Answer:
limiting factor
Explanation:
In an ecosystem, certain factors hinder the growth or abundance of the population of organisms. These factors are called LIMITING FACTORS. Limiting factors, which can be biotic, food, drought, predation, disease etc, are factors that inhibits a population of organism from becoming enlarged. There are two types of limiting factors viz: density dependent (depends on size) and density independent (not dependent on size).
This is the case of a drought that dries up the stream that inhabits a population of salamanders. The drought causes the unavailability of water, which will ultimately have an effect on the growth of the salamander population. Hence, the DROUGHT is considered a LIMITING FACTOR.
