Maintaining Terrestrial Biomes

• 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

Permitted activities include:

• logging

• mining

• oil and gas extraction

• livestock grazing

• farming

• recreation

• How should they be managed? Who should be permitted to use the lands? Ongoing controversy…

Examples:

• Northern Spotted Owl– Endangered species– Habitat: Old-growth forests

Of pacific northwest

Versus:

• Jobs and harvesting resources: the old-growth trees are of high commercial value

Should we “drill baby drill”???

ANWR

• 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)

Yosemite

The Grand Canyon

http://wallpaper-s.org/42_~_Claret_Cup_Cactus%2C_Grand_Canyon_National_Park%2C_Arizona.htm

Denali

Arches

Volcano

Carlsbad Caverns

Big Bend

Glacier

The Badlands

Great Smokey Mountains

• 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

• Second-growth: forest that has grown back after it had been cut/removed by human activities.

• 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

• Tree plantation or tree farm – Monoculture (example: Christmas tree farm)

• (example: apple orchard)

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.

• Strip cutting: removes all trees in an area in a single cutting (in a strip)

• 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

The catch??? Don’t harvest wild bamboo in Panda habitat!!

Types of Forest Fires

• Surface: Usually burn only undergrowth and leaf litter on forest floor.

• 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!

Prescribed burning:

• Controlled burning of flammable materials to prevent build-up.

Healthy Forests Initiative (HFI):

• Timber companies are allowed to cut down economically valuable large trees in return for clearing away fire-prone underbrush.

• Removes large, more fire-resistant trees.

• Leaves fire-prone slash: unwanted branches, tops, stumps.