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Questions and Answers
What role do lichens play in soil formation?
What role do lichens play in soil formation?
Which lichen species is known to thrive in polluted environments?
Which lichen species is known to thrive in polluted environments?
How are lichens involved in nutrient cycling?
How are lichens involved in nutrient cycling?
What does the presence of a diverse lichen community suggest about an ecosystem?
What does the presence of a diverse lichen community suggest about an ecosystem?
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Which of the following is NOT a role lichens play in an ecosystem?
Which of the following is NOT a role lichens play in an ecosystem?
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How do lichens contribute to the survival of reindeer and caribou during winter?
How do lichens contribute to the survival of reindeer and caribou during winter?
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Which of these lichens is important in the study of symbiosis and stress tolerance?
Which of these lichens is important in the study of symbiosis and stress tolerance?
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Why are lichens valuable for studying the effects of climate change?
Why are lichens valuable for studying the effects of climate change?
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Which type of mycorrhizae form a dense hyphal sheath around the roots of their host plants?
Which type of mycorrhizae form a dense hyphal sheath around the roots of their host plants?
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Which of the following is an example of a plant that forms arbutoid mycorrhizal associations?
Which of the following is an example of a plant that forms arbutoid mycorrhizal associations?
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What is the primary role of orchid mycorrhizal fungi in the development of orchids?
What is the primary role of orchid mycorrhizal fungi in the development of orchids?
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Which of the following is NOT a benefit of using mycorrhizae in sustainable agriculture?
Which of the following is NOT a benefit of using mycorrhizae in sustainable agriculture?
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Which mycorrhizal association is particularly important for the establishment and growth of forest trees?
Which mycorrhizal association is particularly important for the establishment and growth of forest trees?
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Which of these fungi forms mycorrhizal associations with various orchid species, providing essential nutrients for their growth?
Which of these fungi forms mycorrhizal associations with various orchid species, providing essential nutrients for their growth?
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Which of these mycorrhizal associations are similar to ectomycorrhizae, but specifically associated with certain families like Ericaceae?
Which of these mycorrhizal associations are similar to ectomycorrhizae, but specifically associated with certain families like Ericaceae?
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What is the primary role of pelotons in orchid mycorrhizae?
What is the primary role of pelotons in orchid mycorrhizae?
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Which of these is an example of how mycorrhizae are used in horticulture?
Which of these is an example of how mycorrhizae are used in horticulture?
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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).
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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.