Question

invasive species
indicator species
endangered species
analysis question
which of the following types of species (from the list above) would you think impacts biodiversity the most? * provide 2 reasons to support your answer.

Explanation:

• Invasive species:
• Definition: Non - native species that cause harm to the environment, economy, or human health.
• Examples: Zebra mussels (Dreissena polymorpha) in North American waterways, cane toads (Rhinella marina) in Australia.
• Role in the ecosystem: Compete with native species for resources (e.g., food, space). They can also prey on native species, disrupt food webs. For example, zebra mussels filter large amounts of plankton, reducing food availability for native fish.
• Human factor: Often introduced accidentally (e.g., via ballast water in ships) or intentionally (e.g., for horticulture, as in the case of some invasive plants).
• Indicator species:
• Definition: Species whose presence, absence, or abundance reflects the environmental conditions of an ecosystem.
• Examples: Trout (Salmo trutta) are indicators of clean, cold water. Lichens are indicators of air quality (sensitive to sulfur dioxide).
• Role in the ecosystem: Help in monitoring ecosystem health. For example, if trout populations decline, it may indicate water pollution or changes in water temperature.
• Human factor: Used by environmental scientists and policymakers to assess and manage ecosystems.
• Endangered species:
• Definition: Species that are at risk of extinction.
• Examples: Giant pandas (Ailuropoda melanoleuca), Amur leopards (Panthera pardus orientalis).
• Role in the ecosystem: Play important roles in their ecosystems. For example, pandas help in seed dispersal (though their main role is more cultural and as an umbrella species for conservation of their habitat). Amur leopards are top predators that help control prey populations.
• Human factor: Threatened by habitat loss (e.g., deforestation for agriculture, urbanization), poaching, and climate change.

For the analysis question:
Invasive species impact biodiversity the most.

• Reason 1: They out - compete native species. Invasive species often have no natural predators in the new ecosystem. For example, in Lake Victoria, the Nile perch (Lates niloticus, an invasive species) caused the extinction of many native cichlid fish species by preying on them and competing for food.
• Reason 2: They disrupt ecological processes. Invasive plants like kudzu (Pueraria montana var. lobata) in the southeastern United States can cover large areas, reducing light availability for native plants, altering soil nutrient cycling, and changing the hydrology of an area.

Answer:

• Invasive species:
• Definition: Non - native species that cause harm.
• Examples: Zebra mussels, cane toads.
• Role: Compete, prey, disrupt webs.
• Human factor: Accidental/intentional introduction.
• Indicator species:
• Definition: Reflects ecosystem conditions.
• Examples: Trout, lichens.
• Role: Monitor health.
• Human factor: Used for assessment.
• Endangered species:
• Definition: At risk of extinction.
• Examples: Giant pandas, Amur leopards.
• Role: Play important ecological roles.
• Human factor: Threatened by habitat loss etc.
• Analysis: Invasive species. Reasons: Out - compete natives (e.g., Nile perch - cichlids), disrupt ecological processes (e.g., kudzu).