Functioning Ecosystems

Question 1

Productivity

Answer 1

amount of energy fixed in organic compounds measured by increase of biomass per unit of time

Question 2

biomass

Answer 2

amount of organic matter in a system

Question 3

photosynthetic efficiency

Answer 3

the fraction of light enrergy that plants and algae convert into chemical energy during photosynthesis

Question 4

gross primary production

Answer 4

the total amount of organic matter in an ecosystem produced as a result of photosynthesis

Question 5

net primary production

Answer 5

the amount of energy available for the herbivore to gain from consuming the producer after heat and waste loss

Question 6

reservoir pool

Answer 6

large abiotic component of a biogeochemical cycle in which matter is slowly exchanged with organisms - e.g. carbon in fossils or deep-sea sediments

Question 7

cycling pool

Answer 7

small compartment of a biogeochemical cycle with active exchange of matter between organisms

Question 8

Water Cycle starting from reservoir pools

Answer 8

1. Solar energy powers evaporation of water from oceans and to a minor extent, freshwater environments such as leaves through transpiration
2. This vapour is carried by air currents into the atmosphere
3. When it meets cool air the water vapour condensates and forms clouds of liquid water droplets or ice.
4. When the volume of water in clouds reaches a critical amount it falls to the ground as precipitation - snow or ice.
5. Most rain falls back to oceans however that which falls on land is ran-off towards the coasts or absorbed by soil which is eventually transpired back to the atmosphere.

Question 9

Carbon Reservoir pools

Answer 9

Trees, oil and coal

Question 10

Carbon cycling pools

Answer 10

1. Photsynthesis utilises atmospheric carbon dioxide which is rereleased into the atmosphere through cellular respiration
2. some amounts of carbon are a part of food chains where they are transfereed in biological molecules
3. Excretion - urine and feces
4. dead organisms

Question 11

What is nitrogen fixation

Answer 11

the conversion of atmospheric nitrogen N2 to NH3

Question 12

how is free nitorogen gas in soil transformed to nitrate

Answer 12

bacteria do Ammonnification

Question 13

nitrifying bacteria function

Answer 13

convert ammonia NH3 from decomposing organisms to NO2 and NO2 to NO3

Question 14

denitrifying bacteria function

Answer 14

liberate O2 by converting nitrate to nitrite to atmospheric nitrogen

Question 15

keystone species and its features

Answer 15

a species that has a large effect on its environment disproportionate to its abundance by maintaing biodiversity
influential on other organisms
able to eat a variety of organisms allowing to keep control of all populations
many negatiev effects would arise if removed from the ecosystem

Question 16

kesystone species example

Answer 16

flying fox - mutualist - disperses seeds across the ecosystem helping spread plant and tree species and aid in reproduction which in turn benefit other animals in the ecosytem