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JANUARY 10, 2017
• TO DO: Notebook, pencil/pen, sit with
your groups
• WARM UP: Write all you know about the
different levels of the food web/food
chain.
• HOMEWORK:
• Vocabulary on Weebly Due Friday the
13th of January
• Contract due Monday 16th of January
INTRODUCTION TO
ECOLOGY
WHAT IS ECOLOGY
• The study of how
organisms interact
with their
environment
• All organisms must
interact with both
living and nonliving
things that surround
them
BASIC CONCEPT OF ECOLOGY
• The fundamental idea behind the study of ecology
is that all organisms are interdependent.
• They interact with one another and the physical
environment.
LEVELS OF ORGANIZATION
• To add to our list of the levels of
organization:
• Cells  Tissues Organs  Organ
Systems  Organisms  Population
 Community  Ecosystem 
Biosphere
LEVELS OF ORGANIZATION
• Ecologists tend to label groups of organisms.
• Let’s look at a familiar setting for example: Your
house is part of a town, this is part of a state,
which is part of a country, which is part of a
continent.
LEVELS OF ORGANIZATION CONT.
• No individual organism lives completely on its
own. It may live with other individuals of the
same species to form a population.
• Several populations living together make up a
community.
• Several communities in a given area make up a
biome.
ORGANIZATION CONT.
• Collectively, all the biomes of the planet earth
make up the biosphere.
• Again, the most basic level of
ecological organization is the individual/species.
• A group of individuals of the
same species make up a population.
• A community is all the
populations of living
organisms in an area.
LEVELS OF ORGANIZATION
ORGANIZATION CONT.
• The boundary of a community is
determined by the
distribution of its members.
• The boundary of one
community is not
necessarily the boundary
of another community.
We say these
communities overlap.
ORGANIZATION CONT.
A biome is a large geographical area with a similar
climate.
BIOSPHERE
The biosphere is the region on Earth where all life
exists.
THE ENVIRONMENT
• Made up of all the
living and nonliving
things that surround
an organism.
• Vocabulary:
• Abiotic Factors
• Biotic Factors
TWO PARTS OF AN ECOSYSTEM
BIOTIC AND ABIOTIC
• Biotic –
• factors that are or were alive/living in an ecosystem.
• Examples: animals, plants, insects, bacteria,
fungi, and dead organisms.
ABIOTIC
• Factors in an environment that are not or never
were alive.
• Examples: rock island, gases, water, sun,
minerals and temperature.
ENVIRONMENT VS HABITAT
• Many species can
survive in more than
one environment.
• But each species
has its “home” or
habitat.
• Fish may be able to
live in fish tanks, but
would rather live in
the wild
HABITAT AND NICHE
• Each organism confronts the challenge of survival
in a different way.
• The niche an organism occupies is the sum of all
the ways it utilizes the resources of its
environment.
• Part of this role may be played as the predator
and part may be played as the prey.
NICHE
Example: Snakes eat mice and other birds and
rodents but snakes are also eaten by birds of prey
and mice eat grasshoppers and other insects.
NICHE
• A niche may be described in terms of space
utilization, food consumption, temperature range
and mating requirements.
• An organism’s niche would also take into
account its behavior. You can think of an
organism’s niche as its job/role in the
environment.
NICHE
• A beaver is an ecosystem engineer. It
cuts down trees and dams up a river
which will flood the forest with a pond.
Eventually the trees will dies, new species
of plants and wildlife will arrive to take
advantage of the new conditions.
Eventually, this forest will become a
meadow. The beaver’s NICHE is the role
it plays in shaping the environment. But…
it is also a main prey species for
predators.
HABITAT
• Niche is not synonymous with habitat.
Habitat is a place, niche is a pattern of
living. Habitat is the address and niche is
the job or occupation.
• If two organisms have the same habitat
and similar niches, they will compete with
each other over the available resources.
(food- water -shelter)
COMPETITION
• An important
aspect of the
struggle for survival
involves
competition for
limited resources
•
•
•
•
Food
Water
Shelter
Sunlight
HABITAT
• Competition is the struggle between two
organisms within their habitat.
• If a species can avoid competing they may
co-exist. But if they compete, one will
eventually drive the other out of the
habitat, unless they have slightly different
niches.
• Example: times of activity
DIFFERENT NICHES TO AVOID
COMPETITON:
• Nocturnal – active at night
• Diurnal - active during the day
• Crepuscular – active at dawn and dusk
DIFFERENT NICHES TO AVOID
COMPETITON: CONT…
• Migration – moving from one area to another to
use resources
• Hibernation – reducing activity severely for a
period of time.
ECOSYSTEM
• An interacting system that consists of groups of
organisms and their non-living environment with
in a boundary.
Oligotrophic Lake: Nutrient poor, water is clear,
oxygen rich; little productivity by algae, relatively
deep with little surface area.
Eutrophic lake: nutrient
rich, lots of algal
productivity so it’s
oxygen poor at times,
water is murkier  often a
result of input of
agricultural fertilizers
Rivers and Streams: Organisms need adaptations
so that they are not swept away by moving water;
heavily affected by man changing the course of
flow (E.g. dams and channel-straightening) and by
using rivers to dispose of waste.
Wetlands: includes marshes, bogs, swamps, seasonal ponds. Among richest
biomes with respect to biodiversity and productivity. Very few now exist as they
are thought of often as wastelands.
Estuary: Place where freshwater stream or river merges with the ocean. Highly
productive biome; important for fisheries and feeding places for water fowl.
Often heavily polluted from river input so many fisheries are now lost.
Intertidal Zone: Alternately submerged and
exposed by daily cycle of tides. Often
polluted by oil that decreases biodiversity.
Coral Reefs: occur in neritic zones of
warm, tropical water, dominated by
cnidarians (corals); very productive,
protect land from storms; most are
now dying from rise in global
temperatures
Deep-sea vent: Occurs in benthic zone; diverse, unusual organisms; energy
comes not from light but from chemicals released from the magma.
Tropical Forest: Vertical stratification with trees in canopy blocking light to
bottom strata. Many trees covered by epiphytes (plants that grow on other
plants).
Example of Tropical, Dry Forest
Desert: Sparse rainfall (< 30 cm per year), plants and animals adapted for water
storage and conservation. Can be either very, very hot, or very cold (e.g.
Antarctica)
Chaparral: Dense, spiny, evergreen shrubs, mild rainy winters; long, hot,
dry summers. Periodic fires, some plants require fire for seeds to
germinate.
Temperate Grassland: Marked by seasonal drought and fires, and grazing by
large animals. Rich habitat for agriculture, very little prairie exists in US today.
Temperate Deciduous Forest: Mid-latitudes with moderate amounts of
moisture, distinct vertical strata: trees, understory shrubs, herbaceous substratum. Loss of leaves in cold, many animals hibernate or migrate then.
Original forests lost from North America by logging and clearing.
Coniferous forest: Largest terrestial biome on earth, old growth forests
rapidly disappearing, usually receives lots of moisture as rain or snow.
Tundra: Permafrost (Permanent frozen ground), bitter cold, high winds and
thus no trees. Has 20% of land surface on earth.
CLIMATE
• Definition?
• The overriding factor that determines the general
nature of an ecosystem.
If the climate is always hot and dry, the soil will
be sandy. The plants, animals and other life will
be specially adapted for survival in a desert.
CLIMATE CONT.
• If the climate is hot and moist, then there will be
many trees, characteristic of a Rainforest. Some
animals and insects will be adapted for living in
trees. They are called arboreal and include
monkeys and spiders.
PREDATOR – PREY RELATIONSHIP
• Predators are a
biotic limiting factor.
• They control
population size by
feeding on prey.
• There is a delicate
balance that needs
to be maintained.
KEY IDEA
• All organisms have
the ability to
produce
populations of
unlimited size
• But their
environment keeps
their numbers in
check.
CATEGORIES OF POPULATIONS
• Populations are
labeled by the
function they serve
in the ecosystem
• Producers
• Consumers
• Decomposers