Chapter 9: Natural Ecosystems and Human Activities Flashcards
What is an ecosystem?
A: An ecosystem includes all the living things (biotic components) and all the non-living things (abiotic components) in an area.
Q: What is a habitat?
A: A habitat is the place within an ecosystem where an organism lives.
Q: Define “population” in ecological terms.
A: A population is all the organisms of one species living in a defined area at the same time.
Q: What does “niche” refer to in ecology?
A: A niche is the role of a species within the ecosystem.
Q: How does a food web differ from a food chain?
A: A food web shows the relationship between all or most of the producers, primary, secondary, and tertiary consumers in an ecosystem, unlike a food chain which focuses on a single pathway.
Q: What is a community in an ecosystem?
A: A community is a group of populations of different species that live together in an area and interact with each other.
Q: Name an important function of wetlands.
A: Wetlands provide shoreline protection, maintain water quality, control floods, recharge aquifers, and offer habitats.
Q: Explain the concept of a pyramid of numbers.
A: A pyramid of numbers represents the number of organisms at each trophic level in an ecosystem by a horizontal bar whose length is proportional to the numbers at that level.
Q: What is a food chain?
A: A food chain is a diagram showing the relationship between a single producer and primary, secondary, and tertiary consumers.
Q: Explain predation.
A: Predation is when one animal eats another animal.
Q: Describe tertiary consumers.
A: Tertiary consumers derive their food from secondary consumers.
Q: What role do primary consumers play in an ecosystem?
A: Primary consumers derive their food from producers.
Q: Why do food chains typically have no more than 4 or 5 trophic levels?
A: Food chains have limited trophic levels because energy is lost at each level due to heat, cellular respiration, growth, feces, and incomplete digestion.
Q: Define “producers” in an ecosystem.
A: Producers are organisms within an ecosystem that can carry out photosynthesis.
Q: What is a trophic level?
A: A trophic level is a feeding level within a food chain or food web.
Q: What do decomposers do in an ecosystem?
A: Decomposers derive their food from the bodies of dead organisms.
Q: Why is nitrogen important for plants?
A: Nitrogen is essential for synthesizing proteins and other vital substances in plants, contributing to growth and development.
Q: What does relative humidity (RH) measure?
A: Relative humidity measures how damp the air is, expressed as a percentage of the maximum amount of water vapor the air can hold if fully saturated.
Q: How does deforestation contribute to climate change?
A: Deforestation increases CO2 levels in the atmosphere by releasing carbon stored in trees and reducing the number of trees available for photosynthesis.
Q: What are secondary consumers?
A: Secondary consumers are organisms that derive their food from primary consumers.
Q: What is pollination?
A: Pollination is the transfer of pollen grains from the anther to the stigma for fertilization to occur.
Q: What are some causes of habitat loss?
A: Causes include drainage of wetlands, intensive agricultural practices, and deforestation.
Q: What is deforestation, and what are its impacts?
A: Deforestation is the clearance of forests, leading to habitat loss, soil erosion, and contributions to climate change.
Q: What is sustainable tourism?
A: Sustainable tourism involves managing tourism in a way that prevents damage to habitats and ensures the growth of the tourist industry is dependent on maintaining the environment.
Q: Why is water important for plants?
A: Water is essential for photosynthesis and serves as a medium for chemical reactions. It is also crucial for plant growth and determines where plant species can live.
Q: How is temperature expressed in ecological studies?
A: Temperature is usually expressed in degrees Celsius (°C).
Q: What is the role of oxygen in aquatic ecosystems?
A: Oxygen is needed for respiration in aquatic organisms and is usually expressed in parts per million (ppm) in water.
Q: What is the significance of light in ecosystems?
A: Light is essential for photosynthesis and is expressed in lumens.
Q: What are the main biotic factors in an ecosystem?
A: The main biotic factors are producers, primary consumers, secondary consumers, tertiary consumers, and decomposers.
Q: What is competition in an ecosystem?
A: Competition occurs when living things vie for a range of resources from the environment, leading to the survival of the most adapted individuals.
Q: Describe the process of photosynthesis.
A: Photosynthesis is the process by which plants trap light energy using chlorophyll, split water into hydrogen and oxygen, combine hydrogen with CO2 to produce glucose, and release oxygen as a byproduct.
Q: What is brackish water?
A: Brackish water is water with salinity levels between freshwater and seawater, typically ranging from >0 ppt but <35 ppt.
Q: What are the benefits of selective logging?
A: Selective logging removes only mature trees, allowing the forest to regenerate, preserving biodiversity, and reducing environmental impact compared to clear-cutting.
Q: What is a carbon sink?
A: A carbon sink is a vegetated area where the intake of CO2 from the atmosphere in photosynthesis exceeds its output from respiration.
Q: How can zoos help in conservation?
A: Zoos provide education, conduct scientific research, and run captive-breeding programs to increase species numbers and maintain genetic diversity.
Q: How does salinity affect aquatic organisms?
A: Salinity, or the salt concentration in water, affects aquatic organisms’ ability to regulate water and electrolytes. Different species are adapted to specific salinity ranges.
Q: What is sustainable forestry?
A: Sustainable forestry involves practices like selective logging and agroforestry to maintain forest health and productivity over time.
Q: What is the significance of the pH level in ecosystems?
A: pH levels affect the availability of nutrients and the health of organisms. Extreme pH levels can harm aquatic life and disrupt ecosystem functions.
Q: What is the purpose of a seed bank?
A: Seed banks store seeds to preserve genetic diversity and protect against the loss of endangered plant species.
Q: What are the advantages and disadvantages of quadrat sampling?
A: Advantages include being quick, inexpensive, and portable; disadvantages include potential bias and inaccuracy if not enough quadrats are used.
Q: What is genetic depletion, and why is it a concern?
A: Genetic depletion is the loss of genetic diversity within a species, which can reduce adaptability and resilience to environmental changes.
Q: What are some key impacts of deforestation on soil and climate?
A: Deforestation leads to soil erosion, reduced soil fertility, and increased carbon dioxide levels, contributing to climate change.
Q: What is a pooter used for in ecological studies?
A: A pooter is used to collect small, non-sedentary organisms like insects by suctioning them into a container.
Q: What is the role of decomposers in the nutrient cycle?
Q: What is the role of decomposers in the nutrient cycle?
Q: What happens during competition between organisms?
A: Organisms compete for resources such as food, water, and shelter, leading to survival of the fittest and often affecting population dynamics.
Q: Explain the impact of overcultivation on ecosystems.
A: Overcultivation leads to soil erosion and habitat loss, negatively affecting soil health and biodiversity.
Q: What are climax communities?
A: Climax communities are stable ecological communities with balanced populations of plants and animals adapted to the local environment.
Q: What are wildlife corridors and their importance?
A: Wildlife corridors are areas of habitat that connect larger habitats, allowing animals to migrate, find resources, and maintain genetic diversity.
Q: How do national parks contribute to conservation?
A: National parks protect ecosystems and biodiversity by restricting activities like hunting and logging, and providing facilities for education and sustainable tourism.
Q: What is the main goal of ecotourism?
A: The main goal of ecotourism is to promote conservation of the environment while allowing people to appreciate and learn about natural areas.
Q: What are the main forms of biotic interactions in ecosystems?
A: The main forms include competition, predation, and pollination.
Q: What is the purpose of a seed bank?
A: Seed banks store seeds from various plant species to preserve genetic diversity and ensure availability for future restoration and research efforts.
Q: How do zoos contribute to biodiversity conservation?
A: Zoos contribute by educating the public, conducting research, and running captive-breeding programs to support endangered species.
Q: Explain the concept of sustainable harvesting.
A: Sustainable harvesting involves managing the collection of wild resources in a way that does not deplete the resource and allows it to regenerate for future use.
Q: What is alley cropping?
A: Alley cropping involves planting rows of trees with crops grown in the spaces between, combining tree benefits with crop production.
Q: What is agroforestry and its benefits?
A: Agroforestry integrates trees and shrubs into agricultural systems, enhancing soil fertility, providing habitats, and improving biodiversity.
Q: Describe the role of biosphere reserves.
A: Biosphere reserves are areas designated for conservation, research, and education, promoting sustainable development while protecting unique ecosystems and species.
Q: How does the concept of carbon sinks relate to climate change?
A: Carbon sinks absorb more CO2 than they emit, helping to mitigate climate change by reducing the amount of CO2 in the atmosphere.
Q: What is the impact of soil erosion on ecosystems?
A: Soil erosion depletes soil nutrients, reduces land productivity, and can lead to habitat loss and sedimentation in water bodies.
Q: What are extractive reserves and their purpose?
A: Extractive reserves are areas where local communities have rights to use natural resources sustainably, balancing conservation with economic benefits.
