Carbon Management

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Lecture 8 Carbon Sequestration in Forestry
1. The importance of global forests
2. The role of forests as carbon sinks and sources
3. Forest carbon conservation, sequestration and
management
4. Global estimates of the carbon sequestration
potential
5. Twelve ways to sequester carbon in forests
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1. The Importance of Global Forests

• 1). Global Forests Area
• The worlds forests cover about 3.4 billion ha
  26 of total land
• 43 of forests are distributed at low latitudes,
  32 at the high
• latitudes, and 25 at mid-latitudes

USA 246 Mha, 32 of the land area Canada 316
Mha, 44 of the land area China 157 Mha, 17 of
the land area Russia 887 Mha, 52 of the land
area
(referenced year 1990)
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2). The Role of Forests
a). Traditional use as sources of food,
shelter, construction materials and fuel
b). Other values (service) such as havens for
human relaxation and recreation, as wildlife
habitats and maintainers of water supplies
c). Additional value their ability to sequester
atmospheric CO2 - carbon sequestration
e.g. at present, mid- and high-latitude forests
sequester over 0.6Pg C /year (USA, Canada, Russia
and China all have large forest carbon sinks)
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2. The role of forests as carbon sinks and sources
a) . The worlds forests (in 1990) contain large
quantities of carbon 1,146 Pg C (Dixon et al.
1994) - 359 in vegetation (62 in the
low-latitude forests) - 787 in soils and
peatlands (54 in high-latitude forests)
b) In 1990, the estimated net carbon flux from
the worlds forests is a sources of 0.90.5 Pg
per year, or about 16 of the amount produced by
the burning fossil fuels and cement manufacture
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At present, mid- and high- latitude forests
sequester over 0.70.2 Pg per year
e.g., USA, Russia and China all have large
forests carbon sinks
Low-latitude forests (in Brazil, Indonesia,
and Zaire) are currently shrinking at a rate of
15 Mha per year, and thereby are a carbon
sources of about 1.6 0.5 per year
Tropical deforestation and land use change are
mainly contributing to this carbon source
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3. Forest Carbon Conservation, Sequestration and
Management

• Forest management practices to conserve and
  sequester C can be grouped into
• four major categories
• Management for C conservation
• Management for C storage
• Management for creating new C sinks
• Management for C substitution

• Management for C Conservation
• Goal mainly to prevent C emissions by
  conserving existing C pools in forest
• vegetation and soil as much as possible

• Management practice
• controlling deforestation

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e.g. The study projects that cumulative
deforestation could be slowed by 138Mha by the
end of 2045 from a base line project of 650 Mha
under future scenario, thus conserving up to 0.5
Pg C per year

• protecting forest in reserves

• changing harvesting regimes

e.g. Peng et al. (2002) suggest that longer
rotations and less intensive harvesting could
increase C sequestration about 36-40 in the
boreal forests in central Canada

• Protecting forest against fire and insect and
  pest outbreaks

e.g. implementation of a fire management system
could increase the near- and long-term C sinks
in Russia by up to 0.1 to 0.6 Pg C per year
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(2) Management for C storage
Goal to expand the storage of C in forest
ecosystems by increasing The area and /or biomass
and soil C density of natural and plantation
forests, and to increase storage in durable wood
products.

• Management practice
• silvicultural treatments as protecting secondary
  forests and other
• degraded forests whose biomass and soil C density
  are less than
• their maximum value and by allowing them to
  sequester C by
• natural or artificial regeneration and enrichment
  of soil C.

- practices to expand or conserve forests also
affect soil C, including a) reduce erosion, b)
improve soil fertility, c) removal of marginal
lands from agricultural production that is
followed by forestation, d) retention of
forest Litter and debris after silvicultural and
logging activities etc
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(3) Management for creating new C sinks
Goal to increase the C sequestration by
expanding tree and forest cover

• Management practice
• establishment of plantations on non-forested
  lands (afforestation)
• increase the tree cover on agricultural or
  pasture lands (agroforestry)

e.g. Nilsson and Schopfhauser (1995) suggested
that the maximum rate of global C sequestration
can be achieved about 1.48 Pg C per year after 60
years since the establishment of the plantation
Fang et al. (2001) indicated that Chinese forest
plantations have sequestered 0.45 Pg C and their
average C density increased from 15.3 to 31.1
Mg/ha since the mid-1970s
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(4) Management for C substitution
Goal to increase the transfer of forest biomass
C into products (e.g. construction materials
and biofuels) rather than using fossil-fuel-based
energy and products, cement-based products and
other building materials.
Management practice
The approach involves expanding the use of
forests for wood products and fuels obtained
either from establishing new forests or
plantations, or increasing the growth of
existing forests through silvicultural treatments.
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4. Global Estimates of the Carbon Sequestration
Potential
Global estimates of the potential amount of C
that could be sequestered and Conserved by forest
management practices between 1995 and 2050.
Latitudinal belt Practice C Sequestered
conserved (Pg) High Forestation 2.4 Mid Fore
station 11.8 Agroforestry 0.7 Low Foresta
tion 16.4 Agroforestry 6.3 Regernaratio
n 11.5-28.7 Slow deforestation 10.8-20.8
Total 60-87
(Ref. Nilsson and Schopfhauser (1995). Climate
Change, 30 267-293)
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5. Twelve Ways to Sequester Carbon in Forests
Carbon sequestration strategies logically focus
both on increasing the storage per hectare and on
increasing the forested area. Binkely et al.
(1997) listed the 12 techniques for sequestering
C in forests
1). Protect against fires
2). Protect against disease and pest insects
3). Salvage dead and dying trees
4). Change rotations
5). Control stand density
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6). Enhance available nutrients
7). Control the water table
8). Select useful species and genotypes
9). Reduce regeneration delays
10). Select an appropriate harvest method
11). Manage logging residues
12). Establish, maintain and manage reserves
Ref. Binkley et al. (1997). Sequestration carbon
in natural forests. Critical Reviews
in Environmental Science and Technology, 27
S23-S45.