Chapter 23 Sustaining Terrestrial Biodiversity: The Ecosystem Approach

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Chapter 23 Sustaining Terrestrial Biodiversity
The Ecosystem Approach
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Key Concepts

• Human land use

• Types and uses of US public lands

• Forests and forest management

• Implications of deforestation

• Management of parks

• Establishment and management of nature preserves

• Importance of ecological restoration

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Land Use in the World
39 of the land is directly used by humans
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Land Use in the United States
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Types of US Public Lands

• Multiple-use lands 155 National Forests
• i.e. mining, logging, livestock grazing,
  recreation, hunting
• conservation of watershed

• Moderately-restricted use lands
• 522 National Wildlife Refuges
• i.e. protected habitats, and breeding ground
  for waterfowl, big game for hunting, mining,
  logging, oil gas development etc.

• Restricted-use lands 379 National Park System
  630 National Wilderness Preservation System
• i.e. protected areas, oil gas drilling,
  camping, hiking, fishing, hunting etc.

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US Public Lands
National forests, national parks, wildlife
refuges managed by US fed. Gov.
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How to Manage US Public Land?

• Protecting biodiversity and ecological function
• should be the main goal

• No subsidies or tax breaks for using or
• extracting resources (as in the past i.e. for
  mining, logging etc.)

• Public should get fair compensation for the use
• of their property

• Users should held responsible for any
• environmental damages

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Managing and Sustaining Forests
Ecological Importance of Forests

• Food webs and energy flow

• Water regulation, preventing erosion

• Local and regional climate

• Numerous habitats and niches

• Air purification

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Forest Structure
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Managing and Sustaining Forests
Economic Importance of Forests

• Fuelwood (50 of global forest use, sustainable?)

• Industrial timber lumber (30)

• Pulp and paper (20)

• Medicines

• Mineral extraction, livestock grazing recreation

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Types of Forest Biomes determined by Climate

• Old-growth forests not cut or disturbed

• Second-growth forests previously harvested or
• naturally disturbed

• Tree farms/plantation industrialized monoculture

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Types of Forest Management
Forests as renewable resources

• Rotation cycle

• Even-aged management

• Industrial forestry

• Uneven-aged management

• Improved diversity

• Sustainable production

• Multiple-use

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Management Strategies
Short rotation cycle of cutting regrowth
of monoculture tree plantain
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Negative effects of Logging Roads
Roads are needed before economical harvesting
is possible

• Increased erosion and runoff

-destruction, -fragmentation, -degradation
i.e. overgrazing, erosion, exotic species

• Habitat fragmentation

• Pathways for exotic species

• Accessibility to humans

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Harvesting Trees

• Selective cutting
• Individual trees are selected

• Shelterwood cutting
• removal of mature trees in
• several cycles, seed resource

Cut 2
Cut 1
Selective Cutting
Shelterwood Cutting

• Seed-tree cutting
• leaving seed resources

• Clearcutting
• just brutal

Seed-Tee Cutting
Clear-Cutting

• Strip cutting
• Allows natural generation
• to occur

Uncut
Cut
Cut
Cut
Uncut
1 year ago
35 years ago
610 years ago
Strip Cutting
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Sustainable Forestry

• Longer rotations growth more timber

• Selective or strip cutting has the lowest
  negative impact

• Minimize fragmentation leave larger blocks of
  forest

• Improved road building techniques to minimize
  erosion

• Certified sustainable grown independent
  organizations

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Pathogens affect harvest rates particularly in
monocultures
Fungal Diseases (many exotic species)

• Chestnut blight (from China)

• Dutch elm disease (from Europe)

Insect Pests

• Bark beetles (several species from Asia etc.)

• Gypsy moth (from Europe)

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Effects of Fire on the Forest
Fire as a natural disturbance can play a vital
role in the maintenance of habitats. For example
in the Everglades were it maintains Pinelands by
killing Hammock species.
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Effects of Fire on the Forest
Surface fire burns mostly undergrowth and leaf
litter on forest floor. May kill seeds or trigger
germination i.e. Sequoia. Crown fire extreme hot
fire kills most of the vegetations
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Pineland Hammock
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Forest Resources and Management in the United
States
Forest covers over 30 of the US,
provides habitat for more than 80 of the
countrys species.

• Habitat for threatened and endangered species

• Water purification services

• Recreation

• 3 of timber harvest

• Sustainable yield and multiple use

• Substitues for tree products

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Tropical Deforestation
Tropical forests cover only 6 of the earths
land mass. Tropical forests provides habitat for
more than 90 of the worlds species. Over 90 of
the worlds forest loss is occurring in tropical
countries. Currently less than 5 of the worlds
tropical forests are protected as parks, well
then there are Paper Parks.

• Rapid and increasing deforestation
• By 2042 over 50 of the species will be extinct
  if the current rate of deforestation continues.
• Lost forests Brazil 40, Haiti 99, Philippines
  97, Madagascar 84

• Loss of biodiversity many species are still
  unknown, occupy
• highly specialist niches, that makes them
  vulnerable to extinction.
• Forests are crucial for world climate, uptake of
  CO2 etc.

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Tropical Deforestation

• Cultural extinction Over 250 million people
  belong to
• indigenous cultures and used tropical forest
  products in a sustainable
• way. Many native communities are vanishing as
  the lands they
• lived on are taken over for cheap economical
  developments.
• We are losing our cultural and intellectual
  diversity.

• Unsustainable agriculture and ranching Meat
  demand
• from Developed Counties sometimes even
  subsidies by
• governments, leads to overgrazing erosion.
  Poor people from
• the cities migrate into tropical forests and
  practice unsustainable
• agriculture that leads to erosion, depletes soil
  etc..

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Tropical Deforestation

• Clearing for cash crop plantations Large
  plantation grow
• crop such as bananas, sugarcane, pineapples,
  peppers, coffee, cotton,
• tea to fulfill our culinary desires.
• Fertilizer, Pesticides (incl. DDT), water waste,
  erosion, air,
• soil water pollution, depletion of soils, did
  I forget anything?

• Commercial logging, mining, oil explorations etc.
  
• Provides infrastructure i.e. streets and higher
  demand for forest
• resources.

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Degradation of Tropical Forests
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Reducing Tropical Deforestation

• Identification of critical ecosystems Hotspots

• Reducing poverty and population growth

• Sustainable tropical agriculture

• Encourage protection of large tracts

• Less destructive harvesting methods

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Managing and Sustaining National Parks

• Most parks are too small to maintain biodiversity

• Invasion by exotic species

• Popularity a major problem

• Traffic jams and air pollution

• Visitor impact (noise)

• Natural regulation

• Better pay for park staff

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Establishing, Designing, Managing Nature
Reserves

• Include some moderate disturbance, treefall,
  wildfire

• Sustain natural ecological processes

• Protect most important areas

• Buffer zones

• Wilderness areas

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Ecological Restoration

• Ecological restoration restore a degraded
  habitat or
• ecosystem.

• Restoration ecology research devoted to
  restoring,
• repairing reconstructing of damages systems.

• Creating artificial ecosystems

• Natural restoration by identifying protecting
  key plant
• species and allowing natural ecological
  succession.
• For example, plants along sand dunes on beaches.