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. Community

All 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.

Niche

The 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:

Commensalism

One species benefits and the other species is unaffected.

Example: epiphyte- grows on a host plant for support.