IB BIOLOGY SL - Unit 8: Human Impacts & Conservation | Quizlet

Negative feedback loop

Returns a system into homeostasis

Positive feedback loop

Amplifies a condition, resulting in more change from homeostasis

Keystone species

A species that has a disproportionately large impact on the ecosystem relative to its population size (removal causes significant biodiversity loss), ex. beaver, wolf, nitrogen-fixing bacteria, etc.

Sustainable resource

Rate at which resources are removed from environment is lower than the rate at which resources naturally replenish themselves

Methods of sustainable resource

- Avoiding use of agro chemicals (use herbivores to eat insects)

- Reduce soil erosion and nutrient loss (avoid drilling, keep plants covered)

- Reduce carbon footprint (use biofuel/energy-powered tractors)

Eutrophication

A process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria

Bioaccumulation

Increase in toxin levels throughout an organism's life

Biomagnification

Increase in toxin levels through the food chain (higher trophic=high toxin)

Rewilding

Encouraging natural ecosystems to return through as few interventions by humans as possible (type of in situ conservation)

Hinewai Reserve

Example of successful rewilding in New Zealand, by adding mammals, returning forest, controlling animals, and lowering interference

Macroplastics

Larger plastics that are known to harm ocean life through entanglement and ingestion

How DDT is accumulated

The inability of natural metabolic processes to break down and remove from system

Short-wave radiation

Form where electromagnetic energy enters the Earth's atmosphere

Long-wave radiation

Form that electromagnetic energy leaves the Earth's atmosphere

Greenhouse gases

Gases in the atmosphere that trap energy, including CO2 (carbon dioxide) and CH4 (methane)

Anthropogenic activities that produce CO2

- Burning forests

- Burning peat/wood

- Combustion of fossil fuels

Anthropogenic activities that produce CH4

- Decay of organic matter in anoxic landfills

- Cattle farming in beef production

- Release of gases by decomposers in a warming wetland/permafrost

Greenhouse effect

Tipping point

Certain threshold that if reached or surpassed can cause massive changes, being irreversible (ex. switch from carbon sink to carbon source of borreal forest, or deforestation in amazon rainforest)

Effects of lack of upwelling due to climate change in oceans

- Less nutrient availability

- Less primary productivity

- Less energy for trophic levels

- Less CO2 taken by ocean

Reasons why species are projected to move up north/higher elevations

- Colder

- Further from equator

- Seeds dispered through north

Effect of increased CO2 in ocean

More acidification (lower pH)

Coral death

Calcium and carbonate levels fall, so calcium pulls hydrogen instead, producing bicarbonate, decreasing calcification

Coral bleaching

Coral expels symbiotes (zooxanthallae) and changes colour to white

Sea ice

Ice that floats on the surface of the sea

Landfast ice

Ice that is attached to the land

Effects of lost of landfast ice on Antartic Emperor penguin

Breeding success decreases as distance from ice edge decreases

Effects of lost of sea ice on Arctic walrus

Decreases survival, leaving offspring unwatched, so young gets eaten

Carbon sequestration

Way to decrease carbon dioxide concentration in atmosphere through capturing and storing in other places (reforestation, afforestation, peat formation)

Advantages of restoring tropical peatland

- Exhibits potential for rapid peat formation

- Sequesters carbon quicker

Advantages of planting non-native species in reforestation efforts

- Grows faster

Advantages of rewilding/planting native species

- Arrive naturally

- Start carbon sequestration

- Supports wildlife

Ecosystem diversity

Variety of habitats (terrestrial/aquatic) found in a geographical area

Species diversity

Number of different species presence, and relative abundance

Genetic diversity

Amount of genetic variation present within a population

Simpson's Reciprocal Index (DI)

N = total, n = for each species

Biodiversity over time

Fluctuated due to evolution

North Island Giant Moa

Anthropogenic species that were hunted by Polynesian people since they were large, couldn't fly, and not fast

Caribbean Monk Seal

Anthropogenic species that European colonists killed for science and food since they were docile, lived near rocks, and approached humans

Splendid Poison Frog

Anthropogenic species that were trafficked for pet trade, with their habitats destroyed and caused outbreak of a fungal disease, since they were colourful, attracted people, and relied on the rainforest

Ways that human activity changed ecosystems

Deforestation, pollution, trashing, over-exploitation of resources, logging

Mixed Dipterocarp Forest in Southeast Asia

Lost ecosystem due to deforestation

Coral reefs (worldwide)

Lost ecosystem due to tourism, climate change, and pollution

IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services)

Established by the UN for research to strengthen and assess biodiversity and ecosystem services, more reliable as there are more people involved and has peer review process

Causes of biodiversity crisis

Pollution, spread of disease/pests, habitat fragmentation, invasive species, clearance of land for agriculture, urbanization, hunting/ over-exploitation of resources

In situ conservation

Way of conserving animals and plants in their natural habitats while maintaining the original biodiversity of the area (national parks, nature reserves, rewilding, etc.)

Ex situ conservation

Way of conserving animals outside their natural habitats (botanic gardens, animal tissue banks, seed banks, zoos, etc.), easier to study for science reasons

EDGE of existence program

A program that generates a score of a species based on uniqueness and endangerment levels, aims to raise awareness, fund research/conservation, and train local to protect species (Chinese giant salamander, long beaked echinda)