Ecology and evolution
Topic 5.1 Communities
and ecosystems
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
 Page
176, Question 5
 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”!)
Pyramid of numbers
Pyramid of numbers
An ecological pyramid of numbers shows the
population of each level in a food chain in a
pictorial form.
….but…..
Pyramid of numbers for a tree
…so we could use a pyramid of
biomass
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 m2yr-1) or calories per meter2 per year (cal m2yr-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)
Energy flows but Nutrients cycle
Light
Energy
Heat
Energy
Nutrients
An Ecosystem
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
Slide 18, 19 and 20 , - 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.
Slide 21 – Dead Bird - Namb Faro, http://namb-ualg.blogspot.com/2009_04_01_archive.html - 09.01,
16th September 2010.