unit 20 bio - Human Influences on Ecosystems

What has increased food production in agriculture?

Use of agricultural machinery, chemical fertilisers, insecticides, herbicides, and selective breeding

How does agricultural machinery improve food production?

By allowing the use of larger areas of land and improving efficiency

How do chemical fertilisers improve food production?

By improving yields

How do insecticides improve food production?

By improving quality and yield by controlling pests

How do herbicides improve food production?

By reducing competition with weeds

How does selective breeding improve food production?

By improving production in crop plants and livestock

What are the advantages of large-scale monocultures?

Higher efficiency, easier management, and higher yields

What are the disadvantages of large-scale monocultures?

Reduced biodiversity, increased vulnerability to pests, and soil depletion

What are the advantages of intensive livestock production?

Higher food production, more efficient use of land

What are the disadvantages of intensive livestock production?

Poor animal welfare, environmental pollution, and high resource use

What is biodiversity?

The number of different species in an area

What are the reasons for habitat destruction?

Increased area for housing, crop and livestock production, extraction of natural resources, and pollution

How do humans negatively impact habitats?

By altering food webs and food chains

What are the undesirable effects of deforestation?

Reduced biodiversity, extinction, loss of soil, flooding, and increased CO2 in the atmosphere

What are the effects of untreated sewage and excess fertiliser on aquatic ecosystems?

Eutrophication, oxygen depletion, and harm to aquatic life

What is eutrophication?

The process where increased nitrate and ion availability leads to excessive producer growth, decomposition, oxygen depletion, and death of aquatic organisms

What are the effects of non-biodegradable plastics on ecosystems?

Harm to terrestrial and aquatic ecosystems due to accumulation and toxicity

What are the sources and effects of methane and carbon dioxide pollution in the air?

Enhanced greenhouse effect and climate change

What is a sustainable resource?

A resource that is produced as rapidly as it is removed, so it does not run out

Which resources can be conserved and managed sustainably?

Forests and fish stocks

How can forests be conserved?

Through education, protected areas, quotas, and replanting

How can fish stocks be conserved?

Through education, closed seasons, protected areas, controlled net types, quotas, and monitoring

Why do organisms become endangered or extinct?

Due to climate change, habitat destruction, hunting, overharvesting, pollution, and introduced species

How can endangered species be conserved?

Through monitoring, protecting species and habitats, education, captive breeding, and seed banks

Why are conservation programmes important?

To maintain or increase biodiversity, reduce extinction, protect ecosystems, and maintain ecosystem functions

What is the role of artificial insemination (AI) and in vitro fertilisation (IVF) in conservation?

They are used in captive breeding programmes to help preserve endangered species

What are the risks to a species if its population decreases?

Reduced genetic variation, leading to inbreeding and loss of adaptability