Unit 4 Notes Flashcards
What is Biodiversity?
The number and variety of organisms within an area.
How can Biodiversity be measured?
Species diversity, Ecosystem diversity, Genetic diversity.
What is Species diversity?
The number and variety of different species within an area.
What is Habitat Diversity?
The variations in ecosystems within a specific geographic area.
What is Genetic Diversity?
The variety of genes within a species population.
What is Biodiversity distribution?
The general global pattern of biodiversity.
Which factors affect the relationship between latitude and species diversity?
Sunlight, rainfall, nutrients.
What are the threats to biodiversity?
Habitat loss and degradation, species overexploitation, pollution, invasive species, climate change.
How is Habitat loss a threat to biodiversity?
Modification of the environment where a species lives, by removal, fragmentation, or reduction in quality.
How is species overexploitation a threat to biodiversity?
Direct and indirect forms, unsustainable hunting and poaching.
How is pollution a threat to biodiversity?
Can directly affect a species by making the environment unsuitable for survival such as oil spills.
How is invasive species a threat to biodiversity?
Can compete with native species for space, food and other resources. Spreads diseased not previously present.
How is climate change a threat to biodiversity?
Some species will have to adapt by shifting range to track suitable climate.
What are direct threats to biodiversity?
Immediate human activities that have a direct impact on the area in which the activities are undertaken.
What are indirect threats to biodiversity?
Human activities which may impact ecosystems globally through the consequences of these actions.
What are the examples of direct threats?
Deforestation, Overfishing, Agriculture, Energy extraction, peat extraction.
What are the examples of indirect threats?
Oil spill, eutrophic dead zones, climate change, forest fires, melting permafrost, ocean acidification, rising sea levels.
What are the local threats to biodiversity?
Land use change, pollution, resource exploitation, exotic species.
Are local threats to biodiversity usually direct or indirect?
Direct.
Are global threats to biodiversity usually direct or indirect?
Indirect.
What % of plant and animal species do tropical rainforests contain?
50%.
What are the direct threats to tropical rainforests?
Mining causes deforestation and release of toxic chemicals, infrastructure projects, flooding caused by deforestation, logging and felling, plantation farming, ranching.
What are the indirect threats to tropical rainforests?
Climate change - more forest fires, reduced rainfall. Land degraded by human activity.
What % of the earth’s land did tropical rainforests cover 100 years ago?
15%.
What % of the earth’s land do tropical rainforests cover now?
Less than 3%.
What % of tropical rainforests have been destroyed in the last 50 years?
1/3.
What % of deforestation is due to agriculture?
80%.
What is an example of peatland used for cattle?
The Amazon.
Which countries use palm oil plantations?
Congo, Indonesia.
Why is deforestation increasing in the Amazon?
Agriculture, redevelopment of land, illegal logging, cattle grazing, cutting environmental budget.
What are the reasons for increased demand for timber and agricultural land?
Increased people, money, need for resources, changed in indirect tax.
How is logging a threat to tropical rainforests?
Hardwood such as mahogany and teak are very valuable, and can be sold for profit.
What is an example of logging in the rainforest?
West Africa - 90% of the rainforest has been destroyed.
Why is cattle grazing a threat to tropical rainforests?
Growing beef, allowing land to be sold. Hurts the environment.
How are Soya plantations a threat to rainforests?
Intensively farmed animals are fed with soya. Top soil is washed away.
What is an example of soya plantations?
China - Growing demand for beef, largest consumer of soya from Brazil.
How is palm oil a threat to rainforests?
Land is cleared, then replanted with cash crops. Valuable trees are harvested, the rest are burnt to clear the land, causing pollution.
What % of palm oil comes from Malaysia and Indonesia?
80%.
What is the practice of palm oil plantations in Indonesia?
Burning peatlands below, storing a lot of carbon. 4% of greenhouse gases.
How does mining affect tropical rainforests?
Mineral and gold deposits, as a source of income. Mercury is used to extract gold, polluting river systems - second worst source of river pollution.
What % of exports are Mercury in Indonesia?
19%.
How does hydroelectricity affect tropical rainforests?
Building of hydroelectric dams, results in major flooding, harming wildlife, changes ecosystem of river downstream.
What is the Xingu River?
The third largest hydroelectric dam.
Why are landgrabs an increasing problem in the Amazon?
In the last 30 years, 17% of the Amazon has gone. New laws threatening the rainforest with further destruction. Illegal land grabbers grab land from protected areas and indigenous communities. Laws weren’t enforced during COVID.
How much land is lost every minute from the Amazon?
3 football pitches’ worth.
What are the first three steps of plant die off?
Drought and wildfires increase, more trees die and decompose or burn, releasing C02, fewer rainforest trees mean less water is pumped into the atmosphere.
What are the last two steps of plant die off?
Rainfall decreases, temperature rise, rainforest die off.
Why is plant die off concerning?
Because most trees can’t grow, and the rainforest can’t sustain itself, leading to habitants dying, rainforest area decreases, decreasing biodiversity.
How are tropical forest water and nutrient cycles affected by deforestation?
Crops are re-harvested every 10-20 years, meaning that crops release more C02 than they absorb. Monoculture decreases diversity, meaning ecosystems can’t thrive in this area. Less nutrients stored - soil store is smaller.
What has a recent solution to reduce biodiversity loss been?
COP26 - End and reverse deforestation by 2030. £14 Billion of public and private funds given to achieve this.
What is a disadvantage of this?
Many previous plans haven’t achieved their goals, and deforestation has increased.
What area do coral reefs cover?
280,000km of shallow tropical marine areas between 30 degrees N and S.
What % of fish have habitats in coral reefs?
Over 25%.
What temperature must the ocean be for coral reefs to form?
18 degrees.
What must water depth be for coral reefs to form?
Less than 30m.
What is Coral?
An animal which captures food with its’ tentacles, attached itself to reef by secreting acalcium carbonate shell.
How is climate change an indirect threat to coral reefs?
It leads to coral bleaching.
What are the direct threats to coral reefs?
Overfishing, destructive fishing practices, tourism development, marine pollution.
What is the status of coral reefs?
14% of global coral reefs have been killed by bleaching since 2007. 24% of global reefs are under imminent risk of collapse.
How does anthropogenic activity lead to coral bleaching?
Increased ocean temperature due to climate change pollution, leads to less algae within coral reefs, coral dies above 35 degrees, hotter atmosphere.
What is Assisted Evolution?
Taking samples of coral in the wild, growing them together.
How does Assisted evolution help maintain biodiversity of coral reefs?
Ones which survive higher temperatures crossbreed to produce offspring. These can survive higher temperatures. Planting these back in the wild means new breeds have higher tolerance.
What are the threats to coral reefs of fishing?
25% of the world’s fish supplies come from coral reefs. In East Asia, coral reefs provide food for 1 Billion people. 55% of the world’s coral reefs are affected by overfishing.
What is Dynamite fishing?
Blowing up fish indiscriminately to catch them.
Why do fishermen use dynamite fishing?
Because they don’t have actual fishing equipment, and ensures easy, cheap, large catches.
What is the disadvantage of dynamite fishing?
It wipes out all other types of fish, and damages the coral reef, meaning future fish numbers decrease.
How could dynamite fishing be controlled?
With government intervention, as they will die out otherwise, and requires government investment.
What % of coral reefs are affected by agricultural runoff?
25%.
Where can pollution come from?
Sewage, agricultural runoff, industrial waste.
What can some nutrients cause?
Eutrophication, which can block necessary sunlight that corals need to survive.
What is an example of a coral reef facing a pollution threat?
Abbot Point coral port.
What will dredging mean for abbot point?
Destruction of reef, mud will go into the ocean, spreading pollution. Wind goes into a shorewind direction, can blow soot into the reef’s direction.
What are the threats to biodiversity in wetlands?
They support 40% of global biodiversity, 1/4 of these could go extinct. They perform ecological functions - water storage, purification, carbon storage.
What is the case study of a wetland?
Pantanal, South America.
Why is Pantanal important?
It’s the world’s largest wetland - 42 million acres. Supports 1.5 million people economically, faces direct and indirect threats.
Where is Pantanal located within the ecosystem?
In a lowland basin, surrounded by Brazil, Bolivia, Paraguay.
How Biodiverse is the Pantanal?
4000 registered plant and animal species, 656 different types of tree, 325 species of fish.
How do land use changes in uplands of the Paraguay river basin threaten wetlands?
In the upland areas surrounding the basin, 60% of forests have been removed, replaced with intensive farming. Causes eutrophication, soil erosion, hydroelectric power. Material moves into lowland area.
What is the WWF campaigning for in the Pantanal?
Recuperation of over 80 springs, installation of over 40 environmentally friendly septic tanks. Incentive to construct three nurseries, growing seedlings, 160km of environmentally adequate rural roads.
What are the Indirect threats in the Pantanal?
Over 70,000 sq. km of marsh and forest land have burned in the Pantanal in the last 3 years. The area is becoming drier due to wildfires, 3506 fires in first half of 2020 - 192% increase.
What are the current threats to the Pantanal?
Cutting, drainage of peat, Invasive species of colonising area, climate change could make water level decrease, increased fire risk.
