Global Ecology

Question 1

El Niño southern oscilation

Answer 1

sea surface in eastern tropical Pacific Ocean is much warmer than average and atmospheric pressure is lower than average

• rain north and south
• drought in western pacific

Question 2

Ła nina

Answer 2

lower sea surface temperature and higher pressure above pacific

• rain western pacific
• drought north and South America

Question 3

human activity and the nitrogen cycle

Answer 3

increased amount of fixed nitrogen in biosphere

- helps some species at expense of others

Question 4

changes in land cover

Answer 4

rapid changes in global patterns of land use threaten diversity

• agriculture, urbanisation and forestry
• edge effects and effects of isolation mean uninhabited lands are larger

Question 5

human influence on atmospheric concentration

Answer 5

way more CO2! increased temperatures

Question 6

nested subsets

Answer 6

species differ in mobility and vulnerability to local extinction

nested subset approach measures how ordered a collection of communities is
- more nested = more organised

archipelagos:

• land-bridge islands may have similar features to fragmented systems
• sea levels rising isolate islands
• biotas relax through time
• nested subsets patterns through local extinctions
• large islands have more species
• small islands are a subset of the larger and patterns in type and number of species on smaller islands is a subset of large islands