Ecology: Disturbance and Succession

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Questions and Answers

What does it mean if a community shows resilience?

The community can quickly restore itself after a disturbance. (correct)

The community avoids disturbances completely.

The community can withstand disturbance without any changes.

The community is permanently altered after a disturbance.

Which of the following best describes resistance in an ecosystem?

The ability of an ecosystem to recover after extreme changes.

The ability to avoid disturbances entirely. (correct)

The method of gradually replacing species over time.

The capacity to adapt to any environmental condition.

What are small-scale disturbances often referred to as?

Catastrophic disturbances

Systemic disturbances

Gap-phase disturbances (correct)

Macro-disturbances

In the context of forest ecology, which species is mentioned as being resilient to ecological collapse?

Jack pine trees Signup and view all the answers

What occurs as a result of microsuccession in a community?

Restoration of the community in gaps created. Signup and view all the answers

When intense disturbance in an ecosystem occurs, what is the likely outcome?

Extreme community changes. Signup and view all the answers

What is the relationship between ecological succession and community restoration?

Succession plays a role in restoring the original community. Signup and view all the answers

How does fire influence community structure and function in ecosystems?

It can create habitats for certain species to thrive. Signup and view all the answers

Which adaptations allow certain oak trees to survive prescribed burns?

Thick bark Signup and view all the answers

How did fire suppression affect the blue lupine population?

Led to their rare occurrence and butterfly extinction Signup and view all the answers

What is the term for the community-level recovery following a disturbance?

Succession Signup and view all the answers

What does it mean if an ecosystem shows resilience?

It can quickly recover to its original state Signup and view all the answers

Which of the following species is noted for its dependence on dead wood from prescribed burns?

Red-headed Woodpecker Signup and view all the answers

What is most likely a consequence of disturbance in an ecosystem?

Destruction of certain community parts Signup and view all the answers

Which of the following terms describes an ecosystem's ability to resist disturbances?

Resistance Signup and view all the answers

Which conservation strategy involves reintroducing species to areas that have recently experienced disturbances?

Species reintroduction Signup and view all the answers

What term refers to disturbances that affect an entire community?

Stand-replacing disturbances Signup and view all the answers

Which of the following is NOT considered a large-scale disturbance?

Small rodent activity Signup and view all the answers

How do pioneer trees differ from shade-tolerant trees in ecological succession?

Pioneer trees grow quickly and are shade-intolerant Signup and view all the answers

Which type of ecological succession occurs on bare rock?

Lithosere Signup and view all the answers

Who argued that there is no predictable end-point to ecological succession?

Henry Gleason Signup and view all the answers

What does the term 'seral stages' refer to?

Stages of community development after a disturbance Signup and view all the answers

Which of the following communities is characterized by species co-adapted to fire?

Coniferous forests Signup and view all the answers

What is the primary characteristic of psammoseres?

Succession on sandy substrates Signup and view all the answers

Which factor contributes to the unpredictability of fire frequency in ecosystems?

Wind speed and direction Signup and view all the answers

In ecological terms, what does a climax community represent?

A stable community at the end of succession Signup and view all the answers

What is a potential outcome of frequent disturbances in an ecosystem?

Decreased species diversity Signup and view all the answers

During a hydrosere, what occurs as the lake sediment accumulates over time?

The lake may eventually become a forest Signup and view all the answers

Which ecological strategy is characterized by rapid growth and high reproductive rates?

R-strategist strategy Signup and view all the answers

What role do biological agents play in ecological disturbances?

They can cause large-scale changes to community structure. Signup and view all the answers

Study Notes

Disturbance and Succession

Disturbance: Event that causes damage to a community or ecosystem.
Succession: The recovery process following a disturbance.
Frequency of Disturbance: Can be regular (tides, seasons), or unpredictable (wildfires, volcanic eruptions).
Small-Scale Disturbances: Often occur within an otherwise intact community.
- Examples: Death of a single tree, fallen tree, prescribed burns.
- Micro-succession: The recovery of a community in the gap created by a small-scale disturbance.

Resilience and Resistance

Resilience: The ability of a system to recover to its original state after a disturbance (e.g., Jack pine forests after fire).
Resistance: The ability of a system to avoid disturbance or minimize its impact (e.g., hardwood forests that withstand treefalls).

Large-Scale Disturbances

Affect entire communities.
Stand-replacing disturbances: Change the entire community structure.
- Examples: Wildfires, windstorms, glaciation, biological agents.
- Many organisms have adaptations specific to these frequent disturbances, such as oak trees resistant to fire.

Climax Communities

Frederick Clements: Suggested that successions have a predictable end-point, with a stable climax community that remains relatively unchanging.
Henry Gleason: Argued that there is no predictable end-point, and that climax communities are not necessarily co-evolved.
Modern view: Older ecosystems can remain stable over long periods, representing a kind of climax community. The concept remains useful though.

Seral Stages

The sequence of community types during the recovery process is known as seral stages.
Seres: Represent the overall view of how an ecosystem changes over time.

Examples of Seres

Hydrosere: Succession in a young lake or pond. Starts oligotrophic (low nutrients), eventually accumulating sediment, increasing nutrients, and potentially becoming a wetland or forest.
Lithosere: Succession on bare rock. Begins with algae, lichens, and mosses, followed by grasses and shrubs.
Psammosere: Succession on sandy substrates. Moving substrates pose a challenge for plants, leading to greater reliance on vegetative reproduction.

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Description

Explore the concepts of disturbance and succession in ecosystems through this quiz. It covers the impact of both small and large-scale disturbances, the roles of resilience and resistance, as well as the recovery processes following ecological disruptions. Test your understanding of how communities respond to environmental changes.