GEOG 3000 Resource Management Forest Resources'

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GEOG 3000 Resource ManagementForest Resources.

• M.D. Lee CSU Hayward Winter 2004

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A Declining Asset

• Forests, as ecosystems and resource stores, can
  yield a broad range of goods and services, both
  extractive and intrinsic but often we dont see
  the forest for the trees.
• However, as indicated with respect to global
  warming, world forest cover has shrunk by 50
  with industrialization and population growth and
  many millions of acres have been fragmented or
  degraded.
• How have we managed and valued forests in the
  past to bring us to this situation?
• Why has so much forest cover been lost and what
  are current trends at the global level?
• Is there such a thing as sustainable forestry and
  how can we preserve old-growth, virgin forest
  ecosystems?

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Managing Forests

• Up until the 1920s in America, and still today in
  many developing nations, loggers practiced cut
  and run, clear-cutting or selectively logging
  trees from old-growth (never before cut), primary
  (or virgin) forests and then moving on to the
  next.
• No attempt was made to repair hillslopes from the
  physical damage done in logging or to plant
  seedlings, leaving the forest to regenerate
  naturally as best it could.
• Cut forests would undergo the regenerative
  processes known as secondary succession until a
  new climax cover was reached (CRO p65-57).
• This secondary forest would usually be
  inferior, i.e. much less ecologically and
  commercially valuable than the forest it replaced.

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Creating Change

• Depending on climate, geology, topography and
  other biogeophysical factors, natural forests can
  vary from virtually homogeneous stands of the
  same species (e.g. temperate coastal redwoods) to
  highly heterogeneous mixes of many species (e.g.
  tropical rainforests).
• Regardless, natural forests are seldom
  homogeneous with respect to age with a wide
  range of differently aged specimens from the
  senescent (old declining growth rates) to the
  sapling (young accelerating growth).
• When loggers have clear-cut forests, there has
  thus been a lot of wastage (trash trees), and
  where selective cuts have been made, there has
  been lots of collateral damage and unbalanced
  biodiversity reduction.

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Clear Cutting

• Clear cutting has historically been the preferred
  mode of operation of commercial loggers (and is
  used today on even-aged production forests).
• Clear cutting is cheap, quick, simple, frequently
  automated, highly profitable and makes it easier
  to establish monocultural production forests
  afterward.
• In tropical forests, clear-cutting allows for
  subsequent slash-and-burn to open up land for
  farming or grazing.
• Clear cutting has many on-site and off-site
  negative effects accelerated erosion loss of
  stream shade slope surface instability creation
  of even-age, homogeneous stands vulnerable to
  fire, disease, drought temporary (and often
  permanent) elimination of biodiversity and
  visual blight.
• In the tropical context, clear-cut forests will
  take thousands of years to recover, if at all,
  due to the broken nutrient cycle.

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Deforestation clear cutting for agriculture and
logging
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Modern Forest Problems

• Forest problems today can be considered from
  different causal perspectives, for example
• Technical/Economic the industrialization of
  logging (huge multi-nationals) has led to a
  factory approach large-scale, high
  specialization (mono-culture), profit-driven,
  externality-prone, frequently subsidized,
  disconnected markets/sources.
• Supply failure to care for and to actively
  regenerate logged forests has made it difficult
  to meet current and future demands for wood
  products without resorting to logging virgin
  stands.
• Demand failure to reuse or recycle wood
  products (e.g. paper recycling) has maintained
  higher than necessary demands for pulp and lumber
  materials (added to this is the desire for
  low-cost wood and paper which encourages
  externalities and use of old growth see above).
• Cultural the pressing need for building and
  farming land requires the elimination of the
  forest above, and the demand for fuelwood eats
  away at forest margins.

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Regional Differences

• According to WRI (2001) data assessment,
  industrialized nations increased total forest
  area 2.7 from 1980-95 but in the developing
  nations, cover declined by 10.
• In Africa, the main problem has been the need for
  land for subsistence agriculture (although
  firewood is a big issue too) to meet the needs of
  mushrooming rural populations.
• In Latin America, the key factors have been
  clearance for cattle ranching, flooding of land
  for hydropower and the building of cities out
  into forests.
• In Asia, the key factors have been subsistence
  agriculture expansion and industrial logging,
  frequently for export of hardwoods (note Asian
  loggers are increasingly active in Latin America).

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Importance of Deforestation

• Wood products worldwide are valued at 2 of
  global GDP, for some nations providing gt30 of
  foreign income (WRI 2001).
• Plantations only supply some 22 of global lumber
  and fiber production, the rest coming from
  primary and secondary forests.
• Fuelwood supplies 30 of the energy in developing
  countries 2 billion rely on it as their main or
  only source of energy.
• Land use change through deforestation may be
  responsible for some 20 of all carbon additions
  to our atmosphere as well as for a reduction in
  CO2 fixing.
• Where deforestation occurs over a significant
  extent, local climate can be altered because of
  lower water vapor levels, warmer average
  temperatures and lower precipitation levels (as
  much as 30).
• Over the next 20 years, if deforestation rates
  continue, some 4-8 of all forest species will
  become extinct, many before we have even
  discovered them.

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Key changes needed

• The pressure on world forests is clearly related
  to efficiency on the downstream side, both in the
  conversion of logs to forest products and in the
  use of those forest products.
• Mills can use logs more efficiently by producing
  products made out of otherwise wasted materials
  particle board, fiberboard and so forth.
• Consumers can recycle wood (e.g. after
  remodelling existing buildings) and paper fibers.
• Firewood users can adopt more efficient
  fireplaces or stoves that produce more useful
  heat from a given mass of firewood, or switch to
  other types of cookers such as solar ovens.
• If as many trees can be grown each year as cut,
  in theory the forestry industry can have no net
  effect on global warming, even if trees are used
  as biofuel.
• Similarly, sustainable agriculture in the tropics
  would allow food needs to be met continuously
  from existing farmland without exhausting the
  soil and forcing people to cut down more forest
  for the land below (however, only with population
  control and/or imported food will the demand for
  new land disappear).

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Multiple Use Sustained Yield

• Forest management is called silviculture.
• Many countries now have enshrined in laws the
  notion that forests have multiple uses
  watershed protection, recreation and so forth
  and limit what can be done to them to preserve
  some of these other values (e.g. prohibit logging
  within 50 meters of a stream).
• A related concept is the sustained yield
  principle, enshrined in US law in 1960 and based
  on practices of German forest managers.
• In this principle, for a given demand, the total
  acreage of land cut is kept to a minimum by
  planting and rearing as many trees on the land as
  was cut before.
• Thus, after a given rotation period is past, i.e.
  when replanted cuts reach maturity, all future
  demands can be met from already cut land,
  assuming demands do not rise.

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A 45 Year Sustained Yield Rotation
1
21
13
42
26
35
9
30
17
29
8
2
33
44
3
22
38
25
14
23
40
18
39
12
34
4
10
36
5
45
32
43
24
41
20
28
11
27
19
6
37
15
31
7
16
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Forest Management Plans

• To be granted logging permits, land owners or
  concessionaires must now submit forest management
  plans to federal or state forestry officials,
  prepared by certified professional foresters.
• These must contain appropriate environmental
  impact assessments and preventive measures.
• Plans are based on an appropriate silviculture
  system which will vary depending on the type of
  forest, tree species, and so forth.
• Foresters can choose even-age methods or
  uneven-age methods of harvesting.
• Plans contain appropriate steps to prevent and
  deal with disease outbreaks, pests, fire
  management and so forth.

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Fragmentation Impacts

• Fragmentation by roads and other selective
  clearings leads to invasive species proliferation
  due to access improvements and edge effects.
• Results in isolated gene pools and long-term loss
  of genetic biodiversity within species
  populations.
• Ecological conservation involves efforts to
  create uninterrupted, contiguous habitat with a
  buffer zone around it to minimize edge impacts on
  the nucleus often called bioreserves.
• Frequently, buckshot development occurs, leading
  to a mosaic-type land-use pattern which
  drastically eats into habitat and results in
  species elimination.
• One of the consequences of forest fragmentation
  is increased impacts of urban-wildland fires like
  those that just ravaged Southern California.

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Fragmentation Impacts on Habitat
Highly modified outer edge (Edge effects
invasive species, noise, etc.)
Undisturbed nucleus High biodiversity, Large
gene pools
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Reduced Intact Nuclei and Isolated Gene Pools
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