transpiration. The water absorbed through roots is pushed into the air via very
small pores in leaves called stomata. Moreover, transpiration from the leaf surface
partially absorbs heat from the air passing over and under leaf surfaces. This leads
to a rise in the humidity of the atmosphere and a reduction in the temperature of
the leaf.
Carbon sequestration: The release of CO 2 from human activities is said to be closely
related to climate change. Under such circumstances, trees and forests are capable
of absorbing these CO 2 emissions. Namely, trees capture carbon dioxide from the
atmosphere and transform it into biomass through photosynthesis. The sequestered carbon is then accumulated in the form of biomass, litter, soil organic
matter, and deadwood. Therefore, afforestation is one of the viable options for
C sequestration in terrestrial ecosystems (IPCC 1999; Fang et al. 2001; Lamb
et al. 2005).
Fertilizer production: Soil fertility is one of the significant constraints on tree
growth, and nitrogen is one of the most limiting elements. In general, peat soils
are known to be extremely nutrient poor. As a result, conventional agriculture and
forestry provide nitrogen through chemical fertilizers derived from petroleum, but
such products can cause peat degradation and accelerate peat decomposition.
Moreover, some tree species, such as legumes, are known to symbiotically
associate with nitrogen-fixing organisms and make the soil more fertile. Acacia
species, which are planted in commercial plantations, are one of these legumes.
Symbiotic bacteria live in the root nodules of nitrogen-fixing trees, and these root
nodules are the most important feature of the tree. These symbiotic bacteria fix
nitrogen through the production of ammonia, i.e. they act as a fertilizer factory,
which may improve yield and reduce the use of artificial fertilizer in fields.
Water dam/water cycle: Forests have the function of storing water resources,
mitigating floods and improving water quality, and moderating the amount of
rainwater runoff to rivers. On the other hand, through evapotranspiration, trees
and forests circulate water supplied by rainfall back into the atmosphere. Conversely, without forests, the water cycle (i.e., precipitation and evapotranspiration) would cease to function, which could lead to changes in rainfall patterns in
an area. It has been said that a large part of the world’s food production capacity is
closely linked to global rainfall patterns, in which forests play an important role.
Renewable energy: Biomass power is carbon-neutral electricity generated from
renewable organic material. Tree limbs, tree branches, small trees, and wood
waste are used in biomass power generation to create renewable electricity. The
use of tree biomass as a substitute for fossil fuels can be a longer-term approach,
because harvesting and replanting trees, especially on degraded land, can be
carried out repeatedly if appropriately managed. Additionally, the use of biomass
for energy production helps rural economies grow and enhance energy security
(Baral and Guha 2004).
Soil conservation: Trees can contribute directly by enhancing soil cover, providing
live or dead barriers, and enhancing soil resilience to erosion through the maintenance or build-up of organic matter and desirable physical properties. Moreover, forests develop deep roots to cope with droughts, in contrast to shorter
6 Natural Capital-Based Societies in the Tropics
215
small pores in leaves called stomata. Moreover, transpiration from the leaf surface
partially absorbs heat from the air passing over and under leaf surfaces. This leads
to a rise in the humidity of the atmosphere and a reduction in the temperature of
the leaf.
Carbon sequestration: The release of CO 2 from human activities is said to be closely
related to climate change. Under such circumstances, trees and forests are capable
of absorbing these CO 2 emissions. Namely, trees capture carbon dioxide from the
atmosphere and transform it into biomass through photosynthesis. The sequestered carbon is then accumulated in the form of biomass, litter, soil organic
matter, and deadwood. Therefore, afforestation is one of the viable options for
C sequestration in terrestrial ecosystems (IPCC 1999; Fang et al. 2001; Lamb
et al. 2005).
Fertilizer production: Soil fertility is one of the significant constraints on tree
growth, and nitrogen is one of the most limiting elements. In general, peat soils
are known to be extremely nutrient poor. As a result, conventional agriculture and
forestry provide nitrogen through chemical fertilizers derived from petroleum, but
such products can cause peat degradation and accelerate peat decomposition.
Moreover, some tree species, such as legumes, are known to symbiotically
associate with nitrogen-fixing organisms and make the soil more fertile. Acacia
species, which are planted in commercial plantations, are one of these legumes.
Symbiotic bacteria live in the root nodules of nitrogen-fixing trees, and these root
nodules are the most important feature of the tree. These symbiotic bacteria fix
nitrogen through the production of ammonia, i.e. they act as a fertilizer factory,
which may improve yield and reduce the use of artificial fertilizer in fields.
Water dam/water cycle: Forests have the function of storing water resources,
mitigating floods and improving water quality, and moderating the amount of
rainwater runoff to rivers. On the other hand, through evapotranspiration, trees
and forests circulate water supplied by rainfall back into the atmosphere. Conversely, without forests, the water cycle (i.e., precipitation and evapotranspiration) would cease to function, which could lead to changes in rainfall patterns in
an area. It has been said that a large part of the world’s food production capacity is
closely linked to global rainfall patterns, in which forests play an important role.
Renewable energy: Biomass power is carbon-neutral electricity generated from
renewable organic material. Tree limbs, tree branches, small trees, and wood
waste are used in biomass power generation to create renewable electricity. The
use of tree biomass as a substitute for fossil fuels can be a longer-term approach,
because harvesting and replanting trees, especially on degraded land, can be
carried out repeatedly if appropriately managed. Additionally, the use of biomass
for energy production helps rural economies grow and enhance energy security
(Baral and Guha 2004).
Soil conservation: Trees can contribute directly by enhancing soil cover, providing
live or dead barriers, and enhancing soil resilience to erosion through the maintenance or build-up of organic matter and desirable physical properties. Moreover, forests develop deep roots to cope with droughts, in contrast to shorter
6 Natural Capital-Based Societies in the Tropics
215