Lichens and Environmental Health
17 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What role do lichens play in soil formation?

  • They release substances that break down rocks. (correct)
  • They decompose organic matter, enriching soil.
  • They provide habitats for soil-dwelling organisms.
  • They help regulate soil temperature.
  • Which lichen species is known to thrive in polluted environments?

  • Cladonia rangiferina
  • Rhizocarpon geographicum
  • Peltigera canina
  • Lecanora conizaeoides (correct)
  • How are lichens involved in nutrient cycling?

  • They absorb nutrients directly from the atmosphere.
  • They release nitrogen into the soil. (correct)
  • They break down rocks to release essential minerals.
  • They compete with other plants for nutrients.
  • What does the presence of a diverse lichen community suggest about an ecosystem?

    <p>It is generally healthy and undisturbed. (A)</p> Signup and view all the answers

    Which of the following is NOT a role lichens play in an ecosystem?

    <p>Primary producers (B)</p> Signup and view all the answers

    How do lichens contribute to the survival of reindeer and caribou during winter?

    <p>They provide a crucial food source. (D)</p> Signup and view all the answers

    Which of these lichens is important in the study of symbiosis and stress tolerance?

    <p>Xanthoria parietina (B)</p> Signup and view all the answers

    Why are lichens valuable for studying the effects of climate change?

    <p>They are very sensitive to changes in environmental conditions. (B)</p> Signup and view all the answers

    Which type of mycorrhizae form a dense hyphal sheath around the roots of their host plants?

    <p>Arbutoid Mycorrhizae (A)</p> Signup and view all the answers

    Which of the following is an example of a plant that forms arbutoid mycorrhizal associations?

    <p>Arctostaphylos uva-ursi (B)</p> Signup and view all the answers

    What is the primary role of orchid mycorrhizal fungi in the development of orchids?

    <p>Facilitating seed germination and early development (A)</p> Signup and view all the answers

    Which of the following is NOT a benefit of using mycorrhizae in sustainable agriculture?

    <p>Increased susceptibility to soil-borne diseases (B)</p> Signup and view all the answers

    Which mycorrhizal association is particularly important for the establishment and growth of forest trees?

    <p>Ectomycorrhizae (A)</p> Signup and view all the answers

    Which of these fungi forms mycorrhizal associations with various orchid species, providing essential nutrients for their growth?

    <p>Rhizoctonia spp. (D)</p> Signup and view all the answers

    Which of these mycorrhizal associations are similar to ectomycorrhizae, but specifically associated with certain families like Ericaceae?

    <p>Arbutoid Mycorrhizae (D)</p> Signup and view all the answers

    What is the primary role of pelotons in orchid mycorrhizae?

    <p>Facilitating nutrient exchange between the fungus and the orchid (D)</p> Signup and view all the answers

    Which of these is an example of how mycorrhizae are used in horticulture?

    <p>Applying mycorrhizal inoculants to nursery-grown ornamental plants like roses (B)</p> Signup and view all the answers

    Study Notes

    Lichens: Ecological Importance and Indicators of Environmental Health

    • Soil Formation and Stabilization: Lichens are pioneer organisms, initiating soil formation by breaking down rock surfaces with secreted acids. Examples include Rhizocarpon geographicum in alpine and arctic regions.
    • Nutrient Cycling: Lichens fix nitrogen (some species) and decompose organic matter, enriching soil nutrients. Peltigera canina, for instance, forms symbiotic relationships with nitrogen-fixing cyanobacteria, boosting nitrogen in forest soil.
    • Habitat and Food Source: Lichens provide habitats and food for various organisms (insects, birds, mammals). Cladonia rangiferina (reindeer lichen) is a crucial winter food source for reindeer and caribou.
    • Air Quality Indicators: Lichens are sensitive to air pollution (especially sulfur dioxide). Their presence/absence indicates pollution levels. Lecanora conizaeoides thrives in polluted environments, indicating high pollution.
    • Ecosystem Monitoring: Lichen diversity and health reflect environmental changes. Lichen surveys monitor impacts of climate change and pollution. Xanthoria parietina is studied for symbiosis and stress tolerance.
    • Climate Change Studies: Lichens' sensitivity to environmental changes is used to study the impacts of climate change, understanding ecological responses. Polar regions (Cladonia arbuscula) exemplify this use in climate change analysis.
    • Cultural and Historical Significance: Lichens have traditional uses in cultures – medicine, dyes, food. Cetraria islandica (Iceland moss) has traditional uses in Icelandic medicine and cuisine.

    Orchid Mycorrhizae

    • Description: Orchid mycorrhizal fungi are crucial for orchid seed germination and early development. Orchid seeds lack sufficient reserves.
    • Structure: Hyphal structures (pelotons) form within orchid root cells.
    • Hosts: Orchidaceae family (orchids).
    • Examples: Rhizoctonia spp. and Ceratobasidium cornigerum form mycorrhizal associations with various orchid species.

    Arbutoid Mycorrhizae

    • Description: Similar to ectomycorrhizae, specifically associated with plant families like Ericaceae. They form a dense hyphal sheath around roots and penetrate root cells.
    • Structure: Dense fungal sheath (hyphal sheath) surrounds root tips and intracellular hyphae form coils or pelotons within root cells.
    • Hosts: Plants like Arbutus and Arctostaphylos.
    • Examples: Arbutus menziesii (Pacific madrone) and Arctostaphylos uva-ursi (Bearberry) form arbutoid mycorrhizal associations.

    Applications in Agriculture

    • Sustainable Agriculture: Mycorrhizae reduce the need for chemical fertilizers and pesticides. Inoculating crops with arbuscular mycorrhizal fungi (e.g. in maize) demonstrates this.
    • Horticulture: Mycorrhizal inoculants enhance the growth and health of ornamental plants, trees, and shrubs (e.g. roses).
    • Forestry: Mycorrhizae aid in tree establishment and growth, important for reforestation and afforestation (e.g. ectomycorrhizal fungi in reforestation projects).
    • Crop Production: Mycorrhizal fungi enhance crop growth and yield (e.g. wheat with arbuscular mycorrhizal fungi).

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz explores the ecological importance of lichens, covering their role in soil formation, nutrient cycling, and as indicators of air quality. Learn how these unique organisms support various habitats and provide food sources for wildlife. Dive into the fascinating ways lichens contribute to environmental health.

    More Like This

    Use Quizgecko on...
    Browser
    Browser