Ecological Succession Flashcards
7 cards from real Ecology practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ecological Succession flashcards as text
The inhibition model of succession proposes that:
Answer: Early species resist replacement by later species until they die or are disturbed
The inhibition model suggests that early colonizers can inhibit the establishment of later species, so succession only advances when early species are removed by disturbance or die naturally.
What is the primary source of nitrogen input during early primary succession on bare rock?
Answer: Nitrogen fixation by cyanobacteria and lichens
Early colonizers such as cyanobacteria and certain lichens fix atmospheric nitrogen, making it available to the ecosystem and contributing to soil development during primary succession.
Which term describes the idea that multiple stable states can exist in an ecosystem, and a disturbance can shift the system from one state to another?
Answer: Alternative stable states
The alternative stable states concept holds that ecosystems can exist in more than one stable configuration, and large disturbances can push a system across a threshold into a different stable state.
How does species richness typically change during early to mid-stages of succession?
Answer: It generally increases as new species colonize and habitat becomes more complex
Species richness typically increases during early to mid-succession as habitat complexity grows, resources diversify, and more species can find suitable niches.
Which of the following best describes the tolerance model of succession?
Answer: Later species can establish regardless of early species but are eventually out-competed by better competitors
The tolerance model proposes that later successional species can establish early but grow slowly; they eventually replace early species because they are better competitors for resources as conditions mature.
What role do mycorrhizal fungi play in ecosystem succession?
Answer: They facilitate plant establishment by enhancing nutrient uptake, speeding succession
Mycorrhizal fungi form mutualistic associations with plant roots, improving nutrient and water absorption, which helps plants establish and grow faster, thereby facilitating successional progression.
The Intermediate Disturbance Hypothesis predicts that species diversity is highest when:
Answer: Disturbance occurs at intermediate levels
The Intermediate Disturbance Hypothesis predicts peak species diversity at intermediate disturbance levels because disturbance prevents competitive exclusion while still allowing many species to persist.