4 - cycles and mass extinction

Define cycling

movement of matter from non-living to living compartments and back

List 2 things that organisms do in ecosystems

• energy capture and conversion

• elemental cycling

State two ways that carbon can be sequestered

• photosynthesis

• calcification

What is the dominant terrestrial sink of atmospheric CO2?

soil

What accounts for 80% of anthropogenic CO2 emissions?

fossil fuel burning

Is the ocean overall becoming more acidic or alkaline and why?

acidic due to increased CO2 in the atmosphere

Why may calcification not be able to ameliorate the effects of increased CO2 emissions?

animals capable of calcification may not be able to adapt

List 4 major pressures on ecosystems and species

• climate change

• deforestation and habitat fragmentation

• desertification

• pollution

Give an example of human driven extinction in land animals

the north american bison was hunted to near extintion

Give an example of human driven extinction in aquatic animals

demand for shark fin soup has lead to be a 70% loss of population in 50 years

Give an example on how temperature influences species coexistence

outcome of competition is reversed by increasing temperature in S.malma and S.leucomenis

Give an example of increased desertification

the Murray-Darling river in australia almost disappears each summer

Give an example of effects of climate change in high altitudes

polar bears have been found swimming 100s of Kms beyond their normal range

Give an example of effects of climate change in the ocean

zooxanthellae die as temperatures rise, leaving bleached corals

Give an example of effects of climate change in terms of weather

oceans provide increased energy for storms as temperatures rise, leading hurricanes to become stronger & more severe