Flashcards in Ecology Deck (93):
The study of how organisms interact with each other and with their non-living surroundings.
The factors that affect an organism's chances of survival over it's lifetime
The place where the organisms and the physical surroundings form an environment that are different from other environments nearby.
What are the components of an ecosystem?
Abiotic and biotic factors.
Define a natural ecosystem.
An ecosystem that can exist on its own without outside help from humans.
Define an artificial ecosystem.
An ecosystem that is created by humans that need to be constantly managed.
Define abiotic factors and provide examples.
Non-living physical factors. E.g. water, temperature, fire, light, soil type, oxygen levels, etc.
Define biotic factors and provide examples.
Living factors. E.g. predators, parasites, infectious bacteria and viruses, wastes, etc.
Why is water important?
Water is a solvent for all materials in cells, and they allow chemical reactions to occur by acting as a transport.
How do animals lose water?
Aquatic animals lose water through diffusion and land animals lose it through evaporation.
How do land animals reduce water loss?
They become nocturnal, the cool temperatures reduce evaporation.
Water provides buoyancy. How does this affect animals?
Marine animals require less support than land mammals do, but transport through water is slow so marine animals have adapted their bodies to be streamlined in order to minimise water resistance.
How is temperature important?
Temperature affects the speed of chemical reactions in the cells. As temperature increases, the rate of reactions do too.
Ectothermics are a type of organism that must obtain heat from their environment because they can't generate heat internally through body chemistry.
How do ectothermics regulate their body temperature?
By lying on warms rocks in the sunlight to warm up or hiding in burrows to cool down.
Endothermics are organisms that have the ability to generate heat internally and control heat loss.
How are bushfires started?
Through lightning, arson, accidentally lighting a fire, and controlled purposeful fires.
Why are bushfires (purposefully) started?
To control and improve the growth of plants.
How do plants benefit from bushfires?
While some plants die, other plants are helped. Some plants flower better after fires, some plants drop their seeds, and some plants will germinate in response to the chemicals released from the smoke.
Why is light important?
Light is necessary for photosynthesis.
The process by which plants manufacture their food through the use of many materials.
What is the word equation for photosynthesis?
carbon dioxide + water -----sunlight-----> glucose + oxygen
What does light affect?
-Most plants will grow better with more light.
-As daylight gets longer form winter to spring, plants are influenced to flower.
-animal behaviour (rock lobsters avoid bright moonlight, etc.)
Why is soil type important?
Soil provides plants with water and minerals.
How do different soils differ?
Mineral content, water-holding ability, and acidity.
Which nutrients are needed by plants?
Nitrate and phosphate.
How does loam soil and sandy soil differ?
-loam soil contains more nutrients than sandy soil because the clay particles in loam have more plant nutrients than sang grains.
-fertilisers stick to the clay particles in loam whereas in sandy soil, it is easily washed off.
-loam holds onto water more strongly than sandy, meaning plants find it harder to extract the water it needs from loam.
Why is oxygen important?
Organisms require oxygen to carry out respiration.
What is the availability of oxygen to animals?
Land animals have enough oxygen in the air whereas aquatic animals have to depend on the amount of oxygen dissolved into the water.
What factors affect how much oxygen is dissolved in water?
-Temperature; there is more oxygen dissolved in cold water than warm water.
-Movement; water with more movement has more dissolved oxygen.
-Depth; the deeper the water, the less dissolved oxygen.
What disadvantages do animals living on the ocean floor have?
Animals who live at such deep depths are slow because of the limited energy provided by respiration due to the lack of oxygen.
The different interactions between living organisms.
The relationship between organisms where each affects the other's survival.
All the living things in an ecosystem.
Define competition and provide an example.
Organisms that try and obtain the same limited resource. E.g. baby birds compete with each other for food to attract their mother's attention.
Define predation and provide an example.
Where one organism (predator) kills and eats another (prey). E.g. preying mantis praying on a cricket.
Define mutualism and provide an example.
Where two organisms live closely together and both benefit. E.g. cleaner shrimp that eat parasites on the skin of fish.
Define parasitism and provide an example.
Where on organism benefits (parasite) and the other is harmed (host). E.g. a parasitic wasp that lays its eggs on a caterpillar, and when the eggs hatch, they eat the caterpillar.
Define commensalism and provide an example.
Where one organism benefits and the other is unaffected. E.g. whales and the barnacles it carries.
Define an adaption.
Any feature that assists an organism to survive and reproduce in its environment.
Define a structural adaption and provide an example.
Body parts that help an organism to survive. E.g. the wings of a bat helps it for hunting flying insects.
Define a behavioural adaption and provide an example.
A helpful habit, action, or feature that an organism displays. E.g. bats emit a clicking noise when hunting to locate insects.
What is the most common environmental change?
Seasonal changes in abiotic factors, e.g. in summer there is longer daylight.
How do abiotic factors affect biotic factors?
the changes in abiotic factors affect the plant matter which affect the herbivores which affect the carnivores.
Define birth rate and how environmental changes affect it.
The number of individuals born per thousand of population. When food is plentiful, adults have more energy and breed. Supple food is available to both the adults and offspring.
Define death rate and how environmental changes affect it.
The number of individuals who die per thousand of population. The exposure to unusually low temperatures kill many organisms.
Define immigration and how environmental changes affect it.
The number of individuals moving into an area per thousand of the population in the area. Animal immigrate when there are more resources such as food or water.
Define emigration and how environmental changes affect it.
The number of individuals moving out of an area per thousand of the population in the area. Animals emigrate when the do not have enough food or water.
When an ecosystem had the ability to maintain suitable living conditions for the community.
What does an ecosystem need to sustain itself?
-substances necessary for survival and growth
-an input of energy (sunlight)
-wide range of species living in the ecosystem
Organisms that make food for the community.
An organism in a food chain that feeds on other organisms.
How is glucose used in plants?
-used to make all other materials that plants need (proteins, nutrients and fats).
-turned to starch and stored in leaves and seeds until needed.
Define a food chain.
A diagram showing the sequence of organisms feeding on each other.
What do the arrows represent?
The arrows in the diagram show the direction in which energy travels.
Define a food web.
All the interconnected food chains in communities.
Organisms (bacteria and fungi) that break down dead bodies and waste, and recycle matter for producers to re-use
Why are decomposers important?
Without decomposers, ecosystems would run out of resources.
Why do organisms eat food?
-to build new cells for growth and repair.
-to provide energy for movement and processes.
How is energy transferred.
The 10% of energy that is used to build new cells is transferred to the consumer that eats the organism that previously had that energy. Only 10% of the original energy is transferred because the other 90% of it was used for movement and other processes.
Why are there limited high order consumers?
Because so much energy is lost through food chains, that there is not enough energy available to keep high numbers of high order organisms alive, and these organisms need to consume a lot in order to receive sufficient energy.
How does a pyramid of energy work?
a diagram that shows the energy in the food materials at each level in the food chain.
How does a productivity pyramid work?
The diagram shows how much energy is used per square meter by each feeding level in a year.
Refers to the number of different species in an ecosystem. A biodiverse ecosystem while have large numbers of many different species with a range of different characteristics.
Why is it a good thing for an ecosystem to be biodiverse?
The ecosystem will likely continue over time, it will not collapse, most species will survive and continue to be part of the food web, and it is less likely to be disrupted by environmental changes.
How will being biodiverse stop an ecosystem from collapsing?
The loss of one food source is not a disaster because there are other food sources available.
How will being biodiverse stop an ecosystem from being disrupted by environmental changes?
Because weeds and other introduced species would not be able to out-compete all the competitors in the ecosystem because there are so many.
How do interactions in a food web contribute to the stability of ecosystems?
When there is a large amount of an organism, it's predator will grow in size because of the abundance of food, but then the prey would go down in numbers because it's getting consumed so often, which then results in the numbers going down for the predator because there isn't enough food, and then the organism starts growing in size again, and so it goes.
List the reasons why people choose to protect ecosystems.
Cultural value, economics, survival and compassion.
How is cultural value a reason to protect ecosystems?
Some species have a value as a part of the way of life in a country or region, like the kangaroo in Australia. These animals are protected by not only the government, but by patriotic people.
How is economics a reason to protect ecosystems?
Some species have a financial value. e.g. tourists who like to see untouched natural landscapes, and medicinal drugs found in plants.
How is survival a reason to protect ecosystems?
We get our oxygen, water, and food from the environment around us, so in order to survive, we need to preserve the ecosystems.
How is compassion a reason to protect ecosystems?
Humans feel sympathy for other organisms. Compassion refers to the idea that every organism has a right to live and humans have no right to exterminate them.
How have eucalypts adapted to survive and benefit from fires?
-oil in their leaves that catch fire easily
-stringy bark that hangs off the tree and catches fire easily
-thick bark that insulates growing parts of tree
-have epicormic growth which gives them a competitive advantage other over species that take time to rejuvenate after a fire
-some eucalypt species have lignotubes that are swollen stems underground that quickly sprout out after a fire.
What happens to the animals during a fire?
Animals migrate or burrow. Animals too slow to do these die. Afterwards the dead are replaced by the surrounding populations that come because of the healthy sprouts that are good for the herbivores.
a period of no rain or low rainfall.
What are the disadvantages of a drought?
-increased death rate
-loss of plant cover leads to soil erosion by wind.
-when rainfall does come, water erosion will damage the land by washing away the soil.
Why would a drought increase the death rate?
Plants die due to a lack of water. This removes food, shelter, and nesting sites from animals, making them die or migrate.
Heavy rains where rivers overflow their banks to cover normally dry areas of land.
What are the advantages of a flood?
-In dry places there is an explosion of life where animals and plants reproduce due to the extra food and favourable living conditions.
-pelicans fly in to nest
What are the disadvantages to a flood?
-animals drown from lack of oxygen to breathe.
-plants drown from lack of oxygen at their roots.
Define habitat destruction.
Damage done to the environmental factors that an organism depends on for survival.
What are some examples that cause habitat destruction?
Land clearing, mining, and logging.
Define introduced species.
Animals and plants brought to a place from another country that are not native.
Define feral animals.
Introduced species that have become established in the wild.
What do feral animals do?
Feral cats and foxes kill native animals and many others such as rabbits, cats, and rats compete with native animals for food and shelter.
Chemicals that kill insects.
Define cumulative poisoning.
When poisoning accumulates over time. E.g. DDT was absorbed by plants and animals and the predators who ate those received more poisoning (because they eat more) and so on.
What is an alternative to insecticides?
Biological control. When you breed natural enemies to ward off and kill pest species. e.g. wasps and aphids.
Define chemical pollution.
Chemicals escaping into the environment that can damage ecosystems.
Provide examples of chemical pollution.
-microbeads and microfibers enter bodies of low order consumers and absorb heavy metals and toxic substances.
-large pieces of plastic being swallowed by seabirds.
-marine animals getting stuck in plastic lines and drowning.
Killing more animals than can be replaced by normal breeding cycles.