Exam 2

Question 1

GPP

Answer 1

Gross primary productivity

NPP+r

Question 2

NEP

Answer 2

Net Ecosystem Productivity
GPP- r(plants)-r(consumers)-r(decomposers)

Tells whether a forest is a carbon source or sink

Question 3

What’s more productive a tropical rain forest a a temperate forest or the open ocean? Tropical versus woodlands and grasslands?

Answer 3

Tropical rain forest is 50% more productive than a temperate forest but not as productive as the open ocean.

3-5x as productive as woodlands and grasslands

Question 4

How much of the GPP of a rainforest is respirated?

Answer 4

50-60%

Question 5

Terrestrial ecosystem model

Answer 5

Uses five components

• carbon in veg
• carbon in soils and detritus
• N in veg
• N in soils and detritus
• available inorganic soil N

Other variables

• temp
• cloudiness
• elevation
• precip
• soil texture
• veg type

Question 6

What is a carbon sink?

Answer 6

More sequestration less respiration

Question 7

Leaf area index (LAI)

Answer 7

The lead area above a square meter of forest floor.

High in the tropics

Question 8

Water use efficiency

Answer 8

Ratio of water used in plant metabolism to water lost via transpiration

Question 9

Diffuse radiation (solar dimming)

Answer 9

Increased light use efficiency due to increasing fraction of diffuse light (dust, aerosols)

May reduce c losses via photorespiration (temp stress)

Wet tropics benefit greatly

Question 10

Disturbance recovery hypothesis

Answer 10

Lighter wooded species decline and heavier wooded species increases proportionately with succession

Question 11

Resource availability hypothesis

Answer 11

No relationship between C stocks and wood density

Question 12

Effects of deforestation on climate

Answer 12

Temperature increase in the tropics by 2 Celsius and drier air above tropics and drought in northwest America

Question 13

Increased temp effects

Answer 13

Higher tree mortality

Question 14

Theory of island biogeography

Answer 14

With time areas or islands will attain dynamic equilibrium

Question 15

How is Chagas’ disease being effected by fragmentation

Answer 15

Lives in palm oil trees

More palms =more bugs that are infected = more people with the disease

Question 16

How is soil formed?

Answer 16

P-parent material
C-climate
O-organisms
R-topography
T-time

Question 17

Role of n and p in tropical soils

Answer 17

N is limiting in temperate and high latitude

P is limiting in lowland tropics
N constrains growth due to high P in montane tropical forests

Question 18

Grazing and fire on North American vs South African Savannah

Answer 18

SA has more history with fire and grazing also larger herbivores affecting the grassland in different ways than that of a NA grassland

Question 19

NPP

Answer 19

Net primary productivity

GPP-r(plants)