Forest Ecosystem Function Introduction

Question 1

Use of Carbon

Answer 1

Half to build tissue, other half to fuel cellular processes (converted back into CO2)

Question 2

What is biomass ?

Answer 2

(standing crop) weight of organic material per area at a given point in time…..represents stored energy

Question 3

What is production ?

Answer 3

amount of biomass (energy) produced in an area over a certain time period

Question 4

What is productivity ?

Answer 4

production per unit area per unit of time, it’s a RATE

Question 5

What is gross production ?

Answer 5

total biomass (energy or carbon)

Question 6

Net production ?

Answer 6

gross production - losses to respiration

Question 7

Primary production ?

Answer 7

energy captured by primary producers (autotrophs)

Question 8

Secondary, tertiary production ?

Answer 8

energy into consumers, detritivores

Question 9

Gross Primary Production ?

Answer 9

Total Production of carbon by 1st producers (= all carbon produced by photosynthesis in a forest)

Question 10

Net Primary Production (NPP) ?

Answer 10

Gross Primary Production (GPP) - autotrophic respiration (respiration of all plants)

Question 11

Net Ecosystem Production (NEP) ?

Answer 11

NPP - Heterotrphic Respiration (RH) (respiration of all-non autotrophs)

Question 12

Why is Carbon important ?

Answer 12

• energy currency of all ecosystems
  –> plant (autotrophic) production is the base of almost all food/trophic webs
  –> underlies all ecosystem goods and services
• plant C cycling, controls atmospheric CO2 concentrations
  –> 3 to 4 times as much in terrestrial ecosystems as the atmosphere
  –> forests account for 80% of global plant biomass and 50% of global terrestrial productivity
• C is fundamental to soil processes
  –> Belowground resources are a primary control over all ecosystem ecosystems (SOM : biological, physical and chemical functions).

Question 13

Importance of soils for carbon storage ?

Answer 13

Soils store the most terrestrial organic C.

Question 14

Central concepts for understanding C cycling in ecocystems ?

Answer 14

1. Pools (storage) vs fluxes (flows) of C
   –> LIve and dead (detrital biomass)
   –> Above and belowground
2. Law of conservation of Mass

Question 15

Relation between inputs, outputs and storage ?

Answer 15

Inputs = Outputs + Difference of storage

Question 16

Major forest carbon pools ?

Answer 16

1. Live aboveground
   –> Shrubs
   –> Trees
   –> Other plants
2. Live belowground
   –> Roots
3. Deadwood
   –> Standing dead trees (snags)
   –> Downdd logs
4. Litter
   –> Leaves
   –> Needles
   –> Small branches
5. Soil organic matter
   –> dead and decayed biomass
   –> plant material and insects

Question 17

Factors influencing the amount and proportion of carbon in each forest carbon pools ?

Answer 17

• Age of the forest
• Species of trees making the forest
• Natural and human disturbances
• Soil characteristics (texture and drainage)
• Past agricultural land-use history

Question 18

Size of C pools in different forests ?

Answer 18

High storage in aboveground pool in tropical forests (mostly moist and wet), not a lot in boreal dry.
High storage in belowground pool in boreal moist.

Question 19

Type of autotrophs (self-feeding) ?

Answer 19

Photoautotrophs: sun energy converted into sugars, higher plants, algae
Chemoautotrophs: sulfur, iron, hydrogen bacteria; nitrifying bacteria.

Question 20

Heterotrophs ?

Answer 20

Use organic sources of carbon/energy
Consumers: primary (herbivores), secondary/tertiary (omnivores, carnivores), Detritivores (saprotrophs).

Question 21

Principle of photosynthesis ?

Answer 21

Energy storing. In chloroplast.
Requires CO2 (carbon dioxide) and water, produces sugar and oxygen.
PAR = photosynthetically active radiation of sunlight.
Transfer of energy/matter from inorganic carbon (CO2 gas) to organic carbon (glucose)

Question 22

Principle of aerobic respiration ?

Answer 22

releases energy. in mitochondria
Requires oxygen and glucose, releases CO2 and ATP (energy) and heat. Breakdowns of sugars to provide energy.

Question 23

What is production ecology ?

Answer 23

study of energy transfers and storage in the ecosystem.
- complex carbon molecules store energy in their bonds
- C constitutes about 50% of dry mass of all organisms
- carbon is the currency
- energy stored or transferred often expressed in biomass units.

Question 24

What are the inputs, the transfers within the ecosystem and the outputs?

Answer 24

inputs : autotrophs
transfers within the ecosystem : trophic web to dead organic matter (DOM)
outputs : respiration