T2 (Ecosystems) Case Studies

Question 1

Realised vs. Fundamental Niche

Answer 1

Joseph Connell’s Barnacles
- Balanus = lower industrial zone
- Chthamalus = upper industrial zone
1 - removed chthamalus from upper = no balanus replaced them so balanus realised niche and fundamental niche the same
2 - Removed Balanus from lower = chthamalus replaced them so balanus better competitor at lower. Fundamental niche of chthamalus different to realised niche - would use lower in no balanus

Question 2

Desert Biome

Answer 2

Cairo, Egypt
Average annual temp 21 degrees
Average annual precipitation 20mm

Question 3

Tropical Rainforest Biome

Answer 3

Phnom Penh, Cambodia
Average annual temp 27 degrees
Average annual precipitation 1390mm

Question 4

Temperate Forest Biome

Answer 4

London
Average annual temp 10.3 degrees
Average annual precipitation 750mm

Question 5

Tundra Biome

Answer 5

Barrow, Alaska
Average annual temp -11.2 degrees
Average annual precipitation 114.3mm

Question 6

Grasslands Biome

Answer 6

Beijing, China
Average annual temp 12 degrees
Average annual precipitation 630mm

Question 7

Food Webs

Answer 7

Effect of harvesting on North Sea food web

• 1970s sand eels harvested and used as animal feed, for fishmeal and for oil and food on salmon farms
• Impact - mackerel, puffin and gannet lost only food source = decline / must switch food source, seals rely more on herring = reduced / must switch food source, Zooplankton increase = more food for jellyfish and herring

Question 8

Food Chain Impacts

Answer 8

Snow leopards, Central Asia mountains

• threatened by effects lower down food chain (overgrazing = less food for its prey = less prey)
• has to prey on livestock as result = leopards attacked and killed by herdsmen
• endangered

Question 9

Succession Example

Answer 9

Sand Dunes

Question 10

K-strategist Example

Answer 10

Humans

Question 11

r-strategist Example

Answer 11

Flour Beetles