1.8 - Primal Productivity

Question 1

What is the unit for Primary Productivity?

Answer 1

kcal/m^2/yr

Question 2

What is primary productivity (PP)?

Answer 2

• rate that solar energy is converted into org. compounds via photosynthesis over a unit of time
• rate of photosynthesis of all producers in an area over a given period of time
• the amount of plant growth in an area over a given period of time

Question 3

What does high PP mean?

Answer 3

• high plant growth, which leads to lots of food and shelter for animals

Question 4

What does it mean when an ecosystem has a high PP?

Answer 4

• ecosystems with high PP are usually more biodiverse than ecosystems with low PP

Question 5

What is the formula for calculating PP

Answer 5

Net Primary Productivity = Gross Primary Productivity - Respiration Loss

Question 6

What is Net Primary Productivity (NPP)?

Answer 6

The amount of energy (biomass) leftover for consumers after plants have used some for respiration

Question 7

What is Gross Primary Productivity (GPP)?

Answer 7

The total amount of sun energy (light) that plants capture and convert to energy (glucose) through photosynthesis

Question 8

What is Respiration Loss (RL)?

Answer 8

plants use up some of the energy they generate via photosynthesis by doing cell. respiration (movement, internal transportation, etc.)

Question 9

Explain Ecological Effeciency

Answer 9

• The portion of incoming solar energy that is captured by plants & converted into biomass (NPP or food available for consumers)
• Generally, only 1% of all incoming sunlight is captured & converted into GPP via photosynthesis
• Of that 1%, only about 40% (or 0.4% of total incoming solar energy) is converted into biomass/plant growth (NPP)

Question 10

T or F
All ecosystems are the same, none of them are more efficient than others

Answer 10

False
Some ecosystems are more efficient (higher NPP) than others

Question 11

Trends in productivity

Answer 11

• The more productive a biome is, the wider the diversity of animal life it can support (high. biodiv.)
• Water availability, higher temperature, and nutrient availability are all factors that lead to high NPP

Question 12

What three things lead to higher NPP

Answer 12

1. Water availability
2. higher temperature
3. nutrient availability

Question 13

What factors lead to a decreased NPP

Answer 13

1. Desert (low H2O and nutrients)
2. Tundra (low temp and liquid H2O)
3. Open Ocean (low nutrients)

Question 14

Percentages for Ecological Efficiency

Answer 14

• 99% - solar energy is reflected or passed through producers without being absorbed
• 1% - solar energy striking producers is captured by photosynthesis (GPP)
  - 60% - lost GPP to respiration
  - 40% of GPP supports the growth and reproduction of producers (NPP)