Unit 1-Ecology · Unit 1-Ecology Chapter 3-The Biosphere . Ecology Study of interactions among...
Transcript of Unit 1-Ecology · Unit 1-Ecology Chapter 3-The Biosphere . Ecology Study of interactions among...
Unit 1-Ecology
Chapter 3-The Biosphere
Ecology
Study of interactions
among organisms &
between organisms and
their environment
Ernst Haeckel
1866 coined word “ecology”
Based on oikos = “house”
Biosphere
The portion of the Earth that supports life
Composed of two parts:
1. Biotic factors – the living organisms that inhabit
an environment • All organisms depend on others directly or indirectly for food, shelter,
reproduction, or protection
2. Abiotic factors – the nonliving parts of an
organisms environment • Air currents, temperature, light, moisture
• Have effect on living things and often determine which species can survive
in an area
Levels of organization in ecology
In Ecology, we begin with the
individual and move through the
levels to the planet, Earth
Species
Group of organisms with similar characteristics
Able to breed and produce fertile offspring
Species Hybrid
Populations
Group of individuals
(of the same species)
that live in the same
area
Example?
All the fire ants in
a pasture
Community
Groups of different
populations that live
together
Examples?
All the ants, birds,
grass, cows, etc
in a pasture
Ecosystem
Collection of all organisms (biotic) that live in a particular area, together with their non-living (abiotic) parts of an environment
Examples of abiotic factors??
Climate, soil type, amount of rainfall, etc
Southern Pine Ecosystem
Fort Bragg, North Carolina
Levels of organization in an
organism
Chemicals make up cells…
Which make tissues…
Organs…
Systems…
And finally, the individual organism
Community Ecology
Habitat – a specific place where an organism
lives out his life
Niche – the role an organism
plays in the environment
Symbiotic Relationships – two
organisms living together
1. Competition (-/-)
compete for limited resource
Food, mate, territory
2. Predation (+/-) – Hunt and kill your prey
3. Parasitism (+/-)
4. Mutualism (+/+)
lichens (algae & fungus)
5. Commensalism (+/0)
barnacles attached
to whale
Symbiosis
Mutualism
The act of two organisms utilizing one another.
Both thrive and help each other.
Commensalism
The act of one organism utilizing another living
organism. One thrives and the other is neither
harmed nor helped
Parasitism
The act of one organism feeding upon another
living organism. The parasite thrives and the host
is harmed.
commensalism
predation competition
mutualism
+/0
+/+
+/-
-/-
Symbiotic Relationships
Herbivores (a.k.a. primary
consumers)
feed directly on
producers
Types of Consumers:
Carnivores (a.k.a.
secondary consumers)
feed on other animals
Types of Consumers:
Omnivores
feed on both plants
and animals
can be either primary
or secondary
consumers,
depending on food
chain
Types of Consumers:
Scavenger
an animal or other organism that feeds on
dead organic matter
Decomposers/Saprophyte/Detritivores
feed on (and recycle) dead or decaying matter
completing the chain, by returning nutrients needed by producers to the environment
Scavengers eat dead
things but do not recycle
Decomposers feed on dead
things AND recycle them
Types of Consumers:
Energy flow through the biosphere
Autotrophs (producers) organisms that make their own food
Heterotrophs (consumers)
Rely on other organisms for their food supply
What’s the ultimate source of energy for all life?
AUTOTROPHS
Water + CO2 Sugar + O2
HETEROTROPHS
Sugar + O2 water + CO2
Food chain
Series of steps in which organisms transfer energy by eating and being eaten
Arrow always points to the consumer
Food Chain
The pathway of
energy that
DECREASES as
it passes through
the trophic
(feeding)
levels Trophic level of an
organism is the position it
occupies in a food chain
Food web
Network of complex
interactions, linking
all of the food
chains together
Show ALL the
possible feeding
relationships
Many connections
throughout
ecosystem
Ecological Pyramids
Energy Pyramid
Biomass Pyramid
Pyramid of numbers
Hawk-eye Question: Why are they shaped as a pyramid?
What is the relationship between the numbers of
producers and Consumers?
How does this relate to the energy flow through the
ecosystem?
pyramid of numbers
So fewer and fewer
organisms can be
supported at each level
ONLY 10% of energy is passed on to next level Energy Pyramid
Biogeochemical cycles:
Water (hydrologic) cycle
Driven by solar energy
Recycles water, which is primary component of all life
Phosphorus
Cycle driven by decomposing
bacteria & fungi
phosphorus is an
important component of
ATP, Nucleic acids, &
phospholipids
Carbon Cycle The Carbon Cycle is driven
mainly by TWO processes:
Photosynthesis the process
by which producers convert
sunlight into a useable form
of energy
Cellular Respiration overall
process by which the body
gets and uses oxygen and
gets rid of carbon dioxide
CO2 in
Atmosphere
CO2 in Ocean
Nitrogen Cycle driven by decomposition by nitrifying bacteria and fungi
atmospheric nitrogen must be converted to a usable (by plants) form
N2 in Atmosphere
NH3
NO3 –
and NO2 –
Ecological Succession
IV. Ecological Succession transition in species composition over time
SLOW process, can take years or decades
usually occurs after a disturbance
Two types: Primary and Secondary
Mt. St. Helens
1. Primary Succession
Takes place over land where there are NO living organisms.
Ex. Bare rock, volcano created new island
Succession of Species
lichens & mosses grasses
trees bushes & small trees
pioneer species
climax forest
compete well in high sunlight
more shade tolerant species
shade tolerant species
stable community
2. Secondary Succession
Existing community cleared, but base soil
is still intact
Ex. Forest fire, harvesting, hurricane
burning releases
nutrients formerly
locked up in the
tissues of tree
the disturbance
starts the process
of succession
over again
IIV. Species diversity
• Greater biodiversity offers:
more food resources
more habitats
more resilience in face of environmental change
Greater diversity = greater stability