Ecosystems Flashcards
What are ecosystems?
An ecosystem is a community of living organisms (biotic) in conjunction with the nonliving (abiotic) components of their environment interacting as a system.
What are biotic and abiotic factors?
Biotic Factors: The living things in an ecosystem are called biotic factors. Living things include plants, animals, bacteria, microbes, fungi, etc.
Abiotic Factors: The non-living parts of an ecosystem are called abiotic factors. In an ecosystem some abiotic factors are
–sunlight, –temperature –atmospheric gases –water –weather – wind, rain, etc. –pH –rocks –Soil - minerals , salts, clay, water, sand particles etc.
What is the difference between natural and artificial ecosystems?
Natural Ecosystems:
Consists of many species of plants and animals.
Genetic diversity is very high.
The sunlight is the energy source for plants and this energy drives all biological cycles.
Food chains are long and complex
Natural nutrient cycling ensures maximum and efficient cycling of nutrients.
Artificial Ecosystems:
Consists of one major crop plant (monoculture).
Genetic diversity is very low - other plant species are removed.
The sunlight is an energy source but artificial fertilizers and other nutrients are externally supplied to the soil.
Food chains are simple
Incomplete nutrient cycling. Harvesting of the crops removes large amount of nutrients from the soil making the soil less fertile each time.
What environmental organisations are there?
Environmental Organisation -
Biosphere, Ecosystem, Community, Population, Organism.
Each ecosystem can be divided into…
Habitat: The non-living part (abiotic).
Community: The living part (biotic)
Each community is made up of many different populations.
A population is all the members of a particular species living in one habitat.
What are the 4 top tropic levels in the ecosystem?
4 Tropic (Feeding) Levels in the ecosystem?
Producer
Primary Consumer
Secondary Consumer
Tertiary consumer
Define Decomposer: An organism that feeds on dead organisms or waste products and breaks them down to supply plants with the necessary nutrients. All organisms produce will eventually die and be broken down by decomposers.
Producer: Makes its own food using energy from the sun.
Consumer: An organism that has to eat other organisms to survive. They can’t make their own food.
Explain what plants use photosynthesis for?
Most of the sunlight that falls on leaves is not absorbed and used.
What happens?
Most doesn’t hit the plants
Some is reflected from the leaf’s surface
Some passes straight through the leaf without hitting chloroplasts
Only part of the light is useful and can be absorbed by chlorophyll
The plant uses this energy to grow and produce new leaves
The plants use the energy they do gain to grow, move around and produce new cells, majority of the energy is actually lost.
The sun is an abiotic factor which supplies producers with the solar energy in need to produce food (glucose).
Without solar energy, ecosystems would fall apart. Removal of the sun would cause a domino effect.
What does an energy pyramid show and what is the 10% rule?
Amount of available energy decreases for higher consumers (those down the food chain).
It takes a large number of producers to support a small number of primary consumers.
It takes a large number of primary consumers to support a small number of secondary consumers.
The 10% Rule – The amount of available energy at each trophic level decreases as it moves through an ecosystem. 10% of the energy at any level is transferred up to the next level.
Biomass: Shows more accurate indications of energy.
It shows the mass (kg) of each animal and how much that animal gains from the one below or above.
Number: Represents the number of organisms that make up each trophic level
What are autotrophs?
Autotrophs
An autotroph is any organism that can produce its own food supply. Autotrophs are also called producers.
Example plants, algae, bacteria and some protists.
Producers
Producers use cellular respiration to supply the energy they need to live.
Producers use most of the energy they make for themselves, but do store some energy.
The energy that is not used by producers can be passed onto organism that cannot make their own energy (consumers).
The sun is an abiotic factor which supplies producers with the solar energy in need to produce food (glucose).
What are the different orders to consumers?
Consumers can be grouped into different types:
Herbivores these consumers eat producers.
Carnivores only eat other consumers.
Omnivores eat producers and consumers, they eat meat and plants.
First order consumer
Consumers that eat producers to get energy.
Are first or primary consumers.
Are herbivores.
Second order consumer
A consumer that eats another consumers energy.
They are called secondary or second order consumers.
They can be a carnivore or omnivore.
They may be predator or scavengers.
Third order consumer
A consumer that eats a consumer that already ate a consumer.
They are called tertiary or third order consumers.
They can be a carnivore or omnivore.
They may be predators or scavenger.
What are types of consumers and give an example of a food web?
Omnivore: A consumer that eats both producers and consumers.
Herbivores: A consumer that only eats producers.
Carnivores: A consumer that only eats other consumers.
Scavengers: Consumers that eat other dead consumers.
Decomposers: An organism that primarily feeds on dead organisms or the waste from living organisms (consumers and decomposers) and break them down into their nutrient components so that plants can use them to make more food.
Sun (Energy) —-> Producer (Grass) —–> Primary consumer (Grasshopper) —–> Secondary consumer (Rat) —–> Tertiary consumer (Owl).
What is carrying capacity?
An environment can only support as many organisms as there is available food, water and free space.
Carrying capacity = maximum number of organisms that can live somewhere based on food, water and free space.
Every species has a different carrying capacity.
Food, water and free space are the limiting factors that determine carrying capacity.
The number of people, animals, or crops which a region can support without environment degradation.
When a population is below carrying capacity, it will increase in size. Whereas if a population is above carrying capacity the numbers are going to decrease in size.
What does population dynamics mean?
Factors affecting population dynamics:
Births – Movement into the system.
Deaths – Movement out of the system.
Immigration – Movement into the system.
Emigration – Movement out of the system.
What kinds of population growth is there?
Exponential Population growth:
The population grows indefinitely.
Only occurs when there is no limit on resources.
Logistic Population Growth:
More realistic.
Population growth strives for dynamic equilibrium (balance).
Population rises, not enough resources, population begins to decrease.
What are feedback loops?
Predator Prey Cycles -
The predators population pattern is mimicking the preys population pattern because it is reliant on the prey for food.
Feedback Loops -
This cycle of population increase and decrease among predators and prey is known as feedback loop.
These loops in nature can either represent the stabilising of a population or the spikes in growth or death in a population.
How does energy flow in an ecosystem?
If a 180kg lion needs to eat half its body weight in a week to survive, and an antelope weighs 45kg, how many antelopes must a lion eat in a week to survive?
Needs to eat 90kg worth so 2 antelopes.
A small mouse must eat its body weight (500g) in wild berries each day to survive. If an average wild berry weighs 4g, how many berries does the mouse need to consume?
125 berries
Assume an owl must eat 8 mice per day, while a wolf must eat 2 owls per day. Use this information along with your answer from Question #2 to calculate how many berries are needed to keep a wolf alive for a day?
8 x 125 x 2 = 2000 berries
