principles of ecology - powerpoint 1

Questions and Answers

Which statement best reflects modern ecological thinking about ecosystems?

Ecological interactions are complex and can lead to different communities forming under similar conditions. (correct)

Ecosystems consistently revert back to their original state after disturbances.

Stable ecosystems exist that are completely unaffected by random perturbations.

All ecosystems maintain a perfect balance at all times.

How does the Gaia hypothesis describe ecosystems?

As self-perpetuating systems that maintain life conditions indefinitely. (correct)

As systems that do not require external inputs for stability.

As non-physical systems that rely on species extinction for balance.

As interconnected systems that are entirely self-regulating.

What aspect of ecological studies emphasizes the importance of different levels of organization?

All ecological relationships are considered at a single level of organization.

Ecologists limit their studies to only abiotic components of ecosystems.

Ecology focuses solely on individual species rather than communities.

Ecologists select appropriate spatial and temporal scales to study interactions. (correct)

What is meant by the term 'ecosystem' in ecological studies?

A community of organisms along with their physical environment. Signup and view all the answers

Which of the following best describes the concept of 'scale' in ecological research?

It encompasses spatial and temporal dimensions important for ecological interactions. Signup and view all the answers

What role do random perturbations play in ecological systems as per modern understanding?

They are crucial in shaping ecological dynamics and community formation. Signup and view all the answers

Which statement regarding the 'balance of nature' is accurate based on modern ecological perspectives?

The balance of nature is a myth as ecosystems are always in flux. Signup and view all the answers

What is the biosphere defined as in ecological terminology?

All the living organisms on Earth and the environments they inhabit. Signup and view all the answers

How do contemporary ecologists approach questions regarding ecological interactions?

By considering both biotic and abiotic components and their interconnections. Signup and view all the answers

Which of the following would NOT be considered a spatial scale in ecological research?

Understanding historical changes in species identity over geologic time. Signup and view all the answers

What characteristic of amphibians makes them useful as biological indicators of environmental health?

Their skin is permeable, allowing pollutant molecules to pass through. Signup and view all the answers

In Pieter Johnson's research, what was the role of the aquatic snail, Helisoma tenuis?

It served as an intermediate host for Ribeiroia parasites. Signup and view all the answers

What was observed when the number of Ribeiroia parasites increased in the controlled experiments?

Fewer tadpoles survived and more had deformities. Signup and view all the answers

What result was found in Kiesecker's field experiment regarding pesticide contamination?

Pesticides reduced the ability of frogs to resist parasite infections. Signup and view all the answers

Which experimental design method was employed by Johnson et al. to assess the impacts of Ribeiroia parasites?

Controlled experiment with various treatment levels. Signup and view all the answers

What is the significance of the statement 'the balance of nature' in relation to ecosystems?

It implies ecosystems are stable and in a state of balance. Signup and view all the answers

Why do amphibians lay eggs without a protective shell?

To facilitate respiration and nutrient absorption. Signup and view all the answers

What was a direct consequence of mimicking Ribeiroia cysts in tadpoles during experiments?

Deformities were produced in tadpoles. Signup and view all the answers

Which of the following factors might also be important in the decline of amphibian populations, aside from Ribeiroia?

Climate change and habitat loss. Signup and view all the answers

What potential effect do small glass beads have when implanted in tadpoles in experiments?

They mimic Ribeiroia cysts causing deformities. Signup and view all the answers

What is the primary focus of ecology?

The interaction of organisms with each other and their environment Signup and view all the answers

Which ecosystem service is valued at over $0.5 billion per year?

Plant and pollinator networks in food production Signup and view all the answers

How does modern ecology conceptualize ecosystems?

As complex systems similar to financial networks Signup and view all the answers

What role do natural predators play in agriculture?

They reduce pesticide use significantly worldwide Signup and view all the answers

What is one implication of studying cooperation in ecosystems?

Understanding of economic systems can improve Signup and view all the answers

How are algae and plankton vital to global processes?

They regulate global oxygen dynamics Signup and view all the answers

Which of the following does NOT directly relate to ecological principles?

Studying financial market trends Signup and view all the answers

What is one way E.coli contributes to human health?

It produces vitamin K essential for survival Signup and view all the answers

What can be inferred about amphibian populations based on the given information?

There is a correlation between deformities and population decline Signup and view all the answers

What principle of ecology helps understand unexpected results in ecosystems?

Long chains of cause-and-effect Signup and view all the answers

Study Notes

Introduction to Ecology

Definition: Study of interactions between organisms and their environment.
Key areas of focus: Scale, organization, and interactions.

Importance of Ecology

Ecological networks: Plants and pollinators contribute over $0.5 billion annually to food production.
Marine ecosystems: Coral reefs crucial for food and tourism, impacting billions globally.
Human health: E.coli in the gut produces essential vitamin K.
Pest control: Natural predators have led to a 50% reduction in global pesticide usage.
Indoor environments: Humans spend 90% of time indoors, interacting with diverse microbial ecosystems.

Ecological Systems and Their Complexity

Modern ecology views ecosystems as complex systems, interconnected with disciplines like finance and robotics.
Cause-and-effect relationships can lead to non-intuitive ecological results, as shown by increased flower presence around fish-occupied ponds.

Case Study: Amphibian Deformity and Decline

High deformity rates in amphibians indicate environmental problems; they are "biological indicators."
Observation of Pacific tree frogs linked deformities to the parasite Ribeiroia ondatrae, transmitted through aquatic snails.
Controlled experimental studies demonstrated a decrease in tadpole survival and increased deformities with higher parasite exposure.
Field studies examined the effect of pesticides on amphibian susceptibility to parasites, revealing complex interactions.

Modern Ecological Thinking

The notion of "balance of nature" has evolved; ecosystems are not inherently stable and can undergo significant changes.
Random disturbances can cause various ecological communities to emerge under the same environmental conditions.

Scale and Organization in Ecology

Ecologists study systems at varying scales:
- Spatial scales: Small (soil microorganisms) to large (atmospheric pollutants).
- Temporal scales: Short-term (plant responses) to long-term (species evolution).
Levels of organization:
- Population: Individuals of the same species in a specific area.
- Community: Assortment of various species interacting in an area.
- Ecosystem: Communities of organisms and their physical environments.
- Landscapes and biosphere encompass broader ecological contexts.

Answering Ecological Questions

Ecologists utilize observational data, experiments, and mathematical modeling to evaluate hypotheses about natural systems.

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Description

Explore the foundational concepts of ecology in PCB 4043. This quiz covers scales, organization, and the intricate interactions that define ecosystems. Delve into the significance of food networks, air dynamics, and fisheries in sustaining economies.