3.2 Human Impact on Biodiversity (DP IB Environmental Systems & Societies (ESS): HL): Flashcards

Cumulative effects are the amplified negative impacts on ecosystems when multiple human threats act together, reducing ecosystem resilience.

False.

Pollution and climate change are indirect threats to biodiversity, not direct threats.

The conservation status of a species is an assessment of how at risk it is of extinction, based on population trends, threats, and other factors.

The main role of the IUCN is to act as the global authority on the status of the natural world and to assess the conservation status of animal and plant species worldwide.

The IUCN uses data and modelling to estimate the category each species should be in.

Three factors used to determine conservation status are population size, rate of population change, and degree of habitat fragmentation.

Species are placed into categories such as vulnerable, endangered, and extinct, depending on population numbers and threats.

An endemic species is a species that is only found in a specific, usually restricted, geographic area.

True.

Animals at higher trophic levels tend to have smaller populations and are more vulnerable to ecosystem changes, increasing their risk of extinction.

When there is not enough data to assess a species, it is classed as data deficient.

The IUCN Red List of Threatened Species™ is a public, global list that categorises species according to their risk of extinction.

Habitat fragmentation is the process in which large, continuous habitats are broken into smaller, isolated sections, reducing habitat quality and connectivity.

International cooperation is essential because many species migrate or range across borders, and global threats require coordinated policies and actions for effective conservation.

As of 2023, extinction risk has been evaluated for less than 5% of the world's described species.

An extinct species is a species for which there are no living individuals remaining anywhere in the world.

The extinction of the Passenger pigeon was caused by overhunting and habitat destruction.

The last known Tasmanian tiger died in captivity in 1936, marking the extinction of the species.

True.

The last Passenger pigeon died in 1914, marking the extinction of the species.

A critically endangered species is a species facing an extremely high risk of extinction in the wild in the immediate future.

The main threats to the Sumatran orangutan are habitat destruction, illegal hunting, and capture for the pet trade.

The black rhinoceros is critically endangered, with only around 3,000 mature individuals remaining in the wild.

The Southern white rhinoceros has recovered due to increased law enforcement, habitat protection, and captive breeding programs.

True.

The bald eagle population increased after DDT and other harmful pesticides were banned, along with other conservation efforts.

The bald eagle is native to North America and is an example of a species whose conservation status has improved thanks to human intervention.

Habitat destruction is the process by which a natural habitat becomes incapable of supporting its native species, often due to human activities such as logging and agriculture.

The black rhinoceros population declined by over 90% due to poaching for their horns, habitat loss, and civil unrest in their range countries.

The tragedy of the commons describes the overuse and depletion of a shared resource when individuals act in their own self-interest rather than for the common good, leading to the resource becoming unavailable for future use.

When individuals act in their own self-interest with a shared resource, it leads to degradation of the resource, making it unavailable for future use.

The tragedy of the commons can also involve the contamination and degradation of ecosystems by humans.

False.

The tragedy of the commons can also occur through contamination or degradation of ecosystems, not just overharvesting.

Many natural resources are used faster than they can be replenished, leading to resource depletion.

Overexploiting natural resources can result in resource depletion and could eventually lead to the collapse of certain ecosystems.

The tragedy of the commons can cause the loss of habitats and species, reduce genetic diversity, and weaken ecosystem resilience.

Overfishing of cod on the Grand Banks led to a dramatic decline in cod populations, economic collapse of the fishing industry, and long-term ecological damage.

Habitat destruction is the process in which natural environments are damaged or eliminated, leading to a loss of biodiversity.

The most significant threat to biodiversity hotspots is habitat destruction.

Deforestation in tropical rainforests is a major cause of habitat loss.

Deforestation in the Amazon Rainforest results in habitat loss for species like the jaguar and giant river otter.

Large-scale slash and burn agriculture is a major human activity causing deforestation.

Three human activities that contribute to deforestation are: agriculture (especially slash and burn), mining, and logging.

Human-induced climate change is associated with increasing frequency and severity of wildfires.

Fragmentation is when a large, continuous habitat is broken into smaller, isolated sections, making it harder for species to survive and reproduce.

True.

Fragmentation isolates populations, making it harder for individuals to find mates, food, and safe habitats.

No, biodiversity is not evenly distributed; it is concentrated in biodiversity hotspots, many of which are in developing countries.

Many biodiversity hotspots are located in developing countries around the tropics.

Conservation strategies can conflict with economic development because local people often depend on natural resources for their livelihoods, so protecting habitats may limit economic opportunities.

A lack of funding makes it difficult for developing countries to implement effective conservation strategies to protect biodiversity hotspots.

A key biodiversity area (KBA) is a place identified as globally important for the conservation of biodiversity.

KBAs are prioritised for conservation because they are crucial for the survival of species and ecosystems, especially those at risk of extinction or collapse.

KBAs are identified based on specific scientific criteria that ensure they contribute significantly to the global persistence of biodiversity.

A key criterion for identifying a KBA is the presence of threatened species that are listed as vulnerable, endangered, or critically endangered on the IUCN Red List.

Ecosystems that are at risk of collapse are a criterion for KBA identification.

Restricted-range species are species that have a limited geographical range. Their presence makes an area a KBA because such areas are often the only places these species exist.

Ecological integrity means the area remains ecologically intact and largely unaffected by industrial human influence, supporting natural ecological processes.

The Atlantic Forest in Brazil is a KBA because it is one of the most biologically diverse regions in the world, home to many endangered species and unique habitats.

The Sundarbans is the largest mangrove forest in the world and a critical area for global biodiversity.

True.

The Western Ghats support a wide variety of ecosystems and many endemic species, making them a global biodiversity hotspot.

One major threat to the Atlantic Forest is deforestation for agriculture and urban development, which reduces habitat for many species.

Palm oil plantations often expand into key biodiversity areas in Malaysia and Indonesia, leading to deforestation and loss of habitat.

Sustainable palm oil production aims to reduce biodiversity loss by implementing standards that limit deforestation and protect critical habitats, such as those set by the Roundtable on Sustainable Palm Oil (RSPO).

Traditional Indigenous land management refers to the methods used by Indigenous communities to care for and sustain the natural environment over generations.

The primary goal is to ensure long-term sustainability of the land so it remains productive and healthy for future generations.

Many Indigenous land management methods are based on a deep connection to the land and a holistic understanding of ecosystems.

Rotational farming is an agricultural practice where different plots of land are cultivated in succession to allow soil to regenerate between planting cycles.

Controlled burning is the deliberate use of fire by Indigenous peoples to manage forests, promote biodiversity, and reduce the risk of large wildfires.

Sustainable fishing and hunting are traditional Indigenous practices that help maintain balance in ecosystems.

True.

Indigenous methods focus on working with nature and preserving biodiversity, making them more sustainable than many modern approaches.

It allows the soil to regenerate between planting cycles, which prevents nutrient depletion and supports long-term land productivity.

Indigenous Australians have long used fire-stick farming (controlled burning) to manage forests and promote the growth of certain plants and animals.

External threats include population growth and economic development, as well as climate change, both of which put pressure on Indigenous lands and disrupt traditional practices.

Climate change has made flooding more extreme, submerging farms and affecting crop growth, which leads to food insecurity for Indigenous communities.

A significant internal threat to Indigenous land management is the erosion of traditional ecological knowledge.