Ecology Community Characteristics and Succession

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Questions and Answers

What key concept influences the participation of diverse groups in ecology?

Historical scientific methods

Role models and sense of belonging (correct)

Access to higher education

Technological advancements

What are the two main components measured when assessing community diversity?

Ecosystem size and greenhouse gas levels

Species richness and species evenness (correct)

Biotic and abiotic factors

Population density and habitat range

Which of the following levels of ecological hierarchy examines interactions among different species?

Ecosystem

Community (correct)

Organism

Population

What is the primary source of energy for most ecosystems?

Solar energy Signup and view all the answers

How does Traditional Ecological Knowledge (TEK) complement Western science?

It provides insights from Indigenous cultures. Signup and view all the answers

What challenge is posed by environmental factors when studying biodiversity?

Communities are continuously evolving Signup and view all the answers

Which category of organisms are considered primary producers in ecosystems?

Autotrophs that capture solar energy Signup and view all the answers

What does the term 'biosphere' encompass in ecological studies?

All ecosystems and living organisms on Earth Signup and view all the answers

What was observed about young aspen trees in relation to elk populations?

Young aspen trees grew taller when elk populations fell below 4 elk per square kilometer. Signup and view all the answers

How did the presence of wolves relate to aspen recovery in the studied areas?

Wolves reduced elk numbers, allowing for better aspen recovery. Signup and view all the answers

What conclusions were drawn regarding human activity and its influence on elk behavior?

In Glen Creek, elk browsed less due to reduced human activity. Signup and view all the answers

Which of the following was a significant effect of decreased elk browsing on aspen trees?

Positive changes in plant communities were observed, aiding aspen recovery. Signup and view all the answers

In which area did young aspen trees show less evidence of being browsed?

Glen Creek, in areas with predator escape routes. Signup and view all the answers

What primary characteristic defines a community?

Species richness and evenness Signup and view all the answers

Which of the following is an example of primary succession?

Colonization of land after a volcanic eruption Signup and view all the answers

What term describes the first species to colonize a disturbed area?

Pioneer species Signup and view all the answers

Which best describes the Intermediate Disturbance Hypothesis?

Moderate disturbances enhance species diversity Signup and view all the answers

What usually changes during succession in an ecosystem?

Plant biomass and species diversity vary Signup and view all the answers

Which ecological disturbance is typically human-induced?

Deforestation Signup and view all the answers

What impact do fires have on certain species in California's wildlands?

Some species require fire to germinate Signup and view all the answers

What is a climax community?

A stable community that can be disrupted by disturbances Signup and view all the answers

What does the Competitive Exclusion Principle state?

Two species cannot coexist if they compete for the exact same resources. Signup and view all the answers

Which of the following is NOT a type of trophic interaction?

Mutualism Signup and view all the answers

What role do secondary consumers play in an ecosystem?

They feed on herbivores and other carnivores. Signup and view all the answers

Which adaptation is typically associated with prey species?

Camouflage and escape strategies Signup and view all the answers

How does ecology differ from environmental science?

Ecology examines biological interactions and ecosystems. Signup and view all the answers

In which type of symbiotic relationship does one species benefit while the other is unaffected?

Commensalism Signup and view all the answers

What effect did the reintroduction of gray wolves have on the elk population in Yellowstone?

Elk population and behavior demonstrated positive changes. Signup and view all the answers

What is the impact of niche partitioning on species coexistence?

It facilitates coexistence by enabling slight variations in resource use. Signup and view all the answers

Which of the following best describes detritivores?

Organisms that feed on dead organic matter. Signup and view all the answers

What is coevolution?

The reciprocal evolution of interacting species in response to each other. Signup and view all the answers

Which factor complicates measuring biodiversity according to the document?

Historical discrimination against minority communities. Signup and view all the answers

What was a significant factor influencing the behavior of elk when wolves were reintroduced?

Fear of predation leading to decreased browsing on aspen. Signup and view all the answers

Which of the following best describes parasitism?

The parasite benefits while the host is harmed but not immediately killed. Signup and view all the answers

What aspect of ecological study has evolved significantly from its historical context?

Incorporation of quantitative research and experimentation. Signup and view all the answers

Which of the following statements about environmentalism is true?

It is a political advocacy movement for environmental protection. Signup and view all the answers

What dual factors contribute to the recovery of young aspen trees in Yellowstone?

Elk density and elk behavior impact aspen recovery. Signup and view all the answers

Study Notes

Community Characteristics

Community definition: Characterized by species richness and evenness
Dominant species: Often named after prominent plant species, heavily influencing community structure

Ecological Disturbances

Definition: Any event disrupting ecological balance, impacting biotic and abiotic factors
Types: Periodic (hurricanes) or random (meteorites), or anthropogenic (human-caused)

Succession

Ecological succession: Process of community development over time, either primary (new land) or secondary (disturbed land)
Primary succession: Occurs on newly formed land, starting with pioneer species (e.g., grasses, mosses)
Secondary succession: Follows disturbances on existing land, starting with species from the seed bank (e.g., abandoned pastures, after fire)

Pioneer and Climax Communities

Pioneer species: First species to colonize disturbed areas, often short-lived and adapted to harsh conditions
Climax community: A stable community resulting from succession, but potentially disrupted by disturbances

Ecosystem Changes During Succession

Changes during succession: Productivity, biomass, nutrient distribution, and species diversity shift throughout stages
Early stages: Typically high productivity and low diversity
Late stages: Typically low productivity and high diversity

Intermediate Disturbance Hypothesis

Hypothesis: Moderate levels of disturbance can enhance species diversity, while too little or too much disturbance can reduce it

Adaptations to Disturbance

Many species adapted to periodic wildfires (e.g., requiring fire to germinate or resprout from seedbank)

Species Interactions

Competition: Interspecific (between species) and intraspecific (within species); impacting resource use
Ecological niche: Role and space a species occupies, including resource use and interactions
Competitive Exclusion Principle: Two species competing for the same resources cannot coexist

Types of Trophic Interactions

Predation: Predator consuming prey
Parasitism: Parasite consuming host parts without immediately killing it
Herbivory: Herbivores consume plants
Detritivory: Detritivores feed on dead organic material

Adaptations

Predator adaptations: Size, weaponry, sensory adaptations for locating prey
Prey adaptations: Camouflage, escape strategies, chemical defenses (aposematic coloration, mimicry)

Symbiosis

Commensalism: One species benefits, the other is unaffected
Mutualism: Both species benefit (trophic/resource exchange, defensive/protection, dispersive/pollination)
Parasitism: One species benefits at the expense of the other

Mutualism and Coevolution

Mutualistic relationships can lead to coevolution where interacting species evolve in response to each other

Key Points

Historical discrimination creates barriers in ecology for minority groups
Socioeconomic factors impact access to wilderness
Western science may conflict with non-Western views; requires inclusive approach
Traditional Ecological Knowledge (TEK) complements Western science
Measuring community diversity involves species richness and evenness

What is Ecology?

Definition: Study of complex interrelationships between organisms and environment
Importance: Understanding ecological issues (habitat destruction, need for sustainable practices) and human curiosity about nature

Levels of Ecological Hierarchy

Organism: Individual species interactions with the environment
Population: Same species interacting together
Community: Interactions among different species
Ecosystem: Interactions between organisms and physical environment
Landscape: Multiple ecosystems at regional scale
Biosphere: All ecosystems and living organisms

Energy in Ecosystems

Sun: The primary energy source for most ecosystems (except deep-sea hydrothermal vents)

Trophic Levels

Primary producers: Autotrophs (e.g., plants) capturing solar energy
Primary consumers: Herbivores consuming plants
Secondary/Tertiary consumers: Carnivores eating herbivores/other carnivores
Detritivores: Organisms feeding on dead organic matter

Trophic Interactions

Interactions form a complex food web illustrating relationships and energy flow

Ecology: Focuses on biological interactions and ecosystems
Environmental science: Integrates ecology with abiotic factors and policy
Environmentalism: A political advocacy movement protecting environments

Historical Context

Ecology's evolution: From observation and description of nature to quantitative research and experimental designs
Influences of naturalists (e.g., John Muir) on ecological thought

Conclusion

Ecology's importance for understanding the natural world and addressing environmental challenges
Need for blending scientific inquiry with advocacy and conservation

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Description

This quiz covers key concepts in ecology, focusing on community characteristics, ecological disturbances, and the processes of succession. Explore the definitions and dynamics of pioneer and climax communities as well as the impact of disturbances on ecosystems. Test your understanding of these fundamental ecological principles.