Download Ecology seeks to explain the distribution and abundance of

Ecology seeks to explain the distribution and
abundance of organisms on earth
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Autecology (physiological ecology)
Population ecology
Community ecology
Landscape ecology
Ecosystems ecology
Ecology seeks to explain the distribution and
abundance of organisms on earth
•
•
•
•
•
Autecology (physiological ecology)
Population ecology
Community ecology
Landscape ecology
Ecosystems ecology
Ecology seeks to explain the distribution and
abundance of organisms on earth
•
•
•
•
•
Autecology (physiological ecology)
Population ecology
Community ecology
Landscape ecology
Ecosystems ecology
The scientific process
• Identification of patterns
• Development of explanations or
hypotheses for these patterns
• Development of predictions from the
hypotheses
• Testing of predictions with data
Identification of patterns
• Temperate edges tend to have more bird
species that forest interior
• Tropical edges tend to have fewer bird
species than forest interior
Development of explanations or
hypotheses for these patterns
Development of predictions from
the hypotheses
Testing of predictions with data
Issues with study
• Not many studies, particularly in tropical
regions
• Investigators used a variety of distance
classes and techniques to assess edge
responses
Ecology seeks to explain the distribution and
abundance of organisms on earth
•
•
•
•
•
Autecology (physiological ecology)
Population ecology
Community ecology
Landscape ecology
Ecosystems ecology
Levels of organization in ecology
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Individual
Population
Metapopulation
Species
Assemblage
Community
Ecosystem
• Geographic range (distribution)—
geographic area permanently occupied by
a plant or animal taxon.
• A geographic range is not equivalent to a
home range or a territory of an individual.
Ecological biogeography
• Organisms’ distributions are affected
by their interactions with both their
physical and biological environments
Physical environment and effects on
distributions—the example of temperature
regulation
• Endotherms vs. ectotherms or
homeotherms vs. poikilotherms
Implications of endothermy in birds
and mammals
• Ability to inhabit a wide range of
environments
• Higher food and oxygen demands
• Limits to lower body size
Other examples of physical
environment influencing distributions
• Loblolly pine
• Sugar maples
• Starlings and Crested Mynahs
Comparative data
European
Starling
Crested Mynah
Eggs laid
5.2
5.1
Eggs hatched
82%
58%
Young fledged
69%
38%
Cross-fostering experiment
Percentage hatching
Mynah eggs in
European Starling nest
90%
Starling eggs in Mynah
nest
62%
Heater experiment
Percentage hatching
Mynah eggs in heated
nest boxes
92%
Mynah eggs in unheated
nest boxes
64%
Biotic environment and effects on
distributions
Competition, predation,
mutualism and herbivory are
other biotic interactions that may
affect organisms’ distributions
and abundances
• Competition may at times control ranges,
as in the example of the doves on islands
off New Guinea, although this is difficult to
say definitively.
Predators do not generally limit
the geographic ranges of their
prey, except in the case of exotic
species
• Species with tight mutualistic relationships
with other species may be confined to a
specific geographic range because of the
relationship—for example Acacia plants
and their ant mutualists of the genus
Pseudomyrmex.
• Most parasite species can live on only one
host species, for example many lice live
on only one species of birds. Hence, the
geographic range of the parasite is strictly
controlled by that of the host.
Ways in which humans (a biotic factor)
influence the distribution and abundance of
disease parasites
• High human density necessary for
measles to survive
• Humans influence the density of host
organisms besides themselves--Whitetailed deer, bacteria, ticks and Lyme’s
disease
• Humans spread parasites from one
continent to another
• Humans change the landscape
Ways in which humans (a biotic factor)
influence the distribution and abundance of
disease parasites
• High human density necessary for
measles to survive
• Humans influence the density of host
organisms besides themselves--Whitetailed deer, bacteria, ticks and Lyme’s
disease
• Humans spread parasites from one
continent to another
• Humans change the landscape
Ways in which humans (a biotic factor)
influence the distribution and abundance of
disease parasites
• High human density necessary for
measles to survive
• Humans influence the density of host
organisms besides themselves--Whitetailed deer, bacteria, ticks and Lyme’s
disease
• Humans spread parasites from one
continent to another
• Humans change the landscape
• Before European contact, the indigenous
population of South America was between
4 and 10 million.
• 100 years after contact, the population
was approximately 100,000.
• In many cases both physical and biotic
environments of organisms will influence
their distributions
• Ex. Barnacles, Balanus balanoides and
Chthamalus stellatus, on the Scottish
coast
Biogeographers consider how physical and
biotic factors shape geographic ranges
within a historical perspective
• Coffee example
• New Zealand birds
Biogeographers consider these concepts
and data within a historical perspective
• Coffee example
• New Zealand birds