Pt7 Flashcards
(14 cards)
Explain the importance of understanding the relationship between biodiversity and community stability.
Understanding this relationship is essential for knowing how many species and of what types can be lost before a community collapses.
Describe the two separate processes that lead to species extinction.
The two processes are:
1. A large population declines due to some cause, and
2. Small populations go extinct.
How does biodiversity affect community stability?
Biodiversity contributes to community stability by providing resilience against species loss, ensuring that ecosystems can function effectively even when some species are lost.
Define community stability in the context of biodiversity.
Community stability refers to the ability of an ecosystem to maintain its structure and function despite disturbances or species loss.
Do small populations have a higher risk of extinction?
Yes, small populations are more vulnerable to extinction due to factors like genetic drift, inbreeding, and environmental changes.
What can cause a large population to decline?
Large populations can decline due to various factors such as habitat loss, climate change, disease, and overexploitation.
Describe the main causes of species declines.
The main causes of species declines include habitat destruction and fragmentation, introduced species, exploitation and over harvesting, pollution, and climate change.
Define the term ‘dead zone’ in marine ecosystems.
A ‘dead zone’ refers to an area in a body of water where oxygen levels are so low that marine life cannot survive, often caused by nutrient pollution.
How does excessive nitrogen fertilizer affect marine ecosystems?
Excessive nitrogen fertilizer runoff promotes algal and bacterial blooms that deplete oxygen in the water, leading to the creation of dead zones.
Do pollution and climate change contribute to species declines?
Yes, pollution and climate change are significant factors that contribute to the decline of various species by altering their habitats and affecting their survival.
Explain the process by which nitrogen runoff leads to algal blooms.
Nitrogen runoff from fertilizers enters water bodies, leading to nutrient enrichment that stimulates algal blooms, which can deplete oxygen and harm aquatic life.
What role does habitat destruction play in species decline?
Habitat destruction reduces the living space and resources available for species, leading to population declines and increased extinction risk.
Describe the effects of introduced species on native ecosystems.
Introduced species can outcompete native species for resources, disrupt food webs, and introduce diseases, leading to declines in native populations.
How does over harvesting contribute to species declines?
Over harvesting depletes populations of species faster than they can reproduce, leading to reduced numbers and potential extinction.
