Ecology
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Transcript of Ecology
Ecology
Ecology
Study of the interactions between organisms and their environments.
Environmental levels of organization:
1. Biosphere
Broadest level of ecological organization.
The thin volume of Earth and atmosphere where life is found.
2. EcosystemSmaller unit of the biosphere. Includes the organisms and
non-living environment in a particular place.
Ex: A pond ecosystem- fish, frogs, algae, pH, temperature
3. CommunityAll the interacting organisms in
an area.Ex: Pond community- fish,
turtles, algae and bacteria
4. Population
The members of a single species.
Ex: Population of frogs in a pond.
5. Organism
Simplest level of organization.Ex: A frog
Where does an organism live?Habitat: Environmental area
where a species lives.
NicheThe role or interactions an
organism has in its environment. Includes: range of conditions
that the species can tolerate, the resources it uses, the methods it uses to obtain resources, the number of offspring.
Generalists
Species with broad niches; they can tolerate a wide range of conditions and use a variety of resources.
Specialists
Species that have narrow niches; they are very limited in the conditions and resources they can use.
Why does it live there?
Generally depends on several environmental factors:AbioticBiotic
Abiotic FactorsThe physical and chemical
characteristics of an environment.
Includes: soil, temperature, pH, salinity, oxygen concentration, sunlight, and precipitation, etc.
Varies by place and over time.
What is soil?
Soil: is a complex mixture of inorganic minerals, decaying organic matter, water, air, and living organisms
How is soil produced?
Produced by a process called weathering, which breaks down rocks via erosion and decomposition
Layers of Soil Topsoil: uppermost layer that
consists of twigs, leaves, insects, etc
Subsoil: consists of rock particles and minerals
Weather Rock: made of bits of rock broken (bedrock)
How Does Soil Differ?
Differs according to mineral content, pH, organic content, etc.
Differs according to location or biome that it is found in.
Biotic Factors
The living factors that affect an organism.
Includes the presence of organisms, and their interactions
Ex. Parasitism, disease, predation
Competition When two or more species use
the same limited resource. Results in reduction of species
population or elimination of one species
Example of resources: food, light, soil
Predation Important interaction that
controls population size.Results in adaptations of both
predator and prey.Think of examples:
CamouflageBody pattern or coloration,
allows species to blend in with surroundings
Mimicry: one species resembles another
Harmless resembles a harmful
Top: Harmless species
Bottom: Poisonous species
Mimicry: one species resembles another
Harmless resembles a harmful
Several harmful species resemble each other.
Various wasp species
SymbiosisA close, long-term relationship
between organisms of two species.
3 types: ParasitismMutualismcommensalism
Parasitism The host is harmed and the parasite
is benefitted. Parasites tend to be highly adapted
for the host they feed on. Ectoparasites feed outside the body. Endoparasite live inside the body.
Examples of parasitism Leeches, mosquitoes, tapeworms
MutualismBoth species benefit. Think of some examples:
CommensalismOne species benefits and the
other species is unaffected.
Example: epiphyte- grows on a host plant for support.