• Submitted By: Janice-Ng
• Date Submitted: 12/24/2015 1:46 AM
• Category: Science
• Words: 976
• Page: 4

Q1a: Define the term net primary productivity (NPP).
The gain in energy by producers after allowing respiration loss per unit area per unit time.

Q1b: Define the term gross secondary productivity (GSP).
The gain in energy by consumer by absorption per unit area per unit time.

Q1c: Calculate the efficiency of conversion of total insolation (sunlight) to NPP in Fig 5.
(37225/1700000) X100% = 2.2%

Q2: Explain the importance of soil organisms in ecosystems.
Soil organisms are free-living bacteria that fox atmospheric nitrogen converting into a usable and suitable form for plants roots.
They are decomposer that break down litter and release nutrients into oil.
They help to mix the soil, hence improving the structure of soil
The burrows of soil organisms help to aerate the soil
As thy decompose, they will contribute organic matter within the soil.

Q3: The enhanced greenhouse effect is predicted to lead to climate changes such as increased precipitation in some areas and decreased precipitation in other areas. Using Figure 4, predict the effect on nutrient cycling of increased precipitation over many years in a region that is currently a steppe.
The rate of leaching will increase
The rate of decomposition remains the same
The rate of uptake by plants increases

Q4: Explain the flow of energy through food webs.
Firstly, energy flow shows the pathway of energy through a system. The energy flow in the food web illustrate the first law of thermodynamics. Moreover, most incoming energy in food webs on Earth are from the Sun. And the outgoing energy for all food webs in the heat lost from respiration. Then, the energy transferred into decomposer food web through wastes and death

Q5: Define the terms gross primary productivity (GPP) and net primary productivity (NPP). Explain, with reference to two contrasting biomes, why one biome will be more productive than the other.
GPP is the total gain in energy by primary producers per...