World Ecosystems

Question 1

What is an ecosystem?

Answer 1

A large, relatively distinct region characterised by similar climatic conditions and plants.

Question 2

What is a biome?

Answer 2

A series of similar, but unconnected ecosystems examined across the globe.

Question 3

What is climate?

Answer 3

Weather conditions over a long period of time.

Question 4

What are the main determinants of vegetation type and why?

Answer 4

Temperature and moisture, because they affect photosynthesis.

Question 5

Name two Tundra climates you know of…

Answer 5

Arctic and Alpine

Question 6

What distinguishes an arctic tundra?

Answer 6

-extreme northern latitudes wherever snow melts seasonally - encircles the North Pole
-Only in Northern hemisphere
Permafrost
- Limits depth of root penetration (woody species)
little organic matter in soil
- Low temps
- Flat topography
- Bogs, ponds and low lakes in summer
Species characterised by low species richness and low growth rates

Question 7

What distinguishes an alpine tundra?

Answer 7

Similar to artic, but
No permafrost
More rain and wind that artic
Regenerates very slowly after disturbance

Question 8

What are the grasslands you know of? What separates them?

Answer 8

Tropical (Savannah)
Temperate
Temp

Question 9

What distinguishes grassland?

Answer 9

Average rainfall allows only grass to grow
rainfall low/erractic
fire or drought prevents larger plants from growing

Question 10

What distinguishes tropical grassland?

Answer 10

Scattered shrubs and stunted trees

• Year round high temps
• Low percipitation, dry and rainy periods
• Fire during dry season
  
  • animals migrate
  • plants have fire adapted features

Question 11

What distinguishes temperate grassland?

Answer 11

-Summers are hot, sry and have occasional drought and fires
-Winters are cold, rainfall uncertain (grass dies off)
-High winds, evaporation is rapid
-Soil held together with mats of roots
- Often ploughed
Overgrazing and mismanagement has led to desert

Question 12

What distinguishes a desert?

Answer 12

Deserts are dry areas - found both in temperate (cold deserts) and tropical regions (warm deserts)
- Cover 30% of the Earths land
• low rainfall main reason for deserts
• Generally receive < 25 cm rain per year
• Very fragile environment, slow regrowth
• evaporation is rapid
Low water vapour results in daily temperature extremes of heat and cold
Occur where dry air which has lost its moisture over the tropics drops back to earth
- Or in the middle of continents

Question 13

What distinguishes a tropical desert?

Answer 13

• commonly next to no life

- Few plants

Question 14

What distinguishes a temperate desert?

Answer 14

-Temperatures hot in summer cold in winter

Plants have evolved strats to capture and conserve water - waxy covering (cut downs evap rate), deep roots, reduced leaves

Question 15

What adaptations and behaviours do desert animals have to survive?

Answer 15

Escape heat in barrows
Have adaptations to conserver water

Reptiles have thick outer coverings
Minimise water loss
Some become dormant during extreme heat and drought

Question 16

What distinguishes a forest?

Answer 16

-Areas with moderate to hill rainfall usually cover with forest
- Smaller form of vegetation and various species of trees
Dependent on climate(temp)

Question 17

What distinguishes a tropical forest?

Answer 17

Found near equator where hot air rises and drops moistures
Has warm annual mean temp
Humid, heavy rainfall daily
Evergreen - etremely high growth

Question 18

Number and name the layers of a tropical forest…

Answer 18

• emergent layer
• canopy
• Understory
• Shrub
• Ground layer

Question 19

What sort of niches are found in tropical forests?

Answer 19

Narrow/specialised

Question 20

What kind of pollination must be used in tropical forests? Why?

Answer 20

Little Wind, therefore wind pollination impossible

-plants develop folowers that attract particular insects, birds, or bats

Question 21

Deciduous forests are distinguished by….

Answer 21

Moderate average temps that change significalantly during four seasons
Survive winter by dropping leaves
Few species than tropical forests
- More ground plants
Range of niches for animal life with more ground species and less specialised

Question 22

Name the layers of a deciduous forest…

Answer 22

• Canopy, partly open
  
  • Understory of shorter shade tolerant plants
    Forest floor with ferns, mosses and low growing plants

Question 23

What distinguishes an evergreen forest?

Answer 23

• Less common
  
  • Occcur with ample rainfall or moisture
    Mild temps

Question 24

Name the layers of an evergreen forest…

Answer 24

• Emergent
  
  • 30-50m tall trunks
  • Hardwood canopy
  • 20m Flowering trees, broad leaves
  • Subcanopy
  • 10-15m Wide assort of small and large trees
  • Shrub
  • Most carry defence against browsing
  • Floor
    Moist, dark

Question 25

What distinguishes a mangrove forest?

Answer 25

Grows in costal ecosystems

Question 26

Define a swamp…

Answer 26

Swamplike

Question 27

What is the fate of swamp?

Answer 27

• Can’t survive after germination due to drainage/dryland plants
  
  • Other species invading due to drainage
    Cut down for farmland, housing

Question 28

What defines a boreal forest

Answer 28

• Only in northern hemispher
  
  • Cold, long, dry short winter days (no permafrost)
  • Short summer, mild-warm temps, long days
  • Tiny needle shaped, wax covered leaves, able to withstand intense cold and drought of winer
  • Evergreen - allows photsynthesis to begin as soon as warm temps return
  • Two layers - long canopy and ground layer
  • Few species

Question 29

What are the deficits of a boreal forest?

Answer 29

• Not well suited to agriculture, short growing season
  
  • Forestry
  • Acid rain and air pollution
    Suceptible because slow growth