Ecosystems

Question 1

define ecosystem

Answer 1

• interrelationship between biotic and abiotic factors
• components: habitat, population, community

Question 2

define niche

Answer 2

• the role of each species in an ecosystem
• no two species occupy exactly the same niche in the same ecosystem

Question 3

define cyclic changes

Answer 3

• changes repeat themselves into a rhythm
• like the fluctuation of predator-prey populations

Question 4

define directional changes

Answer 4

• not cyclic
• go in one direction and last longer than the lifetime of organisms in that ecosystem like coastline erosion

Question 5

define unpredictable/erratic changes

Answer 5

• no rhythm and no constant direction like the effects of hurricanes

Question 6

define trophic level

Answer 6

the level at which an organism feeds in a food chain

Question 7

define biomass transfer

Answer 7

transfer of biomass between trophic levels

Question 8

define productivity

Answer 8

rate of production of new biomass by producers

Question 9

define net productivity

Answer 9

energy available to next trophic level

Question 10

define gross primary production

Answer 10

the rate at which plants convert light energy onto chemical energy through photosynthesis

Question 11

define succession

Answer 11

progressive change in a community of organism over time

Question 12

define climax community

Answer 12

the final stable community that exists after succession

Question 13

define deflected succession

Answer 13

when succession is stopped or interfered with, such as by grazing or when lawn in mowed

Question 14

define pioneer species

Answer 14

species that begins succession, after colonising an area

Question 15

define plagioclimax

Answer 15

the sub climax community

Question 16

define secondary succession

Answer 16

succession that takes place on previously colonised or disturbed habitat

Question 17

define climatic climax

Answer 17

the climax community for a particular climate