Transcript Priedas_1_Communities and ecosystems

Communities and ecosystems
Aidas Bertulis
2013, Šiauliai
Jurgita Šerniūtė
2013, Kaunas
THE MAIN AIM:
 To learn about communities and ecosystem.
OBJECTIVES:
 To learn about a food chain and the energy flow in a
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food chain.
To learn about a food web.
To find out what the trophic level is.
To recognize the pyramid of energy and to learn about
the way how energy enters and leaves ecosystems and
that nutrients must be recycled.
To do a topic-related task.
MAIN CONCEPTS
and Lithuanian equivalents
 Ecology – ekologija; gamtosauga.
 Ecosystem – ekosistema, ekologinė sistema.
 Population – populiacija.
 Community – (augalų, gyvūnų) bendrija, biocenozė
 Species – rūšis, atmaina; veislė.
 Food chain – mitybos grandinė.
 Food web – mitybos tinklas.
 Omnivore – visaėdis gyvūnas.
 Organic compound – organiniai junginiai.
 Habitat – arealas.
Definitions and examples (1):
 Ecology – the branch of biology that deals with the relations of
organisms to one another and to their physical surroundings.
 Ecosystem – a biological community of interacting organisms
and their physical environment: e.g. The marine ecosystem of
the northern Gulf has suffered irreparable damage.
 Population – a community of animals, plants, or humans among
whose members interbreeding occurs: e.g. fluctuations in
populations of voles.
 Community – a group of interdependent plants or animals
growing or living together in natural conditions or occupying
a specified habitat: e.g. communities of insectivorous birds
Definitions and examples (2):
 Species – a group of living organisms consisting of similar
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individuals capable of exchanging genes or interbreeding.
e.g. Homo sapiens.
Food chain – a series of organisms each dependent on the next
as a source of food.
Food web – a system of interlocking and interdependent food
chains.
Omnivore – an animal or person that eats a variety of food of
both plant and animal origin.
Organic compound – any member of a large class of gaseous,
liquid, or solid chemical compounds whose molecules contain
carbon.
Habitat – environment where species live.
TASK 1
Write a definition
for the given
concepts and
mach them to the
pictures.
Answers:
e. Species
a. Ecology
g. Food web
i. Organic
compound
b. Ecosystem
f. Food chain
j. Habitat
c. Population
d. Community
h. Omnivore
Trophic level
The trophic level of an organism defines the feeding
relationship of that organism to other organisms in a food
chain.
The energy flow in a food chain
a) Not all solar energy will come
into contact with chlorophyll and
will therefore not be trapped in
the synthesis of organic
compounds during
photosynthesis.
b) Photosynthesis in which light
energy is trapped by producers.
c) Consumers feeding and passing
on energy in the food molecules.
d) Loss of energy as heat
from respiration.
e) Death and the consumption of
dead organisms by detritivores.
Or as food not assimilated
because of incomplete digestion.
Pyramid of energy
•This model shows the typical loss of energy
from solar radiation through the various
trophic levels.
•Note how this causes the tapering of the
model.
•The volume of one layer is 10% of the layer
below.
•This is a more typical pyramid of
energy. Note that the initial solar energy
is not shown.
•The narrowing shape illustrates the
gradual loss of energy progressing along
the links of a food chain to higher tropic
levels (see above for detail)
Energy enters and leaves ecosystems, but
nutrients must be recycled
(a) Energy flows: this diagram is a simple version of the pyramid of energy.
At each trophic level energy is lost as heat. At the top of the pyramid of
energy it tapers to a point showing how all energy is ultimately radiated to
space as heat.
(b) Matter cycles: new matter is not created, no new carbon, hydrogen or
oxygen. Producers (autotrophs) take inorganic molecules and convert them
to organic compounds. Consumers feed at different trophic levels taking in
organic matter and using it for their own growth. This cycling of matter is the
subject of the carbon, nitrogen and water cycle.
TASK 2
ECOSYSTEMS, BIOMES, AND HABITATS
Read the text and write one or two questions for each
paragraph. Then exchange and answer each other’s
questions with a colleague.
A food chain
Bushgrass---> Impala ---> Cheetah----> Lion
• Food chains show a simple linear flow of “who eats who”
and therefore the energy and matter flowing through the
links in the chain.
A food web
The food web is a diagram that shows how food chains are
linked together into more complex feeding relationships.
http://www.soilfoodwebnewyork.com
A food web has a number of advantages over a food chains including:
•Shows much more complex interactions between species within a community/
ecosystem;
•More than one producer supporting a community;
•A single producer being a food source for a number of primary consumers;
•A consumer may have a number of different food sources on the same or
different trophic levels;
•A consumer can be an omnivore, feeding as a primary consumer and as a
consumer at higher trophic levels.
TASK 3: DESIGN A FOOD CHAIN FROM 5 OR MORE ORGANISMS.
Example:
References
Click4Biology: 5.1 Communities & ecosystems. Internetinė
prieiga: http://click4biology.info/c4b/5/eco5.1.htm
Oxfordo anglų kalbos žodynas. Internetinė prieiga:
http://oxforddictionaries.com/spellcheck/english/
Example:
HOMEWORK:
Design a food web from 15 or
more organism.
For both alternatives write names
and short definitions near
pictures. Prepare to present in
class (3-5 min.)