B2.4 Zonation and succession Flashcards
What is zonation?
Zonation refers to changes in community composition along an environmental gradient.
What factors cause zonation?
Elevation, latitude, tidal level, soil horizons, and distance from a water source.
How can zonation be measured?
Using transects to assess biotic and abiotic factors along an environmental gradient.
What tools can be used to analyze zonation data?
Data tables, figures, and kite graphs.
What is succession?
Succession is the gradual replacement of one community by another due to changes in biotic and abiotic factors over time.
How does succession occur?
One community alters environmental conditions, allowing new species to colonize and outcompete the previous community.
How long can succession take?
It may continue for hundreds of years; pollen records in peat provide evidence of long-term changes.
What is the key difference between zonation and succession?
Zonation is a spatial process, while succession is a temporal process.
What is a sere in succession?
A sere is a stage in the succession process, where a community modifies conditions for the next community.
How does succession lead to a climax community?
Each seral stage alters the environment until a stable climax community is established.
Give an example of succession.
Mosses initiate soil formation on bare rock, allowing larger plants to establish over time.
What is primary succession?
Primary succession occurs on newly formed substratum where there is no soil or pre-existing community.
What are examples of primary succession?
It can occur on volcanic rock (e.g., Surtsey), moraines from retreating glaciers, wind-blown sand, or water-borne silt.
What are the key stages of primary succession?
Pioneer species colonize first, followed by seral communities, leading to a climax community.
What is secondary succession?
Secondary succession occurs on bare soil where a pre-existing community has been removed, such as abandoned farmland or a forest after a fire.
What are examples of secondary succession?
The Broadbalk Wilderness at Rothamsted or a forest regrowing after a wildfire.
How do energy flow and productivity change during succession?
They increase as biomass accumulates and ecosystems develop greater complexity.
How do species diversity and soil depth change over time in succession?
They increase as more species establish, contributing to deeper and more nutrient-rich soil.
What factors influence an ecosystem’s ability to tolerate disturbances?
Biodiversity, resilience, and stability.
How does succession contribute to ecosystem resilience?
Increased diversity through succession enhances stability and resistance to disturbances.
How can human activity affect ecosystem resilience?
Human interference, such as deforestation or pollution, can reduce diversity and stability, making ecosystems more vulnerable to disturbances.
