Chapters 5, 6 + 7 - Nutrient Cycles Flashcards
What are producers?
Photosynthetic organisms that manufacture organic substances using light energy, water and carbon dioxide.
What are consumers?
Organisms that obtain their energy by feeding on other organisms rather than using the energy of sunlight directly.
What are decomposers?
Microorganisms that break down organic compounds in dead material and waste products into carbon dioxide, water and simple inorganic ions.
What is a detritivore?
An animal which feeds on the pieces of partly broken down plant or animal tissue known as detritus. E.g. Earthworms and woodlice.
What is the equation for net production?
Gross production - respiratory losses
What is gross production?
The total quantity of energy that the plants in a community convert to organic matter.
What is the equation for energy transfer?
(Energy available after the transfer / energy available before the transfer) X 100
What is biomass?
The total dry mass of the plants and/or animals in a particular place. Measured in trams per square meter (g/m2).
What is energy flow measured in?
kJ/m2/year
What is an agricultural ecosystem?
Ecosystem based on domestic animals or crop plants.
What is productivity?
The rate at which something is produced.
What is gross productivity?
Rate at which plants assimilate chemical energy.
What is a pest?
An organism that competes with humans for food or space.
What is a pesticide?
A substance which is used to control pests.
What is biological control?
The use of a pest’s natural predators or parasites to limit its population.
What is integrated pest management?
Managing pests by combining the use of chemical pesticides and other methods of control.
What is the carbon cycle?
The way in which the element carbon circulates or cycles in an ecosystem.
What is the nitrogen cycle?
The way in which the element nitrogen circulates or cycles in an ecosystem.
What is nitrification?
The conversion of ammonium compounds to nitrites and nitrates, by oxidation, with nitrifying bacteria.
What is nitrogen fixation?
The incorporation of nitrogen gas in the atmosphere into organic nitrogen-containing compounds.
What is ammonification?
Saprophytic micro organisms break down organic, nitrogen-containing substances into ammonium compounds.
What is denitrification?
The conversion of nitrates to nitrogen gas by denitrifying bacteria - reduction and an anaerobic process.
What is a fertiliser?
A substance which adds mineral ions to the soil.
What is eutrophication?
The consequence of an increase in nutrients, especially nitrates and phosphates, in fresh water lakes and rivers. Often leads to a decrease in biodiversity.
