Chapter 56 - Conservation Biology + Global Change

Distinguish between the different types of diversity and their importance for conservation.

Genetic diversity: among the genes in a population; species diversity: number of species; ecosystem diversity: variety of ecosystems across landscapes; humans threaten biodiversity at all three levels

Explain what the sixth extinction is.

The current rapid human-induced extinction event in the Anthropocene with extinction rates 100–1,000× background levels

Describe the importance of genetic diversity

Extinction reduces diversity required for evolution; small populations with low genetic diversity have increased extinction risk

Explain the four ecosystem services categories and give an example of each.

Provisioning, regulating, supporting, cultural

List and describe the major threats to biodiversity.

Habitat loss, overharvesting, introduced species, global changes

Endangered vs threatened.

Endangered – risk of extinction; threatened – likely to become endangered

Explain human effects on our global ecosystem

Nutrient enrichment, toxins, climate change, ozone depletion

Extinction vortex

Inbreeding and genetic drift draw a small population down toward loss of individuals

Habitat loss and fragmentation, what does it do?

Creates small isolated populations more likely to go extinct

Describe overharvesting and give an example.

Harvesting organisms faster than they can repopulate; examples: Bluefin tuna, elephant tusks, shark fins

Describe introduced vs invasive species.

Introduced: moved by humans; invasive: substantial negative effects, no limiting factors

Know an example, problem, and solution of introduced species examples covered in class and their effects.

Mongoose

• brought to HI in 1883 by the sugar industry to control rats bc they were damaging crops

• prey heavily on native species: birds, small mammals, eggs of birds and sea turtles…

• control: traps and poison

Explain how the Prairie chicken is an example of an extinction vortex and how it was ‘fixed’

Habitat loss caused small populations and low genetic diversity; importing birds increased genetic variation and reversed decline

An extinction vortex happens when a population becomes so small that inbreeding and low genetic diversity make it even weaker, causing the population to shrink faster and faster. The Prairie Chicken fell into this vortex after habitat loss reduced its numbers, but scientists “fixed” it by bringing in birds from other states to increase genetic diversity and boost survival.

Describe corridors and why they are important.

Corridors connect isolated patches, decrease fragmentation, increase gene flow, but can increase disease spread

Explain what a biodiversity hotspot is and why it is important for conservation biology.

Areas with high endemic species; 44% of vascular plants and 35% of vertebrates found in 1.4% of land

List the different types of protected areas.

Nature reserves; zoned reserves (paired with land for economic use)

Predict the outcome of exceeding the critical load of soil.

Exceeding the critical load of soil means more pollutants (like nitrogen or acid deposition) enter the soil than it can safely handle.
When this happens, the soil becomes acidic and nutrient-poor, leading to plant stress, loss of biodiversity, weaker forests, and long-term ecosystem damage.

Explain bioaccumulation and biomagnification.

Bioaccumulation: toxins collect in tissues; biomagnification: toxins increase concentration up food chains

Describe the different types of pollutants and their effects.

Toxins (PCBs, DDT), pharmaceuticals (affect fish brains, feminization), mercury, microplastics, endocrine disruptors like BPA

Explain how and if r and k selected species are at risk for extinction.

K-selected species more at risk due to low reproductive rates; r-selected less vulnerable

Microplastics

Plastics broken into small particles found in marine systems, organisms, atmosphere, water, and human blood

Greenhouse effect

Greenhouse gases trap heat in Earth’s atmosphere, warming the planet