Forestry and Agriculture

Question 1

Two basic processes for the flow of energy

Cycling of chemical elements

Answer 1

Solar energy
Cultural energy - energy use in the production of food and other products

Water, carbon, essential elements (nitrogen)

Question 2

Limiting factors principle

Answer 2

Too little or too much of any abiotic factor limits or prevents growth of a population, even if all other factors are near the optimum.

Question 3

What is the Haber Bosch process and how is it important

Answer 3

An industrial process for producing ammonia from nitrogen and hydrogen, using an iron catalyst at high temperature and pressure.
It is estimated that at least 2 billion people are alive today because of the proteins in their bodies are built with nitrogen that came via plant and animal foods from a factory using the hater bosch process.
- we have doubled the rate of nitrogen input into the terrestrial N cycle in less than 100 years

Question 4

Why are there different forms of forestry and agriculture in different places

Answer 4

• Differences in climate
• Differences in land attributes
• Differences in socio-economic factors

Question 5

Biomes

Answer 5

terrestrial regions with characteristic types of natural, undisturbed plant communities adapted to the climate of the area, influenced by temperature and rainfall

Question 6

Planetary Boundaries

Answer 6

boundaries designed to avoid the crossing of a critical threshold in an earths system process.

Question 7

2 categories of tropical rainforests and their characteristics

Answer 7

Tropical rainforest- high rainfall, little limitation to growth through water stress
Deciduous- wet/ dry season, trees lose leaves as a strategy to cope with dry weather

Question 8

2 categories of temperate rainforests and their categories

Answer 8

• temperate deciduous rainforest

- temperate rainforest

Question 9

Boreal (polar forests) and characteristics

Answer 9

• large rea with limited number of species, soil is frozen, adapted the growth in cool environment

Question 10

What is a biome

Answer 10

terrestrial region with characteristic type of natural, undisturbed plant communities adapted to the climate of the area- influenced by temperature and rainfall

Question 11

What are some ecological processes occurring in forests

Answer 11

water movement, water use by trees, nutrient cycling, light interception and utilisation, seed dispersal, germination, growth, succession

Question 12

Systems of classification of forests

Answer 12

tree height, distance between trees, species diversity

Question 13

What are some uses of forested lands

Answer 13

wilderness value, water catchment, recreation, wood products, land cleared for crops and animals

Question 14

Why are native forests used instead of plantations

Answer 14

Selective cutting
Shelterwood cutting
Seed-tree cutting
Clear felling

Question 15

Selective cutting - advantages and disadvantages

Answer 15

• Cutting down of selected trees in a forest so that growth of other trees is not affected
  Advantages
  intermediate age or mature trees cut singly or in small groups
  Growth of young trees encouraged by decreased crowding
  Soil protected from erosion
  Disadvantages
  Not profitable- high cost of removing only a small portion of trees
  High grading

Question 16

Shelterwood cutting- advantages and disadvantages

Answer 16

• Progression of forest cuttings leading to the establishment of a new generation of seedlings. Implemented in forests that are considered mature
• removes all trees over a 2-3 year period
  leaves enough mature trees for seeding- allows best trees to be left to produce seeds

Question 17

Seed-tree cutting- advantages and disadvantages

Answer 17

• Removing all trees from a stand and leaving only a few trees behind to produce seeds for regeneration of an even ged forest - used for regenerating trees that grow well in direct sunlight
• harvest nearly all trees in one cutting, leaving a few seed trees

Question 18

Clear felling- advantages and disadvantages

Answer 18

- the removal of all trees in an area in a single cutting chosen for harvesting (logging) - called a coupe 
Advantages
- most simple approach 
- efficient and highly profitable 
Disadvantages
- sudden loss of forest ecosystems 
- changes hydrogeloly 
- loss of biodiversity 
- increase weeds 
- decrease in organic carbon + nutrients

Question 19

Impacts of deforestation

Answer 19

• change in hydrology - flooding, siltation, salinity

- greenhous gas emissions- burning of vegetation, decreased organic carbon in soil

Question 20

Where is the primary source of timber products and why does illegal export occur and what are the impacts

Answer 20

South east Asia is the primary source of timber production.
Illegal export occurs as a result of corruptionn, - nt having to pay royalties
- impacts, loss of income, over exploitation of forests, high grading, export as round logs