Ch. 2: Terrestrial Ecosystems and their Relationship to Cultivated Plants Flashcards
ecosystem
consists of a community of organisms in a physical environment, anywhere an organism my exist
competition
occurs when plants of the same or different species attempt to use a resource in limited supply
exclusion
when one needs resources, but none remain
crop ecosystem
only have one or few species without exploiting all of the resources in the environment
niche
exists when a resource is partitioned so that different portions of it are accessible only to certain species
herbivore
animal/organism that only consumes plants
ex. mollusks, anthropods, mammals, and birds
symbiotic associations
involves a permanent and close relationship/association between two organisms
mycorrhizae
the association (usually symbiotic) of fungi with the roots of some seed plants
Rhizobium
genus of bacteria that live symbiotically in the roots of legumes and fix nitrogen that is used by plants
paraiste
organisms that derive their nutrition by living in/on the tissues of other organisms; often causing disease (bacteria)
saprophyte
digest dead plant and animal material below the surface; essential to survival of ecosystem because they recycle nutrients
detritivore
earthworms, insects, etc.
succession
change in plant communities over time
biome
collection of ecosystems with similar climate, soil, and plant composition
Net Primary Productivity
carbon fixed minus the amount consumed by the plant and returned to the atmosphere through respiration
pioneer species
can survive under special conditions and tend to get displaced as the ecosystem develops
climax community
the theoretical endpoint of succession
alien species
invade natural ecosystems, when non-native plants are immune to local disease and take out the native plants of the ecosystem
human footprint
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
