Fact Sheet 4.17. Low-Impact Forest Harvesting
Low-impact harvesting entails harvesting methods that are developed and executed
to provide minimum disturbance to soil, remaining vegetation, and extracted
trees. The practice influences the carbon stock change from trees left in the
forest after harvest, as well as the growth (and corresponding carbon storage)
of new trees and vegetation. It also influences carbon storage in end products
by influencing timber quality and affecting the type of utilization that can
be made of the timber.
Use and Potential
Winjum et al. (1998) estimate regional and global harvest volumes and
corresponding carbon storage and emission changes. Putz and Pinard (1993) and
Pinard and Putz (1996, 1997) demonstrate that reduced-impact logging is an activity
that substantially decreases the emission of carbon in tropical forests because
of reduced damage to soil and remaining trees.
Uncertainties associated with this practice relate to quantification of differences
between carbon stock changes associated with better practices compared to those
normally applied in a country or region. Estimates are needed of damage to soil,
remaining trees, and other vegetation and the consequences of these damages
for carbon stocks. In addition, regarding damage on extracted trees, estimates
of the decay time of end products into which harvested timber is manufactured
are needed. None of these measurements are included in the present IPCC methodology.
Compiling results from several measurements in different forests may make possible
the development of benchmarks for typical high-impact logging in different forest
types and economies.
Monitoring, Verifiability, and Transparency
If the uncertainty factors are adequately met, monitoring and verifying this
practice should be possible. Assumptions and methodologies associated with this
practice are easily explained for replication and assessment of impacts.
In most cases this practice will have positive environmental benefits regarding
biodiversity, recreation, and landscape management; no associated environmental
damage is likely. In addition, this practice is likely to increase the economic
value of remaining trees, as well as logged trees. Boscolo et al. (1997)
estimate the cost efficiency of reduced-impact harvesting in a lowland tropical
rainforest in Malaysia as $5.5 t-1 C. No conflicts are likely. The equity implications
are small. The main barrier that prevents these activities from being implemented
is lack of economic incentives. Without some incentives based on carbon impacts,
costs are likely to remain higher than benefits.
Relationship to IPCC Guidelines
See Fact Sheet 4.12.