of origin)
• disruption of existing
communities and
ecosystems usually occurs
Organism’s Tolerance
• tolerance: range of
conditions an
organism can
withstand
• acclimation:
changing in response
to environmental
factors
Climate
• Macroclimate: global and regional
• Microclimate: community
• affected by:
•
•
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•
sunlight – warming – longitudinal variations
temperature
water
wind
• temperature & moisture: main factors
that limit plant & animal species in
geographic regions
Global Climate Patterns
Responses to Change in Biotic &
Abiotic Environment
• Migration
• Hibernation / Dormancy
• Conformers: change with
the environments
• Regulators: maintain
homeostasis regardless
of external environment
Organism’s Niche
• Niche: organism’s role in the environment
• includes ALL biotic & abiotic factors an organism
needs or uses
• fundamental niche: range or resources the organism
can potentially use
• realized niche: resources the organism actually uses
• if niches overlap  competition for resources
• Natural Selection
No two species can occupy
the same niche!
Competitive exclusion principle