According to the principle of competitive exclusion, two species cannot continue to occupy the same _____.
In terms of + (this member of a species pair benefits from the interaction), - (this member of a species pair is harmed by the interaction), and 0 (this member of a species pair is unaffected by the interaction), predation can be described as a _____ relationship.
The ecological relationship between termites and the wood-digesting protozoans that live in their gut is an example of _____.
During ecological succession, the species composition of a plant community _____.
changes gradually because each species responds differently to changes in environmental factors
Consider this segment of a food web: Snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; owls eat shrews. The shrew occupies the trophic level(s) of _____.
secondary and tertiary consumers
What generally flows in one direction through an ecosystem, from producers up through each level of consumers, and is not recycled?
Which of the following ecosystems would probably have the highest primary productivity? Assume that we are comparing similar sizes of each ecosystem.
a tropical coral reef
Biogeochemical cycles are crucial to ecosystem function because _____.
nutrients and other life-sustaining molecules are in limited supply and must be continually recycled
An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.
The main cause of the recent increase in the amount of carbon dioxide in Earth's atmosphere is _____.
the burning of larger amounts of wood and fossil fuels
when populations of two different species compete for the same limited resource
consists of all organisms in a community and the abiotic environment and the organisms interact