Chapter 10 Sustaining Terrestrial Biodiversity: The Ecosystem Approach

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Chapter 10 Sustaining Terrestrial Biodiversity
The Ecosystem Approach
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Gray Wolf

• 1800-350,000 located lower 48 states especially
  west
• Preyed on bison, elk, caribou and mule deer
• 1850-1900 Most were shot, trapped, and poisoned
  by ranchers, hunters, and government employees
• Keystone species entered ESA list in 1974
• Wolves provided uneaten meat for scavengers
• Wolves controlled populations of bison, elk, and
  caribou
• Reintroducing grey wolves has helped re-establish
  and sustain biodiversity

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Forests Vary

• Old growth forest an uncut or regenerated
  primary forest that has not been seriously
  disturbed by human activities or natural
  disasters for 200 years or more
• Reservoirs of biodiversity because of ecological
  niches
• Second-growth forest a strand of trees
  resulting from secondary ecological succession
  develop after trees have been removed by humans

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Old Growth Forests in US state of Washingtons
Olympic National Forest
Old Growth Tropical Rainforest in Australia
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Forest Vary

• Tree plantation managed track of uniformly aged
  trees of one or two genetically uniform species
  that usually are harvested by clear cutting as
  soon as they become commercially valuable

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Price tags on Major Economical Services

• Some conservation biologists urge establishing
  tree plantations only on land that has already
  been cleared or degraded instead of putting them
  in place of existing old growth or secondary
  forests

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Major ecological services and economical services
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Whats the harm of building roads?

• Increases erosion and sediment runoff into
  waterways
• Habitat fragmentation
• Loss of biodiversity
• Opens area to farmers, miners, ranchers, hunters
  and off road vehicles to forest degradation

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Logging Roads
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Forest Cutting

• Selective cutting intermediate-aged or mature
  trees in an uneven-aged forest are cut singly or
  in small groups
• Strip cutting involves clear-cutting a strip of
  trees along the contour of land with in a
  corridor narrow enough to allow natural
  regeneration within a few years
• Clear cutting removing all trees from an area,
  most efficient way for a logging operation to
  harvest trees

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Selective, Clear and Strip Cutting
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Clear Cutting Forests
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Forest Fires

• Surface fires burns only undergrowth and leaf
  litter on the forest floor, kills seedlings and
  small trees but spares most mature trees and
  allow wild animals to escape
• Crown fires extremely hot fires that leaps from
  treetop to treetop, burning whole trees occur in
  forests that have not experienced surface fires
  in several decades

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Surface fire and Crown Fire
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Ecological benefits of Surface Fires

• Burn away flammable ground material help prevent
  more destructive fires
• Free valuable mineral nutrients tied up in slowly
  decaying material
• Release seeds from cones
• Stimulates germination of certain tree seeds
• Help control tree disease and insects

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Ways to prevent Disease and Insects

• Accidental or deliberate introduction of foreign
  diseases and insects are a major threat to
  forests
• Ban imported timber
• Remove or clear cut infested or infected trees
• Develop tree species genetically resistant to
  common disease
• Apply conventional pesticides
• Biological control (bugs that eat harmful bugs)

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Nonnative insect species and disease organisms
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Global Warming

• Climate change from global warming could harm
  forests
• Sugar maples are heat sensitive, a change in
  climate could kills these trees thus kill the
  maple syrup industry
• Rising temperatures will cause insects
  populations to rise
• Because of drier temperatures, forest will be
  more susceptible to forest fires
• More CO2,will lead to more warming which will
  lead to more forest loss

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Where are forest losses the greatest?

• Developing countries are experiencing greatest
  loss especially tropical areas Latin America,
  Indonesia, and Africa
• 50,000 sq miles cleared each year
• Loss Boreal forest of Alaska, Canada,
  Scandinavian, and Russia
• Makes up 1/4 of worlds forested area
• Worlds greatest terrestrial storehouse of
  organic carbon/ plays a major role in carbon cycle

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Extreme tropical deforestation in Thailand,
increases global warming
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Deforestation

• The temporary or permanent removal of large
  expanses of forest for agriculture, settlements,
  or other uses

Harmful effects of deforestation
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US in Recovery

• Every year, more wood is grown in the US than is
  cut and the total area planted with trees
  increases
• Protected forests make up about 40 of the
  countrys total forest area, mostly in the
  National Forest System, which consists of 155
  national forests managed by the US Forest Services

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Major causes of Deforestation
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Manage Forests
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Certifies timber

• Timber that is selectively cut and sold by a
  nonprofit Forest Stewardship Council

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Ways to reduce harms of Forest Fires

• Set small contained surface fires to remove
  flammable small trees and underbrush
• Allow fires on public lands to burn and thereby
  remove flammable underbrush and smaller trees
• Protecting houses and other buildings in
  fire-prone areas by thinning a zone of about 60
  meters
• Thin forest areas vulnerable to fire by clearing
  away small fire-prone trees and underbrush under
  careful environmental controls

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Harvested Trees

• Up to 60 of the wood consumed in the United
  States is wasted unnecessarily
• Inefficient use of construction material, excess
  packaging, overuse of junk mail, in adequate
  paper recycling, and failure to reuse wooden
  shipping containers

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Fuel wood Crisis

• Fuel wood is used by developing countries for
  heating and cooking by more than 2 billion people
• Reducing establish small plantations of fast
  growing fuel wood trees and shrubs
• Villagers can switch to burning the renewable
  sun-dried roots of various gourds and squash
  plants
• Scientists are also looking for ways to produce
  charcoal for heating and cooking without cutting
  down trees

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Green Belt Movement

• Wangari Maathai began the Green Belt Movement in
  1977 in her backyard with a small tree nursery
• Organize poor women in rural Kenya to plant and
  protect millions of tees in order to combat
  deforestation and provide fuel wood
• By 2004, 50,000 members in 6,000 villages have
  planted and protected 30 million trees

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Protecting Tropical Rainforests
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Rangeland Overgrazed

• Rangelands unfenced grasslands in temperate and
  tropical climates that supply forage, or
  vegetation, for grazing (grass-eating) and
  browsing (shrub-eating) animals
• Cattle, sheep and goats graze on 42 of the
  worlds grasslands
• Expected to be 70 by 2050
• Livestock graze on pastures managed grassland
  or enclosed meadows usually planted with
  domesticated grasses or other forage

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Overgrazing and Undergrazing

• Overgrazing when too many animals graze for too
  long and exceed the carrying capacity of a
  rangeland area
• Reduces grass cover, exposes soil to erosion, and
  compacts the soil (which diminishes the capacity
  to hold water)
• Natural grassland ecosystems were maintained
  partially by periodic wildfires sparked by
  lightning
• Some grasslands suffer from undergrazing, where
  the absence of grazing for long periods (at least
  5 years) can reduce the net primary productivity
  of grassland vegetation and grass cover

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Sustaining Rangelands

• Widely used method is controlling the number of
  grazing animals and the duration of their grazing
  in a given area (3 ways)
• Rotational grazing cattle are confined by a
  portable fence for 1-2 days and then moved to
  another area
• Fencing off riparian zones (lush vegetation near
  water sources)
• Use of herbicides, mechanical removal or
  controlled burning helps control invader species
• Replanting barren areas with native seeds and
  applying fertilizers can increase growth of
  desirable vegetation and reduce soil erosion

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Cattle overgrazing of a stream
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Ranchers and Urban Development

• Housing developments are slowly creeping into
  rangelands of the southwester US
• Environmentalist have been working with farmers
  to reduce overgrazing, now they have to compete
  with developers for the natural land
• One strategy is Conservation easements with
  ranchers deed restrictions that bar future
  owners from developing the land

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Threats to National Parks

• Too small to sustain a lot of large animal
  species
• Invasion of nonnative species that compete with
  and reduce the populations of native species
• Parks of developing countries are not protected
• Illegal mining and logging, poaching occur in
  these parks

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US Public Parks

• Established in 1912, includes 58 major national
  parks
• One of the biggest problems is popularity
• Noise and pollution from motor and recreational
  vehicles degrade the parks
• Parks suffer damage from migrating or deliberate
  induction of invasive species
• Polluted air and human activities are threatening
  wildlife

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Solutions to Parks
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Nature Reserves

• Currently, only 12 of the earths land area is
  protected strictly or partially in nature
  reserves, parks, wildlife refuges, wilderness,
  and other areas
• 12 is misleading because no more than 5 of the
  earths land is strictly protected from
  potentially harmful human activities
• We have reserved 95 of the earths land surface
  for human use
• Conservation biologists call for full protection
  of at least 20 the earths land area in global
  system of biodiversity reserves that would
  include multiple examples of all earths biomes

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Buffer Zones for Nature Reserves

• Research indicates that in other locales, several
  well-placed, medium sized reserves may better
  protect a wider variety of habitats and preserve
  more biodiversity than would a single large
  reserve of the same total area
• Buffer Zones this means protecting an inner
  core of a reserve by usually establishing two
  buffer zones in which local people can extract
  resources sustainably without harming the inner
  core
• This approach enlists local people as partners in
  protecting a reserve from unsustainable uses such
  as illegal logging and poaching

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Buffer Zone Design (Biological Reserve)
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Costa Ricas Nature Reserves

• Costa Rica has consolidated its parks and
  reserves into eight zoned megareserves designed
  to sustain about 80 of the countrys rich
  biodiversity
• Green areas are protected
• Reserves and yellow areas are
• Nearby buffer zones, which can
• Be used for sustainable forms of
• Forestry, agriculture, hydropower
• hunting, and other human
• activities

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Wilderness

• Legally setting aside large areas undeveloped
  land
• Preserving biodiversity as a vital part of the
  earths natural capital
• Protect wilderness areas as centers for evolution
  in response to mostly unpredictable changes in
  environmental conditions
• Wilderness serves as a biodiversity bank and an
  eco-insurance policy

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Controversy over Wilderness

• Conservationists have been trying to save wild
  areas from development since 1900
• 1964 Congress pass the Wilderness Act
• This act protect less than 2 of US wilderness
• Roadless rules have protected wilderness areas 20
  years
• 2005, secretary of interior ended this protection
  of roadless areas with in the national forest
  systems

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Biodiversity Hotspots

• Areas especially rich in plant species that are
  found nowhere else and are in great danger of
  extinction
• Suffer serious ecological disruptions mostly
  because of rapid human population growth and the
  resulting pressure on natural resources
• Save biodiversity of the planet by protecting
  these areas

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Ecological Restoration

• The process of repairing damage caused by humans
  to the biodiversity and dynamics of natural
  ecosystems
• Restoration returning a particular degraded
  habitat or ecosystem to a condition as similar as
  possible to it natural state
• Rehabilitation turning a degraded ecosystem into
  a functional or useful ecosystem without trying
  to restore it to its original condition

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Ecological Restoration

• Replacement replacing a degraded ecosystem with
  another type of ecosystem
• Creating artificial ecosystems

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Strategies for Restoration

• Identify what caused the degradation
• Stop the abuse by eliminating or sharply reducing
  these factors This would include removing toxic
  soil pollutants, adding nutrients to depleted
  soil, adding new topsoil, preventing fires, and
  controlling or eliminating disruptive nonnative
  species
• Reintroduce species especially pioneer,
  keystone, and foundation species
• Protect the area from further degradation

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Tropical Dry Forest of Costa Rica

• A small tropical dry forest was burned, degraded,
  and fragmented by large-scale conversion to
  cattle ranches and farms
• One of the worlds largest restoration project
• Goal is to eliminate damaging nonnative grasses
  and reestablish a tropical dry forest ecosystem
  over the next 100-300 years

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Reconciliation or applied ecology

• This science focuses on inventing, establishing,
  and maintaining new habitats to conserve species
  diversity in places where people live, work, or
  play
• We need to share with other species some of the
  spaces we dominate
• Community based conservation scientists,
  citizens, government work together to preserve
  biodiversity

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