maintaining terrestrial biomes. in the united states, the government manages public lands including...
TRANSCRIPT
• In the United States, the government manages public lands including forests, parks, and refuges.
• Their use varies from resource extraction to farming to recreation.
• Multiple use lands include those in the
– National Forest System• Managed by the U.S. Forest Service
– National Resource Lands• Managed by the Bureau of Land
Management– National Wildlife Refuges
• Managed by the U.S. Fish and Wildlife Service
Examples:
• Northern Spotted Owl– Endangered species– Habitat: Old-growth forests
Of pacific northwest
• Some public lands are restricted in use– National Park System
• Managed by the National Park Service (NPS)
• First established National Park??? – Only camping, hiking, fishing, and boating
(motorized cars/boats are allowed)
• Other public lands are very restricted – meant to be preserved in their natural condition– National Wilderness Preservation System
• Established by the Wilderness Act (1964)• Managed by multiple agencies (BLM,
USFWS, USFS, and NPS)– National Wild and Scenic Rivers (1968)– Non-motorized recreation ONLY
Types of Forests:
• Old-growth: has not been cut/disturbed by human activity for hundreds of years.– Example: Redwood
Forest
• Since 1600, 90% of the virgin forests that once covered much of the lower 48 states have been cleared away. Most of the remaining old-growth forests in the lower 48 states and Alaska are on public lands. In the Pacific Northwest about 80% of this forestland is slated for logging.
– Global Deforestation Lecture, The University of Michigan: Global Change
Types of Forest Management:
• Even-aged: Maintaining trees at about the same age and size (tree plantation)– Goal: economically desirable species
• Uneven-aged: Maintaining a variety of trees at many ages and sizes– Goal: sustainable production
Types of Tree Harvesting:• Selective cutting: medium or mature trees
in uneven-aged stand cut singly or in small groups.
• Shelterwood cutting: remove all mature trees in an area in a series of cuttings.
– First cut: mature trees (mostly canopy trees)– Second cut: more mature canopy trees but
leaves a few mature trees to “shelter” the young trees (which are shade tolerant)
– Third cut: remove remaining mature trees now that the younger ones are growing to maturity
• Seed-tree cutting: harvesting nearly all trees in one cutting, but leaving a few uniformly distributed seedlings.
• Clear cutting: removes ALL trees in a single area. MOST devastating to an ecosystem; causes massive soil erosion if done on sloped land.
Alternatives...
• Do we HAVE TO cut down trees? Or can we use another resource…– Kenaf: rope, cloth, paper
– Hemp: cloth, paper, fuel
• The Neem Tree– Pharmaceuticals– Birth control– Fuelwood– Lumber– Infection-fighter– Spermicide– Insect repellent– Gives more O2– Grows FAST
• Bamboo– Grows FAST!! (24 hr time lapse video)– No pesticides! No fertilizers! No irrigation! No
replanting!– Absorbs more than twice the CO2 as trees!– Alternative to hardwood floors
• Ground: surface fire that goes underground (most common in areas that contain peat – northern peat bogs). Difficult to detect and extinguish.
(peat bog)
• Crown: May start on ground but eventually burn up whole tree and leap tree-top to tree-top.
• MOST DANGEROUS!