Unit 4 Section 3- Energy Transfer, Farming Practises And Productivity Flashcards
What is the main route by which energy enters an ecosystem?
Photosynthesis
What are plant’s role in an ecosystem?
Plants concert energy into a form hat can be used by other organisms by photosynthesis, they are producers
What is the difference between food chains and food webs?
Food chain- simple line of energy transfer
Food web- shows all the food chains in an ecosystem and how they overlap
What happens to energy locked up in things that can’t be eaten?
Decomposers breakdown dead or undigested material and recycle it
How is energy lost?
Not all light can be used by the leaves- wrong wavelength
Some parts can’t be eaten
Some food is indigestible and lost as waste
Respiration for movement and body heat- respiratory losses
What is gross productivity?
Gross productivity is the percentage of energy taken in
What is net productivity?
Net productivity is the percentage of energy available to the next tropic level
Net productivity=gross productivity-respiratory losses
What are the units for net productivity?
Kjm-2y-1
Kilojoules per metre squared per year
What is a pyramid of number?
Number of organisms at each tropic level
Not always pyramid shaped: small number of large organisms
What is a pyramid of biomass?
Shows dry mass (biomass kgm-2) at each tropic level
Usually pyramid shaped
Why are pyramids of biomass not pyramid shaped when including plankton?
There is a small number of plankton gay a certain time but there is a large number over a period of time
What is a pyramid of energy?
Shows net productivity at each level in kjm-2y-1
Always pyramid shaped
What is an ecosystem?
And ecosystem includes all the organisms living in a particular area and all the abiotic conditions
