1. Forestry
Miller—Chapter 23

2. Major Types of Forests
Tropical
Subtropical
Temperate
Polar (boreal)

3. Purpose of Forests Support energy flow and chemical cycling
Ecological Services
Economic Services
Support energy flow and chemical cycling
Reduce soil erosion
Absorb and release water
Purify water
Purify air
Influence local and regional climate
Store atmospheric carbon
Provide numerous wildlife habits
Fuelwood
Lumber
Pulp to make paper
Mining
Livestock grazing
Recreation
Jobs

4. Forests
Old-growth forests (frontier forests): uncut or regenerated forests that have NOT been disturbed by human activities or natural disasters for at least several hundred years
Provide ecological niches for a multitude of wildlife species
Second-growth forests: resulting in secondary ecological succession after the trees in an area have been removed by
1) Human activities such as clear-cutting for timber or conversion to cropland
2) Natural forces such as fire, hurricanes, or volcanic eruption
Tree plantation (tree farms): Managed tracts with uniformly aged trees of one species that are harvested by clear-cutting as soon as they become commercially valuable. Then they are replanted and clear-cut again on regular cycles. Cover 5% of world’s tree cover, provide 10% of wood

5. Types of Forests

6. Types of Forest Management
As the forest goes through different stages, the total volume of wood produced by a particular stand of forest varies as it goes through different stages of growth and ecological succession.
Have to figure out the best way to produce fuelwood or fiber for paper production in the shortest time using a short rotation cycle
Type of management depends on economy
Even-aged management: Maintain trees in a given stand the same age and size. Like a small tree plantation, a old-growth or second-growth forest is replaced with 1-2 types of fast growing trees that can be harvested every years.
Uneven-aged management: Maintaining a variety of tree species in a stand at many ages and heights to foster natural regeneration. Prioritizes biological diversity, sustainability, selective cutting methods, multiple uses for forests (usually longer term)

7. Types of Forests

8. Problems associated with logging:
Increased erosion and sediment runoff into waterways
Habitat fragmentation and biodiversity loss
Exposure of forests to invasion by nonnative pests, diseases, and wildlife species
Opening of once-inaccessible forests to farmers, miners, ranchers, hunters and ORV users.
If you log, can’t protect land and make it public wilderness

9. Harvesting Methods Selective Cutting Shelterwood Cutting
Intermediate-aged or mature trees in an uneven-aged forest are cut singly or in small groups
Reduces crowding, removes diseased trees
Encourages growth of younger trees
Maintains an uneven-aged stand of trees of different species
Allow natural regeneration from surrounding trees
Can help with soil erosion problems/wind damage
Multi-purpose uses for forests
For trees that grow best in full-to-moderate sunlight in medium to large sized clearings
Removes all mature trees in 2-3 cuttings over a period of about 10 years

10. Harvesting Methods Seed-tree cutting Clear-cutting
For trees that grow best in full-to-moderate sunlight in medium to large sized clearings
Harvests nearly all a stand’s trees in one cutting, leaving a few uniformly distributed seed-producing trees to regenerate the stand
For trees that grow best in full-to-moderate sunlight in medium to large sized clearings
Removes all trees from an area in a single cutting
Can be strip-cutting
Increases timber yield per hectare
Permits reforesting with genetically improved, fast-growing trees
Shortens time needed to establish a new stand of trees
Takes less skill and planning
Max. economic return in shortest time

11. Types of Harvesting

12. Issues in Forestry Need for more sustainable growing
Long rotations of years, using selective/strip cutting, reduce road blocks, minimize fragmentation, reduce soil erosion, leave boles and snag for wildlife diversity, use tree plantations
Must reduce impact of tree diseases from pathogens and insects
Ban imported wood, remove/clear-cut infected species, develop disease-resistant trees, apply pesticides, IPM
Forest fires
Prevention, prescribed burning, presuppression, suppression, be aware of impact from climate change