Energy flow in ecosystems Flashcards
ecology
the study of living things and their interactions with each other and their environment
ecosystem
a self-supporting sysetm of organisms interacting with each other and their environment
habitat
a place within an ecosystem where specific organisms live, e.g. pond or woodland
population
all of the organisms of a particular species found in an ecosystem
community
all the different species living in an ecosystem
competeition
the struggle for resources
biotic factor
all biological (living) components of the ecosystem (predation, food, competition, decomposition)
abiotic factor
(all the non-biological components of the ecosystem (including water, air, temperature, sunlight, etc…)
producer
organism that can make its own food (= autotroph)
primary consumer
organism that obtains energy by feeding on producers (=heterotroph)
secondary consumer
organism that obtains energy by feeding on primary consumer (= heterotroph)
herbivore
animal that feeds on plants only
carnivore
animal that feeds on other animals only
tertiary consumer
animal that has no natural predators
prey
animal hunted and killed by another animal for food
predator
animal that preys on other animals
detritivore
organism that feeds on dead/ decaying organic material (e.g. worm vulture) (=saprotroph)
decomposers
organism that decompose (break down) organic material (e.g. bacteria + fungi)
heterotroph
organism that feeds on other organisms (= consumer)
autotroph
organism that can make its own food (= producer)
saprotroph
organism that feeds on decaying organic material (= detritivore)
food chain
shows simple feeding relationships within an ecosystem
food web
shows complex feeding relationships within an ecosystem
trophic level
stage in a food chain (= feeding level)
pyramids of number
represents the number of organisms in each trophic level in a food chain (irrespective of their mass)
pyramids of biomass
represents the total mass of all the organisms in each trophic level (irrespective of their number)
pyramid of energy
shows the energy transferred through each trophic level in a food chain
quadrat
a square frame (sometimes gridded) for sampling organisms
The organisms: leaf, worm, mouse, owl
Label their trophic levels
Whether their are a producer or consumer and which consumer they are (primary, secondary…)
Whether they are prey or a predator
Whether they are a herbivore or carnivore
leaf → worm → mouse →owl
trophic level 1 → trophic level 2 → trophic level 3 → trophic level 4
prodcuer → primary consumer → secondary consumer → tertiary consumer
(N/A) → herbivore → carnivore → top carnivore
(N/A) → prey → prey, predator → predator
What would happen if the fox population decreased? (two outcomes)
squirrel population increases
woodmouse population increases
What would happen if the caterpillar population decreased? (two outcomes)
shrew population decreases
earthworm population decreases
Food chains show the direction of … transferred between the trophic levels
Energy is transferred as … (in food molecules)
Chemical energy is stored as new … (mass of an organism)
Food chains show the direction of energy transferred between the trophic levels
Energy is transferred as chemical energy (in food molecules)
Chemical energy is stored as new biomass (mass of an organism)
The population of each organism in a food chain can be shown in a pyramid of …
The … of each box is determined by the number of organisms at each trophic level
The population of each organism in a food chain can be shown in a pyramid of numbers
The width of each box is determined by the number of organisms at each trophic level
Sketch a pyramid of numbers for this food chain:
50 clovers → 20 snails → 5 thrush → one sparrowhawk
The … of each trophic level in a food chain is shown in a pyramid of biomass
The biomass of each trophic level in a food chain is shown in a pyramid of biomass
Sketch a pyramid of biomass for this food chain:
oak tree → caterpillar → mouse → owl
(1 x 50kg) → (50 x 0.2kg) → (5 x 0.5kg) → (1 x 1kg)
oak tree → caterpillar → mouse → owl
(50kg) → (10kg) → (2.5kg) → (1kg)
Between each trophic in a food chain, not all energy is converted into new … in growth
Some … is …
Up to …% of energy can be lost in trophic levels
Between each trophic in a food chain, not all energy is converted into new biomass in growth
Some energy is lost
Up to 90% of energy can be lost in trophic levels
How is energy lost between each trophic level?
some energy is released in respiration (e.g. for movement or body heat)
not all energy is digested, some is excreted
some is converted into new biomass
not all of the organism is eaten
How can food production be made more efficient?
by decreasing the number of trophic levels in food chains
by limiting the movement of animals, so that less energy is lost
by increasing the temperature, so that less energy is lost through body heat - this is done by keeping the animals close together in a confined space