Ecosystems Flashcards
What is an ecosystem?
An area where organisms present are affected by and interacts with biotic and abiotic factors
State the different examples of an ecosystem
Rock pools
Playing field
Large tree
State the biotic factors of a rock pool
producers are seaweeds which can be eaten by herbivores like limpets
There exists strong competition for food (e.g. seaweed)
This can decline the population or organisms present in small rock pool ecosystem
State the abiotic factors of a rock pool
High and low tides affect rock pools heavily.
During high tide these pools become completely submerged by seawater.
Therefore, organisms experience some abiotic factors such as pH, salinity, temperature like that of marine organisms.
But during low tide, these organisms face more adverse abiotic conditions such as high salinity and temperatures .
These conditions are tolerable by organisms who have a wide range of tolerance.
State the biotic factors of a playing field
Grasses , daisies, clover and dandelions form the producer level.
Large number of animals (such as caterpillars and rabbits act as consumers
State the abiotic factors of a playing field
Excessive precipitation leads to very wet year - facillitates water logging of soil
Making it unsuitable of growth of plants
Due to less numbers of producers,decline in population of consumers takes place
State the biotic factors of a large tree
Leaves of a large tree can become food for caterpillars
Excessive consumption of tree leaves will lead to defoilation, slow growth and eventual death of the tree
State the abiotic factors affecting a large tree
Prolonged exposure to harsh environments such as drought has negative impact on the growth of a tree.
Due to these factors, death of plant parts or death of whole tree may occur
What is biomass?
Mass of a living organism
How is biomass used?
Energy is stored in the form of biomass and it is transferred through the ecosystem between trophic levels
What does the transfer of energy show?
The transfer of biomass
How does the transfer of biomass/energy occur?
Transfer of biomass occurs due to presence of food chain and food web
Define what is meant by a food chain
Simple linear chain of different trophic levels where organism of one trophic level eats organism of another trophic level
Define what is meant by a food web
network of multiple food chains.
Due to this network, now it is no more simple and linear, rather it has become complex and web-like
between what type of trophic level does the transfer of biomass take place?
From producers to consumers
What cannot be transferred further in the food chain?
All the energy transferred to next trophic level from previous trophic level cannot be transferred further
Give examples of how energy is lost?
In the process of respiration and other metabolic activities
Define Gross Productivity
The absorbed energy at a certain trophic level
Define Net Productivity
The actual energy available for next trophic level
How do you calculate net productivity?
Gross productivity - Respiratory loss
How do you calculate efficient energy transfer
(Net productivity/ energy recieved) * 100
Outline the energy transfer between trophic levels can be measured by following steps
1) Calculation of amount of biomass seperately in both trophic levels
2) Multiplication of size of population with amount of biomass in both trophic levels
3) This provides total amount of energy in the organisms at that trophic level
4) Difference between the amount of energy from both trophic level will be the amount of energy transferred
Outline the human activities that can manipulate the transfer of biomass through ecosystems
Herbicides Fungicides Insecticides Intro of natural predators Fertilisers Livestock
How do herbicides manipulate the transfer of biomass
Use of herbicides to kill weeds for reducing competitiion with agricultural crops for sunlight leads to faster growth, larger size and increased productivity
