Ch. 2: Terrestrial Ecosystems and their Relationship to Cultivated Plants

Question 1

ecosystem

Answer 1

consists of a community of organisms in a physical environment, anywhere an organism my exist

Question 2

competition

Answer 2

occurs when plants of the same or different species attempt to use a resource in limited supply

Question 3

exclusion

Answer 3

when one needs resources, but none remain

Question 4

crop ecosystem

Answer 4

only have one or few species without exploiting all of the resources in the environment

Question 5

niche

Answer 5

exists when a resource is partitioned so that different portions of it are accessible only to certain species

Question 6

herbivore

Answer 6

animal/organism that only consumes plants

ex. mollusks, anthropods, mammals, and birds

Question 7

symbiotic associations

Answer 7

involves a permanent and close relationship/association between two organisms

Question 8

mycorrhizae

Answer 8

the association (usually symbiotic) of fungi with the roots of some seed plants

Question 9

Rhizobium

Answer 9

genus of bacteria that live symbiotically in the roots of legumes and fix nitrogen that is used by plants

Question 10

paraiste

Answer 10

organisms that derive their nutrition by living in/on the tissues of other organisms; often causing disease (bacteria)

Question 11

saprophyte

Answer 11

digest dead plant and animal material below the surface; essential to survival of ecosystem because they recycle nutrients

Question 12

detritivore

Answer 12

earthworms, insects, etc.

Question 13

succession

Answer 13

change in plant communities over time

Question 14

biome

Answer 14

collection of ecosystems with similar climate, soil, and plant composition

Question 15

Net Primary Productivity

Answer 15

carbon fixed minus the amount consumed by the plant and returned to the atmosphere through respiration

Question 16

pioneer species

Answer 16

can survive under special conditions and tend to get displaced as the ecosystem develops

Question 17

climax community

Answer 17

the theoretical endpoint of succession

Question 18

alien species

Answer 18

invade natural ecosystems, when non-native plants are immune to local disease and take out the native plants of the ecosystem

Question 19

human footprint

Answer 19

area used x intensity of use

an estimate of the land area required by an individual, a geographic area, a sociopolitical group, or world population taken as a whole