All the populations of organisms living close enough together for potential interaction make up a(n) _____.
lowers the carrying capacity of both competing populations
In general, interspecific competition _____.
The predator eats (a benefit), and the prey gets eaten (a harm). (+…-)
The ecological relationship between termites and the wood-digesting protozoans that live in their gut is an example of _____.
what it eats
An organism’s “trophic level” refers to _____.
Secondary and tertiary consumers
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 _____.
changes gradually because each species responds differently to changes in environmental factors
During ecological succession, the species composition of a plant community _____.
The energy for nearly every organism in almost every ecosystem ultimately comes from _____.
What generally flows in one direction through an ecosystem, from producers up through each level of consumers, and is not recycled?
a tropical coral reef
Which ecosystem would probably have the highest primary productivity?
nutrients and other life-sustaining molecules are in limited supply and must be continually recycled
Biogeochemical cycles are crucial to ecosystem function because _____.
An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.
the burning of larger amounts of wood and fossil fuels
The main cause of the recent increase in the amount of carbon dioxide in Earth’s atmosphere is _____.
1,000 times higher than
Current rates of extinction may be _____ those of the past 100,000 years.
the accidental introduction of the brown tree snake, a non-native predator
The primary cause of the extinction of native bird species in Guam was _____.
The single greatest current threat to biodiversity is _____.
sulfur … nitrogen oxides
Pollutants that are released into the atmosphere and form acid precipitation are _____ and _____.
Increasing concentrations of _____ such as methane, nitrous oxide, and carbon dioxide in the atmosphere are changing global climatic patterns.
is composed of interacting ecosystems
An ecological landscape _____.
may require conditions found in both of the bordering ecosystems
Edge-adapted species _____.
Connections between habitat fragments are referred to as _____.
regions with the potential for high levels of extinction
Biodiversity hot spots are _____.
A new and expanding field that uses ecological principles to develop methods to restore degraded areas to their natural state is called _____.