TERMINOLOGY.
ABIOTIC: NON-LIVING EG WATER, STONES, NUTRIENTS
BIOTIC: LIVING EG CRAYFISH, FROG, CAT-TAIL, ALGAE,
BACTERIA
BIOTOPE/HABITAT: THE SPACE WHERE AN ORGANISM
LIVES EG A FOREST FOR A SQUIRREL, A POND FOR A
FROG
POPULATION: THE NUMBER OF INDIVIDUALS OF THE
SAME SPECIES LIVING IN THE SAME SPACE AT THE
SAME TIME EG ALL THE FROGS IN THE POND
COMMUNITY: ALL THE POPULATIONS IN AN
ECOSYSTEM EG THE FROGS, CRAYFISH, ALGAE ETC IN
THE POND
ECOSYSTEM: THE COMMUNITY AND THE ABIOTIC
FACTORS IN AN AREA INTERACTING WITH EACH OTHER
EG A POND, A RAINFOREST
PRODUCER: AN ORGANISM THAT MAKES ITS OWN
ENERGY. IT IS FOUND ON THE LOWEST TROPHIC LEVEL
IN A FOOD CHAIN. EG PLANTS
AUTOTROPH: AN ORGANISM CAPABLE OF PRODUCING
ITS OWN ENERGY (IN THE FORM OF ORGANIC
MOLECULES) FROM INORGANIC MOLECULES USING AN
EXTERNAL ENERGY SOURCE
EG GREEN PLANTS, SOME FLAGELLATES, ALGAE, SOME
BACTERIA
CONSUMER: AN ORGANISM, WHICH EITHER FEEDS ON
PRODUCERS OR OTHER CONSUMERS. IT OCCUPIES
TROPHIC LEVEL 2 AND ONWARDS IN A FOOD CHAIN.
EG A LEMMING, A WOLF
HETEROTROPH: AN ORGANISM INCAPABLE OF
PRODUCING ITS OWN ENERGY, EG ANIMALS, FUNGI,
SOME PROTISTS, SOME BACTERIA
DECOMPOSER: AN ORGANISM THAT BREAKS DOWN
DEAD MATTER, EG. EARTHWORMS
NB! THERE ARE DIFFERENT TYPES OF DECOMPOSERS,
IE DETRITIVORES, WHICH EAT DEAD MATTER, AND
SAPROTROPHS, WHICH USE EXTRA-CELLULAR
DIGESTION TO OBTAIN THEIR FOOD.
PARASITES: STEAL ENERGY FROM A HOST, BUT ARE
NOT PRIMARILY INTERESTED IN KILLING THEIR HOST
AS THAT WOULD KILL THE PARASITE AS WELL, EG THE
TAPEWORM (= binnikemask, lapamato) IN HUMANS AND
MISTLETOE
HERBIVORE: PLANT EATER (VORE = EATER), EG
RABBITS, LEMMINGS, ANTELOPE
CARNIVORE: MEAT EATER, EG LIONS, WOLVES
OMNIVORE: “ALL EATER”, IE IT EATS BOTH PLANTS AND
ANIMALS, EG HUMANS, BROWN BEARS
FOOD CHAIN: SHOWS HOW THE NUTRIENTS (IE THE
FOOD) ARE MOVING THROUGH THE ECOSYSTEM. TO
PUT IT BLUNTLY, IT SHOWS WHO EATS WHOM.
FOOD WEB: IS MORE COMPLEX, AND CONSISTS OF
SEVERAL FOOD CHAINS
BIOSPHERE: THE PARTS OF EARTH THAT CONTAIN LIFE.
TERRITORY: (= revir, reviiri) THE AREA AN INDIVIDUAL OF
AN ANIMAL SPECIES WILL PROTECT FROM OTHER
INDIVIDUALS OF THE SAME SPECIES OR FROM OTHER
SPECIES. SOME SPECIES ARE MORE PROTECTIVE OF
THEIR TERRITORY THAN OTHERS.
ECOLOGICAL NICHE: (ekologisk nisch, ekologinen lokero) IT
IS A LIMITED SPACE LIMITED BY ALL THE MOST
IMPORTANT ENVIRONMENTAL FACTORS, AND WITHIN
THAT SPACE THE INDIVIDUALS OF A SPECIES (OR OFTEN
RATHER A POPULATION) LIVE, GROW AND REPRODUCE.
THE ECOLOGICAL NICHE OF A SPECIES GIVES ITS PLACE
IN THE ECOSYSTEM AND FUNCTIONAL RELATIONSHIPS
TO OTHER ORGANISM AND THE ABIOTIC
ENVIRONMENT. THERE CAN BE ONLY ONE SPECIES PER
ECOLOGICAL NICHE. (It is often explained as an organism’s
job.)
ENERGY FLOWS THROUGH THE ECOSYSTEM
 Primary production: the entire amount of organic material, which plants
produce during a certain time period, usually a year. It can be expressed either
as:
1) gross production ie all organic material that plants in a specific area assimilate
eg during one year or during a vegetation period
2) net production which is gross production – respiration. This basically means
that net production is what is left for the consumers.
 Energy is transported in food chains. The lowest level of a food chain is known
as trophic level 1. This is where producers exist. Producers are eaten by
primary consumers, which are also known as 1st level consumers. These
primary consumers are (needless to say) herbivores, and their trophic level is 2.
Trophic levels 3-5 (there are very rarely more than 5 trophic levels) are filled
by carnivores known as secondary consumers a.k.a. 2nd level consumers (=
trophic level 3, ie tl 3), tertiary consumers a.k.a. 3rd level consumers (=tl 4) and
quaternary consumers a.k.a. 4th level consumers (= tl 5).
 In order to show how the energy moves through the ecosystem one uses both
food chains and food webs. Your job is to try to produce 2 food chains with at
least 4 species in each one. Remember that a food chain shows how the energy
moves using arrows, and that the arrow should be pointing towards the
organism that is eating, because that is where the energy (=food) is going. You
should have a producer at the lowest trophic level! One food chain should be
terrestrial, the other water based (marine or fresh water).
 The problem with food chains and food webs (we’ll do some when I return) is
that they don’t show amounts of individuals. This problem can be overcome by
using ecological pyramids, which can show different things about the
ecosystem
1) amount of energy
2) the total amount of individuals in each trophic level (This is clearly an
estimate!)
3) the total amount of living material ie., the biomass
For an example of a (simplified) food chain see the next page. Please note that one
should use actual species names, not just “plant”, “bird”, “predatory bird”, “larger
fish” etc. However, sometimes it is acceptable to write the species to family level, as
in the case of grass.
Trophic level 4
Tertiary consumer
hawk (it would be better with an actual species)
↑
Trophic level 3
Secondary consumer
Trophic level 2
Primary consumer
Trophic level 1
Producer
blue tit
↑
oak caterpillar
↑
oak