Land Use, Land-Use Change and Forestry

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4.4.4.4. Overall Contribution

The potential contributions of agroforestry systems to carbon sequestration are summarized in Table 4-1 under the headings of improved management within a land use and land-use change. The latter is an order of magnitude higher than the former, given the lower initial levels of carbon stocks. Overall, agroforestry can sequester carbon at time-averaged rates of 0.2-3.1 t C ha-1. In temperate areas, the potential carbon storage with agroforestry ranges from 15 to 198 t C ha-1 (Dixon et al., 1994), with a modal value of 34 t C ha-1 (Dixon et al., 1993). The associated impacts of agroforestry include helping to attain food security and secure land tenure in developing countries, increasing farm income, restoring and maintaining aboveground and below-ground biodiversity (including corridors between protected forests), serving as CH4 sinks, maintaining watershed hydrology, and decreasing soil erosion.

4.4.5. Forest Management

Forest management is the application of biological, physical, quantitative, managerial, social, and policy principles to the regeneration, tending, utilization, and conservation of forests to meet specified goals and objectives while maintaining forest productivity. Management intensity spans the range from wilderness set-asides to short-rotation woody cropping systems. Forest management encompasses the full cycle of regeneration, tending, protection, harvest, utilization, and access.

A vast number and variety of activities exist and are being developed by researchers to manage forests. The actual outcome of forest management (e.g., whether it sequesters carbon, produces industrial wood or wood fuel, or protects biodiversity) usually can be measured only as the integrated outcome of the suite of practices used, not as the outcome of individual practices evaluated alone. The positive impact of any practice may be realized only if applied in concert with one or more other practices-each of which may have a minimal, or even negative, impact. Thus, for forest management, measuring carbon stocks with a broad definition of the activity (Section 4.3.2) and land-based accounting methods (Section 4.3.3) may lead toward full accounting, particularly if wood products are included in the accounting (Section 2.4.2.2).

The end use of wood products is important for two reasons. First, wood products provide a stored carbon stock that depends on the life span of the product. Wood-in-use stocks are growing larger in many countries, and management choices (efforts to extend useful life, recycling, etc.) can contribute to further growth in these stocks. Second, greater utilization of wood allows reduced use of fossil fuel-by utilizing the wood either directly for energy production or to replace energy-intensive products such as steel, aluminum, plaster board, and bricks.

Forest management in this chapter refers to forestry activities that are not ARD activities as defined in Article 3.3 of the Kyoto Protocol. Although there are many possible forest management activities, the following are examples that are likely to alter carbon stocks:

Brief descriptions of these activities follow (the Fact Sheets provide more detail). The carbon sequestration potential of forestry activities varies considerably between ecosystems, countries, and regions, and few empirical studies exist. Table 4-9 lists some examples of existing studies to illustrate the potential. Finally, it is assumed that forest management practices that are implemented for carbon sequestration purposes will comply with existing multilateral agreements (e.g., the United Nations Convention on Biological Diversity and Ramsar Convention of Wetlands) and the results of the ongoing United Nations Intergovernmental Forum on Forests regarding sustainable forest management.

Table 4-9: Rates of potential carbon gain under selected practices for forestland in various regions of the world.

Practice
Country/Region
Rate of Carbon Gain
(t C ha-1 yr-1)
Time1
(yr)
Other GHGs and Impacts
Notes2

Improved Natural Regeneration
India
0.55
30
 
a

Increased Rotation Length
Canada
0.022
80
Leakage (increased harvest elsewhere)
b
USA
0.036
80
b
The Netherlands
0.035
80
b

Forest Fertilization
Canada
0.03-0.19
20
+N2O, +NOX Ecological changes
b
USA
0.08-0.48
20
b
The Netherlands
0.1-0.6
20
b
Norway
0.44
20
c

Forest Conservation
India
0.48
30
Environmental improvements
a

Reduced Forest Degradation
Tropical/Global
1.7-4.6
40
Environmental improvements
h

Several Practices Combined
USA
3.1
50
Ecological changes
d
Norway
0.12-0.20
20
e

Several Practices Combined, Lobloly Pine
USA
1.2
40
Ecological changes
f
USA
3.5
25
g

Species Change (Aspen to Red Pine)
USA
0.88
80
Ecological changes
f

1 Time interval to which estimated rate applies. This interval may or may not be time required for ecosystem to reach new equilibrium.
2  a. Ravindranath et al. (1999).
   b. Nabuurs et al. (1999).
   c. Lunnan et al. (1991).
   d. Birdsey et al. (2000).
   e. Hoen and Solberg (1994); assuming harvest volume is kept constant.
   f. Row (1996).
   g. Albaugh et al. (1998); refers to intensive fertilization and irrigation on an infertile drained sandy soil in North Carolina. Rate is an average estimate of 3 years of measurements starting in 8-year-old stands.
   h. Based on mean biomass stock differences between non-degraded and degraded tropical forests as reported in FAO (1996). Stock differences are 182, 126, and 70 tons dry matter per hectare for tropical wet, moist, and dry zones, respectively, with carbon content as 50% of dry matter.



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