COMMUNITY / COMPETITION: ABIOTIC / BIOTIC FACTORS:
Community = the populations of di erent Abiotic factors = non-living factors of the
species in a habitat environment e.g. moisture, light intensity,
Ecosystem = the interaction between a temperature, CO2, wind, oxygen and pH
community of living and non-living parts of the Biotic factors = living factors of the
environment environment e.g. new predators, competition,
• plants need light, space, food, water and new pathogens, food availability
mineral ions to survive
• animals need territory, food, water and mates • A change in the environment could be an
• organisms compete with others for the same increase or decrease in an abiotic factor.
resources These changes can lead to a ecting
• within a community, each species depends population size
on another for things such as food, shelter, • A change in the environment could be the
pollination and seed dispersal introduction of a new biotic factor, which may
(interdependence) have e ects due to interdependence
• This interdependence means that any major
change can have extreme knock-on e ects
FOOD CHAINS: FACTORS OF FOOD SECURITY:
• Show whats eaten by what in an ecosystem Food security is having enough food to feed a
• Producers make glucose for photosynthesis and population. Things that can threaten food security:
other biological molecules, which are the plants • Population increase
biomass • Changing demands for certain foods
• Energy is transferred in an ecosystem when • New pests and pathogens
organisms eat other organisms • High farming input costs
Stable community: • Con icts
• If population of prey increase, then so will the • Accessibility to food and water
population of predators Sustainable methods of food production are
• If the predators increase, prey decrease needed so that enough food can be produced to
• Predator-prey cycles out of phase with each other feed the population.
FARMING TECHNIQUES: THE CARBON / WATER CYCLE:
Limiting movement of livestock and keeping them Water cycle:
in temperature-controlled environments reduces • Energy from sun causes evaporation, turning water into
energy transfer, so more energy is available for water vapour. Water also evaporates from plants
(transpiration). Water vapour carried upwards, and cools
food, so more meat can be produced. Examples are: and condenses to form clouds. The water then falls from
• Calves and chicken being raised in small pens the clouds as precipitation, where water is provided for
• Fish can also be factory farmed (kept in small plants and animals. It then drains into the sea and the
spaces) process repeats.
• Some animals are fed high protein food Carbon cycle:
Some of these methods can be quite controversial • CO2 removed from atmosphere from photosynthesis and
as disease can spread easier. The ethical issues are used for glucose. Some CO2 is released during
respiration. when the plants are eaten, the carbon can
that keeping animals in unnatural and uncomfortable
move through the food chain.When they respire, some is
conditions is cruel. released. When plants, animals and algae die,
• This is why other methods e.g. free range eggs microorganisms feed on the remains, and release Co2
are sometimes preferred by some customers as during respiration. The combustion of wood and fossil
they feel that it is better for the animals fuels releases CO2 back into the atmosphere. therefore,
the carbon and energy is being cycled - air, through the
entire food chain and then back into the air again.
ff
Community = the populations of di erent Abiotic factors = non-living factors of the
species in a habitat environment e.g. moisture, light intensity,
Ecosystem = the interaction between a temperature, CO2, wind, oxygen and pH
community of living and non-living parts of the Biotic factors = living factors of the
environment environment e.g. new predators, competition,
• plants need light, space, food, water and new pathogens, food availability
mineral ions to survive
• animals need territory, food, water and mates • A change in the environment could be an
• organisms compete with others for the same increase or decrease in an abiotic factor.
resources These changes can lead to a ecting
• within a community, each species depends population size
on another for things such as food, shelter, • A change in the environment could be the
pollination and seed dispersal introduction of a new biotic factor, which may
(interdependence) have e ects due to interdependence
• This interdependence means that any major
change can have extreme knock-on e ects
FOOD CHAINS: FACTORS OF FOOD SECURITY:
• Show whats eaten by what in an ecosystem Food security is having enough food to feed a
• Producers make glucose for photosynthesis and population. Things that can threaten food security:
other biological molecules, which are the plants • Population increase
biomass • Changing demands for certain foods
• Energy is transferred in an ecosystem when • New pests and pathogens
organisms eat other organisms • High farming input costs
Stable community: • Con icts
• If population of prey increase, then so will the • Accessibility to food and water
population of predators Sustainable methods of food production are
• If the predators increase, prey decrease needed so that enough food can be produced to
• Predator-prey cycles out of phase with each other feed the population.
FARMING TECHNIQUES: THE CARBON / WATER CYCLE:
Limiting movement of livestock and keeping them Water cycle:
in temperature-controlled environments reduces • Energy from sun causes evaporation, turning water into
energy transfer, so more energy is available for water vapour. Water also evaporates from plants
(transpiration). Water vapour carried upwards, and cools
food, so more meat can be produced. Examples are: and condenses to form clouds. The water then falls from
• Calves and chicken being raised in small pens the clouds as precipitation, where water is provided for
• Fish can also be factory farmed (kept in small plants and animals. It then drains into the sea and the
spaces) process repeats.
• Some animals are fed high protein food Carbon cycle:
Some of these methods can be quite controversial • CO2 removed from atmosphere from photosynthesis and
as disease can spread easier. The ethical issues are used for glucose. Some CO2 is released during
respiration. when the plants are eaten, the carbon can
that keeping animals in unnatural and uncomfortable
move through the food chain.When they respire, some is
conditions is cruel. released. When plants, animals and algae die,
• This is why other methods e.g. free range eggs microorganisms feed on the remains, and release Co2
are sometimes preferred by some customers as during respiration. The combustion of wood and fossil
they feel that it is better for the animals fuels releases CO2 back into the atmosphere. therefore,
the carbon and energy is being cycled - air, through the
entire food chain and then back into the air again.
ff
