Topic 19: Human influences on ecosystems Flashcards
(17 cards)
What is an ecosystem?
An ecosystem is a unit containing a community of organisms and their environment, interacting together.
What is biodiversity?
Biodiversity is the number of different species that live in an area.
What are the reasons for habitat destruction?
(a) Increased area for housing, crop production, and livestock production
(b) Extraction of natural resources
(c) Freshwater and marine pollution
What are the undesirable effects of deforestation?
Reducing biodiversity
Extinction of species
Loss of soil
Flooding
Increase in carbon dioxide in the atmosphere
Why is deforestation harmful?
Deforestation reduces biodiversity, leads to extinction, causes soil erosion, increases flooding, and raises carbon dioxide levels, contributing to global warming.
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?
(a) Monitoring and protecting species and habitats
(b) Education
(c) Captive breeding programmes
(d) Seed banks
Why has food production increased?
Due to agricultural machinery, chemical fertilizers, insecticides, herbicides, selective breeding, and large-scale monoculture.
What are the positive impacts of large-scale monoculture?
Increased yield
Lower food prices
Reduced labor costs
What are the negative impacts of large-scale monoculture?
Vulnerability to natural disasters
Increased pest and disease risks
Reduced biodiversity
Resistance to pesticides
What are the negative impacts of intensive livestock production?
Welfare issues for livestock
Easy spread of diseases
Pollution of land and waterways
What are the effects of pesticides on the environment?
Insecticides can kill beneficial insects like bees
Herbicides can harm animals that eat plants
Bioaccumulation of toxins
What is the problem with non-biodegradable plastics?
Plastics can choke animals, fill their stomachs, and accumulate in rivers, harming ecosystems.
What is global warming?
Global warming is the increase in the Earth’s average temperature, primarily caused by the burning of fossil fuels, leading to increased carbon dioxide and methane levels.
What is a sustainable resource?
A sustainable resource is one that is produced at the same rate it is consumed, ensuring it does not run out.
How can forests be conserved?
Through education, protected areas, quotas, and replanting efforts.
Why do we need to conserve species and habitats?
To maintain biodiversity, protect ecosystem functions, and secure resources like food, medicine, and genetic material.
