Transcript • Biodiversity refers to the number and variety of species on Earth

Ecology and Biodiversity
Ecology

Ecology is the study of relationships between
all organisms and their environment.
Biosphere
The largest environment we focus on at one
time is the biosphere.
 The biosphere consists of the thin layer of the
earth’s surface where all organisms live.
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Biomes
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The biosphere can be divided into various
biomes which are the world's major
communities, classified according to the
predominant vegetation and characterized by
adaptations of organisms to that particular
environment.
Biomes

Each biome supports certain varieties of
organisms that are adapted to that
environment such that they are getting their
needs met and are successfully reproducing
offspring.
Examples of Biomes

Terrestrial Biomes (Land Biomes)
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Forests – Coniferous, Deciduous, Rain
Grasslands
Desert
Taiga
Tundra
Aquatic Biomes (Water Biomes)
◦ Freshwater Lakes, Ponds or Rivers
◦ Saltwater Oceans
◦ Brackish Water Wetlands
Levels of Organization
Ecosystem – a self-sustaining collection
of organisms and their environment.
 Community – all organisms that live in
a particular place
 Population – all members of a
particular species that live in a
particular place.
 Organism – one member of a
particular species that lives in a
particular place.
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Habitat vs. Niche

A habitat is the place in which an organism
lives (this can be big like the desert or small
like your backyard)
◦ for example – a frog lives near a pond-like habitat.
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A niche is the job or function of an organism
within its ecosystem
◦ for example – the frog eats insects and is eaten by
small animals and birds.
Components of an Ecosystem

Nonliving components of an ecosystem are
called abiotic factors.
◦ Examples: sunlight, rocks, slope of the land,
temperature

Living components of an ecosystem are called
biotic factors.
◦ Examples: all living organisms – plants, animals,
protists, bacteria, etc.
Describing Biotic Factors

There are many ways to describe living things.
Be sure you are familiar with the following
terms:
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Producer
Consumer
Herbivore
Carnivore
Autotroph
Heterotroph
Interactions of Biotic Factors

One example of interactions of biotic factors
is predation. An organism that consumes
others is called a predator and the organism
that it consumes is called its prey.
Interactions of Biotic Factors

Another example of interactions of biotic
factors is symbiosis which is a close, often
long-term, interaction between two different
biological species. This includes:
◦ Mutualism – both organisms benefit
◦ Commensalism – one benefits and the other
derives neither benefit nor harm
◦ Parasitism – one benefits at the expense of the
other.
Biodiversity
• Biodiversity refers to the number and variety
of species in a given area and it is always
changing! The number of known species on
Earth, for instance, is about 1.6 million, most
of which are insects. (This differs from the
actual number of species on Earth, which may
be closer to 13 million!)
Biodiversity = Sustainability

The greater the biodiversity (both in
different types of species and species
numbers), the more sustainable the
ecosystem.
Diverse, thus
Sustainable
NOT Diverse, thus
Difficult to Sustain
Biodiversity = Sustainability

Each species has a role or niche to play in
its ecosystem so when an ecosystem
changes, hopefully there will be some
organisms that possess adaptations or
genetic variations (from sexual
reproduction) enabling their species, or at
least some of their species, to survive.
Otherwise, the ecosystem may be in
jeopardy!
Sexual vs. Asexual Reproduction
Variety within a species is the result of
sexual reproduction.
 Having species richness and species numbers
is a good thing for sustainability.
 Asexual reproduction does NOT promote
biodiversity.
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Example of Biodiversity
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Mt. St. Helens’ Gopher. When Mt. St. Helens
volcano erupted in 1980, it devastated an entire
mountain of life; however, there was one
mammal that survived. A small furry gopher
species had tunneled underground and
eventually found its way to the surface, after
the lava cooled. Because this small gopher has
adaptations such as fast burrowing claws, and
did not require much food, it was able to
survive. Hundreds of other
gophers died in the devastation,
but this particular type survived.
Danger of Limited Biodiversity

The tundra is a very fragile environment.
It can only support a limited number of
consumers because its cold climate limits
the growing and reproduction cycles of
plants (the producers); therefore, there is
very LIMITED biodiversity. Should a
disaster arise (like melting of glaciers,
etc.), it could damage this fragile
ecosystem forever!