Adaptations, interdependence and competition .1

what is an ecosystem

• the interaction between a community of living organisms and their environment.

what is a community

two or more populations of organisms.

what is a population

all the organisms of the same or closely-related species in an area.

Levels of organisation within an ecosystem

• Producer

• Primary consumer

• Secondary consumer

• Tertiary consumer

what are the producers

plants + algae which photosynthesise

what are the primary consumers

herbivores which eat producers

what are the secondary consumers

carnivores which eat primary conusmers

what are the tertiary consumers

carnivores that eat secondary consumers

what is the top animal in the feeding relationship called

apex predators

If the population of one organism rises or falls…

then this can affect the rest of the ecosystem

example of a simple food chain

grass → rabbit → fox

if foxes were killed what would happen to the rabbits and grass

• population of rabbits would increase bc they are no longer a prey to the foxes

• grass would decrease bc increase of rabbits would be eating it

what is interdependence

refers to the fact that all organisms living in an ecosystem depend on each other

competition - plants

all photosynthesising plants and algae in an ecosystem compete for light, space, water and minerals from the soil

competition - animals

compete for food, mates + their territory

what happens to organism that have more resources

tend to grow more healthy and more likely to have off spring

what two things can competition be

• interspecific (competition between organisms not in the same species.)

• or intraspecific (competition between organisms within the same species.)

what is a stable community

one where the size of the population of all species remains constant over time

what is the number of organisms in an ecosystem and their distribution is affected by

• abiotic factors

• These are factors that are non-living

what are some examples of abiotic factors (8)

• light intensity

• temperature

• moisture levels

• soil pH content

• soil mineral content

• Wind intensity and direction

• Carbon dioxide levels for plants

• Oxygen levels for aquatic animals

light intensity

• some plants have evolved for optimum growth in bright sunlight (eg. cactus)

• whilst other have evolved for optimum growth in shade (eg. many orchids)

• if you were to put these two plants in opposite environments they wouldn’t grow very well + eventually die

temperature

• both animals and plants have evolved ti grow healthily at their optimum temperatures

• eg. polar bears in very cold areas and cactus in hot areas

moisture levels

• many houseplants are killed by ppl overwatering/under-watering them

• many plants cannot survive in waterlogged soils - roots unable to respire + they rot + plant dies

• other plants (eg. pitcher plants) grow best where moisture levels are high

• use a soil moisture meter to determine accurately how wet an area is

soil pH content

• pH of soils have huge affect on plant grown on them

• some plants (eg. azaleas) grow best in acidic soils + will quickly die if placed in alkaline soils

• some can grow in both (eg. hydrangea) - flower colour changes in soil

• (just like universal indicator paper) hydrangea flowers are blue in acidic soils and pink in alkaline soils.

• also Different species have evolved to survive at different pH levels found within water.

soil mineral content

• many plants require high levels of soil minerals to grow (eg, magnesium required to produce chlorophyll)

• plants w unnaturally yellow leaves may have a magnesium deficiency.

• Carnivorous plants (eg. pitcher plants) have evolved to catch insects to supplement the low levels of minerals found in the soils in which they grow.

wind intensity and direction

• has huge impact on where organisms are found within ecosystems

• many organisms prefer more sheltered locations - plant seed more likely to germinate + animals will live close to plants they depend on

• strength of the wind can also affect the growth of individual organisms

Carbon dioxide levels for plants

• reactant in photosynthesis so plants need it to survive

• Areas with higher levels of carbon dioxide are more likely to have healthy plants growing.

• Farmers often release carbon dioxide within their greenhouses to maximise their crop yield

• Woodlands often have higher carbon dioxide levels than open grassland, so many plants living in open areas have evolved mechanisms to overcome a shortage of carbon dioxide.

Oxygen levels for aquatic animals

• Oxygen from the air and oxygen produced by aquatic plants dissolves in water.

• Without this, aquatic animals would suffocate and die.

• Healthy lakes and rivers = high levels of oxygen

• polluted waters = low levels of oxygen

• pollution → certain species can survive there such as sludgeworms

what are bioindicator species

their presence or absence informs us about the condition of the habitat.

what is the abundance and distribution of organisms affected by

• biotic factors

• living factors

examples of biotic factors

• Availability of food

• New predators

• New pathogens

• Out-competition

availability of food

• major factor in ecosystem - all animals require food

• areas like forests have more species of life as its got more rich food supply than deserts/polar regions

new predators

• can have a devastating affect

• In balanced ecosystems, predators and prey have evolved together.

• Predators can catch enough prey to survive, but not so many that they kill all of their food.

• Introducing new predators can cause a rapid decline in the numbers of prey, which then reduces the food supply for existing predators.

new pathogens

• When organisms inhabit new ecosystems they often bring new pathogens

• eg, when europeans visited native americans + introduced viruses meaning lots died

• Pathogens have also been introduced on purpose

• eg. Myxomatosis(disease affecting rabbits) cause to develop skin tumors + blindness

• purposefully released to reduce the population of rabbits + many died

• but devlop immunity and population returned to previous levels

Out-competition

• introduction of a new species into an ecosystem can result in it out-competing another native species

4 competitions of plants

• Light

• water from soil

• mineral from soil

• space

light

• plants + algae need light for photosynthesis

• competition for light as they grow quickly to reach it + shade other plants

• old tree dies in forest there is a rave to fill gap in canopy

water from soil

• reactant in photosynthesis so essesential

• some fully grown trees eg. oak tree lose 150L of water every day + its used to transport minerals through the plant to leaves

• Some plants have roots that are shallow but extend a long way from the tree to maximise the update of water after rainfall

• Others have roots that are deep to find stores of underground water

minerals from the soil

• require minerals for healthy growth

• include nitrate + magnesium

• Without sufficient minerals plants suffer deficiency diseases because they cannot grow healthily

space

• require space for healthy growth

• means their leaves are not shaded which maximises photosynthesis

• very close planted = much smaller growth

• Competition can be intraspecific, eg. competition between oak trees in a forest, or interspecific such as when another species of tree like birch or yew grew next to oak trees.

• when older tree dies, younger trees compete to replace it

• species that cannot compete effectively are unlikely to reproduce, and may die - known as survival of the fittest

3 competition in animals

• food

• mates

• territory

food

• all need food providing them with energy and raw materials to complete life processes

• Because food is so vital, many animals will fight for it.

mates

• within a species compete for mates

• essential to pass on their genes to their offspring

• evolved to have an innate or natural drive to reproduce - often results in fights

• these fights competing for mates can often result in serious injury or death, but benefits the population as only the strongest pass on their genes to the next generation

territory

• territory contain all of the resources and conditions they need to survive

• These include abiotic factors + biotic factors

An example of intraspecific + interspecific competition over territory

• intraspecific - be between lions on the grass plains of Africa

• interspecific - occur when another predator like leopards lived close to the lions.

what can Plant adaptations be

• structural

• behavioural

• physiological

what do all adaptations mean

• make organisms better suited to their ecosystem

• provide them with a better chance of survival and reproduction, which are their ultimate aims

what are adaptations that arise from competitions essential for

• the process of evolution

• survival of the fittest mean the survival of those best adapted

Structural adaptations in plants

• these are physical features allowing plants to compete

• eg. formation of spines in cacti + roses stop a plant from being eaten by grazing animals

• another example, is animals with shallow roots to absorrb lots of water after rain

Behavioural adaptations in plants

• these are behaviours which give them an advantage

• eg, plant root grow toward light to maximise photosynthesis - ensures they can respond to changes in thier environment

• others have evolved structural and behavioural adaptations to catch insects eg. venus fly tap - flytrap itslef is structural and closing of the trap to catch insect is behavioural

Physiological adaptations in plants

• are processes which allow them to compete

• eg.the formation of poisons for defence - deadly nightshade, are so poisonous they can kill if consumed by humans.

Structural adaptations in animals

• physical features which allow them to compete

• eg. sharp claws to catch prey, dig burrows or scratch trees to signal territories. The scratching of trees is a behavioural adaptation.

• Predators and prey often have similar adaptations :

  • Both are likely to have good vision and hearing.

  • Prey often has eyes on the sides of their heads to easily spot predators.

  • Predators often have their eyes on the front of their heads to judge distance to their prey.

Behavioural adaptations in animals

• behaviours which give them an advantage

• eg, mating rituals, like a male peacock bird showing his tail feathers to attract a female mate.

• eg. working together in packs like wolves to hunt prey

• eg. using tools - crocodiles use twigs to lure birds, who would pick them up to build nests.

Physiological adaptations in animals

• processes which allow them to compete

• eg. production of venom that snakes and spiders have to defend themselves and kill their prey

what is an extremophile

an organism that lives in an extreme environment

The organisms that live in these places have …

highly specialised adaptations

The Polar Regions info

• north pole - artic

• south pole - antarctic (no polar bear but penguins)

• both extremely cold - average : -40 degree celcius

• in Northern hemisphere summer the North Pole has has 24 hours of daylight and the South Pole experiences 24 hours of night. This is then reveresed during the Northern hempisphere winter.

north pole animals + adaptations

• polar bears have thick white fur for insulations + camouflage

• have acute sense of smell + sight to hunt prey

• small sa:v ratio to minimise heat loss

• thick layer of fat to keep warm

south pole animals + adaptations

• male Emperor penguins have evolved to insulate their egg on their feet throughout winter

• This is a behavioural adaptation

what are Deep sea volcanic vents

places on the ocean floor where the volcanic gases of underground magma chambers bubble through.

how do species exist in Deep sea volcanic vents

• bacteria feed on the chemicals released from the volcanic vents.

• Worms feed on the bacteria, and then other species feed on the worms

• These ecosystems are unique on Earth.

• adaptations of these animals allows them to survive in these conditions