Transcript Ecology and evolution

The Ecosystem
Topic 2.1 Structure
Some useful definitions:
 Species
– A group of organisms that
can interbreed and produce fertile
offspring.
 Eg. a lion
or a tiger
But………A lion and a tiger can
reproduce together and produce a Liger
Is the liger a new species? Are lions and Tigers the
same species?
No, because the liger is sterile.
Habitat – The environment
where a species normally
lives or the location of a living
organism. Homework:
Find out:
What is a niche?
How is it different
from a habitat?
A species share of a
habitat and the resources
in it. This depends not
only where the organism
lives but also what it does.
Population – a group of organisms
of the same species who live in the
same area at the same time.
What’s missing from this graph?
.........It has area
……..it has time
Community
– a group of
populations
living and
interacting
with each
other in an
area.
Ecosystem – A community and its
abiotic (non-living) environment
Ecology – The study of the
relationships between living
organisms and their relationships
with the environment
Living
(biotic)
things that
affect
Ecosystems
Non-living
(a-biotic)
factors that
effect
Ecosystems
Autotroph- An organism that
synthesises its organic molecules
from simple inorganic substances.
A plant yesterday.
Autotrophic bacteria
Heterotroph
– an organism
that obtains
organic
molecules
from other
organisms.
Saprotroph – an
organism that
lives on or in nonliving matter,
secreting
digestive
enzymes into it
and absorbing the
products of
digestion.
What do you call a mushroom that
buys you drinks?
A Fungi to be with!
Detritivore – an organism that
ingests non-living organic material.
A woodlouse
Food chains
The arrows represent
the flow of energy from
eaten to eater!
Producer
Primary
consumer
Secondary
consumer
Tertiary
consumer
Make food chains with the following
organisms:
A)
 Shark
 Minnow
 Zooplankton
 Phytoplankton
 Tuna
B)
•Lion
•Gazelle
•Grass
•Tick
•Ox-pecker (bird that
eats ticks)
What is the initial energy source for both chains?
Make sure the arrows go in the right direction.
Food webs
What is the trophic level of the:
Caterpillar? Primary consumer
Robin? 2o, 3o, and 4o Consumer
Owl?
Higher Level question:
What will happen to the resilience of a
food web if you increase the
complexity?
Homework
 Using
Clip art make a food web that
contains at least 10 named
organisms (common names are
acceptable but must be more than
“big fish” or “tree”!)
Interactions - Competition
When 2 or more living things
try to get the same resource.
Examples:
2 people on the last sweety,
Trees trying to get tall to get
the most light; peacocks
competing for 1 female, two
penguins competing for a
nest.
http://www.imaging-essentials.co.uk/Images/competition.gif
Interactions - Parasitism
An organism that
lives off another
organism (and
gains all or most
of its food) where
only one of the
organisms
benefits.
Generally the
host is harmed
but not killed.
(1) The hookworm latches on the walls of the colon with its sharp teeth where it feeds
on blood. (2) The tapeworm is the longest parasite. A mature adult can lay a million
eggs a day. (3) Tapeworm eggs embedded in the colon. (4) The roundworm can grow
to be 20 inches (50 cm) long and lay 200,000 eggs per day. (5) Pinworms migrate
outside the colon during the night to lay their eggs around the anus. This causes the
nightly itching of many unsuspecting victims.
http://www.lookgreat-loseweight-savemoney.com/images/common-parasites.jpg
Interactions - Mutualism
Where both
organisms of
different species
in an interaction
benefit from the
interaction.
http://cdn.webecoist.com/wp-content/uploads/2009/03/symbiotic-mutualism-animals.jpg
Interactions - Predation

http://www.bio.miami.edu/dana/pix/lion_predation.jpg
When a
secondary (or
higher)
consumer eats
another
consumer.
Interactions - Herbivory
 When
an animal eats a plant (a
primary consumer eats a producer.)
http://fireecology.okstate.edu/images/TGPP%20bison%20on%20patch3.JPG
Pyramids
Pyramids of Giza
Pyramid of numbers
Sparrow hawk
Starling
Sparrowhawk
killing a
starling
Snail on
lettuce
Snail
Lettuce
Pyramid of numbers
An ecological pyramid of numbers shows the population of
each level in a food chain in a pictorial form. The size of each
box represents the size of each population
….but…..
Pyramid of numbers for a tree
Aphid
Starling
Lacewing larvae
Starling
Elder tree
…so we could use a pyramid of
biomass
Starling
Pyramid of Biomass
An ecological pyramid of biomass shows what happens to
the amount of biomass at each trophic level by showing
how much living material there is at each trophic level of a
community at a specific time. Typical units for a biomass
pyramid could be grams per meter2 (gm-2), or calories per
meter2(cal m-2).
….but……
Dead bird
Not every part of an organism is digestable, the beak and
bones of a bird will not pass on to the next trophic level.
This can make a pyramid of Biomass look like it contains
more energy than it actually does.
…. So we could use a pyramid of
productivity.
An ecological pyramid of productivity is often
more useful, showing the production or
turnover of biomass at each trophic level.
Instead of showing a single snapshot in time,
productivity pyramids show the flow of energy
through the food chain. Typical units would be
grams per meter2 per year (g m-2yr-1) or
calories per meter2 per year (cal m-2yr-1) As
with the others, this graph begins with
producers at the bottom and places higher
trophic levels on top.
(Wikipedia - http://en.wikipedia.org/wiki/Ecological_pyramid - 09.10 – 16th September 2010)
Bioaccumulation

Bioaccumulation
refers to the build
up of chemicals,
such as pesticides
in an organism.
(USGS Toxic
Substances
Hydrology Program)
Bioaccumulation
occurs when an
organism absorbs a
toxic substance
faster than it can
lose it through
egestion or
excretion.
http://www.marietta.edu/~biol/102/2bioma95.html wwweb - 20thSeptember
2010, 13:10


Bioaccumulation: increase in
concentration of a pollutant
from the environment to the
first organism in a food chain
Biomagnification: increase in
concentration of a pollutant
from one link in a food chain
to another.
http://www.marietta.edu/~biol/102/2bioma95.html wwweb - 20thSeptember
2010, 13:10
Links
 Classic
example: DDT
 Classic example: Minamata
 Click
on the hyperlinks and Read
these articles!!!!!!
Images
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Slide 18 – Competition - http://www.imaging-essentials.co.uk/Images/competition.gif - 10.00, 21 September 2010
Slide 19 – Parasites - http://www.lookgreat-loseweight-savemoney.com/images/common-parasites.jpg - 10.01, 21
September 2010
Slide 20 – Mutualism - http://cdn.webecoist.com/wp-content/uploads/2009/03/symbiotic-mutualism-animals.jpg 10.02, 21 September 2010
Slide 21 – Predation – http://www.bio.miami.edu/dana/pix/lion_predation.jpg - 10.03, 21 September 2010
Slide 22 – Herbivory - http://fireecology.okstate.edu/images/TGPP%20bison%20on%20patch3.JPG - 10.04, 21
September 2010
Slide 23 - Pyramids of Giza – web - http://www.places-to-visit.us/files/images/The_Pyramids,_Giza,_Egypt_.png –
09.00, 16th September 2010.
Slide 24, 25 and 26 , - Pyramid of numbers; Pyramid of numbers for a tree; Pyramid of Biomass –
http://media.tiscali.co.uk/images/feeds/hutchinson/ency/0013n049.jpg - 09.01, 16th September 2010.
Snail lettuce - http://img1.photographersdirect.com/img/2658/wm/pd272617.jpg
Sparrowhawk killing a starling - http://img.dailymail.co.uk/i/pix/2008/02_04/1LifeDeathSWNS_800x571.jpg
Slide 25 – Aphid - http://somethingscrawlinginmyhair.com/wp-content/uploads/2009/09/aphid.rear.jpg
Lacewing larvae - http://entnemdept.ufl.edu/fasulo/woodypest/images/slide14.jpg
Elder tree - http://images.bidorbuy.co.za/user_images/651/390651_Nuxia_floribunda1.jpg
Starling Slide 27 – Dead Bird - Namb Faro, http://namb-ualg.blogspot.com/2009_04_01_archive.html - 09.01, 16th September
2010.
Slide 29 and 30 – Bioaccumulation - http://www.marietta.edu/~biol/102/2bioma95.html wwweb - 20thSeptember
2010, 13:10
Bibliography
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Evolution of man picture http://daily.swarthmore.edu/static/uploads/by_date/2009/02/19/evolution.jpg
Lion Picture http://bluepyramid.org/ia/lion.jpg
Tiger picture http://fohn.net/tiger-pictures-facts/tiger-regal.jpg
Liger picture http://img40.exs.cx/img40/8801/liger10jb.png
Habitat picture http://www.desertlion.info/photos/22-wend-1c6.jpg
Population graph
http://www.sustainablescale.org/images/uploaded/Population/World%20Population%20Growth%20to%
202050.JPG
Community picture http://media-2.web.britannica.com/eb-media/48/6548-004-4D277914.gif
Ecosystem picture http://www.scienceclarified.com/images/uesc_04_img0211.jpg
Tree Hugger http://www.treehuggersofamerica.org/images/tree_hugger.jpg
Autotrophic bacteria
http://www.college.ucla.edu/webproject/micro7/studentprojects7/Rader/pseudomo.gif
A plant yesterday http://mrgrassosclass.com/images/autotroph.jpg
T.rex picture http://www.biblelife.org/evolution-t-rex.jpg
Mushroom picture http://www.topnews.in/health/files/mushroom.jpg
Woodlice picture http://wpcontent.answers.com/wikipedia/commons/thumb/4/4b/Porcellio_scaber__male_front_2_(aka).jpg/250px-Porcellio_scaber_-_male_front_2_(aka).jpg
Food chain:
http://blogs.townonline.com/wellesley/wp-content/uploads/2008/07/cartoon-sun-thumb10088541.jpg
http://www.selfsufficientish.com/images/appletree.gif
http://bichitomalo.com/images/ist1_1035760_smiling_worm_cartoon.jpg
http://www.teachmecartoons.com/images/bird-cartoon.gif
http://www.floatingbanana.com/artbackwash/BlackHawk1.gif
Food web http://www.cals.ncsu.edu/course/ent425/images/tutorials/ecology/trophic_levels/foodweb.gif