**2. Forest biomass**

seen as one of the greatest environmental problems facing the twenty-first century [1–3]. The impacts resulting from this period of great change begin to take place, are felt and will affect the whole world, every ecosystem, every nation, and every human endeavor [4]. Scientific consensus points to emissions of greenhouse gases, largely from the burning of fossil fuels, as the primary culprit behind this problem [5]. In this regard, one important effort to reduce greenhouse gases in the atmosphere is to immediately replace fossil fuels with renewable

In general, biomass is the total weight or volume of organisms in a given area or volume. Biomass is defined as the total amount of living matter above the surface of a tree and is expressed by tons of dry weight per unit area [6]. For forest, biomass itself is defined as the overall volume of living things of all species at a given time and can be divided into three main groups, viz. trees, shrubs, and other vegetation [7]. Forest biomass is highly relevant to climate change issues. Forest biomass plays an important role in the biogeochemical cycle, especially in the carbon cycle. From the total forest carbon, about 50% is stored in forest vegetation. As a consequence, forest damage, fire, logging or illegal logging, and so on will increase the amount of carbon in the atmosphere. In general, the dynamics of carbon in nature can be explained simply by the carbon cycle. The carbon cycle is a biogeochemical cycle that includes the exchange/transfer of carbon between the biosphere, the pedosphere, the geosphere, the hydrosphere, and the earth's atmosphere. The carbon cycle is actually a complex process and every process interacts with other processes. Plants

store it in plant tissue. Until the time carbon is refluxed into the atmosphere, the carbon will occupy one of a number of carbon pools. All the components of the vegetation of trees, shrubs, lianas, and epiphytes are part of above biomass. Below the soil surface, plant roots are also carbon stores other than the soil itself. For example, in peat soils, the amount of carbon stores may be greater than the carbon deposits on the surface. Carbon is also stored in dead organic materials and biomass-based products such as wood products both when used or already in the landfill. Carbon can be stored in carbon pools for long periods or only briefly. Increasing the amount of carbon stored in this carbon pool represents the amount of carbon absorbed from the atmosphere [8]. The role of forest biomass is greater after having financial value in mechanism of carbon trading. Carbon markets need a unit of trade. For carbon, this is one ton of greenhouse gas emissions expressed as carbon dioxide

through multiplication by the global warming potential of the gas. This is the physics of the gas in the atmosphere that results in energy being absorbed rather than radiated out

That is why there is much research on the measurement of forest biomass from all forest components. In its development, forest biomass measurements include all living biomass aboveand below ground, such as trees, shrubs, palms, saplings, and other undersea plants, creeping plants, lianas, epiphytes, etc., and, in addition, biomass from dead plants such as dead wood and litter. Since carbon in the forest can be traded in the carbon market, an accurate mechanism for measuring forest biomass is required. Therefore, the purpose of this chapter is to inform the importance of measuring forest biomass as it forms the basis for carbon accounting

e). Besides that, each greenhouse gas can be converted to a ton of CO<sup>2</sup>

) through the process of photosynthesis and

e

energy sources.

6 Renewable Resources and Biorefineries

equivalents (tCO<sup>2</sup>

on carbon trading.

to space.

will reduce the carbon in the atmosphere (CO<sup>2</sup>

In general, forest biomass is the mass of the above-ground portion of live trees per unit area. It is a basic forest property linked to the productivity and processes of the forest ecosystem, and is an important indicator of the carbon stock that will help determine the contribution of forests to the global carbon cycle. Methods for estimating forest biomass have been largely undertaken from models or using allometric methods, forest inventory, applications of remote sensing data and geographical information system (GIS). The method has been widely practiced in various pilot areas in almost all countries in the world.

The allometric method for biomass assessment was first discovered by Kittredge [9] in the form of a logarithmic formulation as follows:

$$\mathbf{Y} = \mathbf{a}\mathbf{X}^{\flat} \tag{1}$$

where Y = dependent variable (in this case, biomass content); X = independent variable (in this case, may be the trunk diameter or height of tree, root, wide tree canopy, etc.); and a, b = constants. Allometric method is a method of measuring plant growth expressed in terms of exponential relationships or logarithms between plant organs that occur harmoniously and changes proportionally [10]. The methods used to measure carbon content in forest biomass can be done in three ways as follows:

	- **a.** carbon content of vegetation trees = 0.5 × biomass weight [11]
	- **b.** forest carbon content = 80% × charcoal weight [12]
	- **c.** stem biomass = stem volume × wood density
	- **d.** total above-ground biomass (tree biomass above ground) = biomass stem × BEF (Biomass Expansion Factor).

**4.** The types of allometric equations formulated include allometric equations based on types of forest, types of tree, and the parts of trees. For example: *Swietenia mahogany*, Y = 0.9029 (D<sup>2</sup> .H)0.6840; *Dalbergia latifolia*, Y= 0.7458 (D<sup>2</sup> .H)0.6394; and Tectona grandis, Y= 0.0149 (D<sup>2</sup> .H)1.0835 where Y is the total biomass of trunk, branch, and leaf; D is the diameter at breast height; and H the total height. The total biomass of five combined tree species (*Swietenia mahogany, Dalbergia latifolia, Tectona grandis, Paraserianthes falcataria, and Acacia auriculiformis*) Y = 0.0219(D<sup>2</sup> .H)1.0102 [13]; Y = 0.262 + 1.934 D where Y is the total liana biomass in tropical primary and secondary forests and D is the liana diameter; Y = 2.55 + 0.416 L, where Y is the stem biomass and L is the liana length [14]; for young rain tree or *Albizia saman,* Y = −10,31 0.50 + 1820.89X<sup>1</sup> + 10.89X<sup>2</sup> where X1 = Diameter and X<sup>2</sup> = Height [15]. Besides that, there are also the relationships between above-ground dry plant biomass and stem diameter of liana [16] and bamboo [17–19]. Generally, several generalized allometric equations for tropical forests have been established and also widely used. Unfortunately, application of such generalized equations to individual sites may lead to large errors in biomass estimates especially when the species concerned is poorly represented by the generalized models. In this case, local allometric models are needed to give an accurate estimation [20].

and a digital representation conducive to image processing. This is supported by satellite sensors capable of recording the reflectance spectra of the stands which is a combination of soil reflection spectrum, trees and ground vegetation. Stand reflectance depends on the relative

From Forest Biomass to Carbon Trading http://dx.doi.org/10.5772/intechopen.80395 9

In relation to the search for renewable energy sources for the future, actual forest biomass such as felled and low-value trees can be an alternative in determining renewable energy sources or bioenergy. Thriving markets for these materials will add value to the working forests and provide an important tool for addressing a number of natural conservation goals, including hazardous fuel reduction, degraded forest restoration, habitat management, etc.

Available forest areas are limited by a number of non-market factors, such as environmental regulations, conservation efforts, the value of non-timber forest, and the behavior of landowners. In addition, economic factors will determine where biomass is available and its quantities. National policies of developed countries and global market mechanisms can improve the demand for woody biomass; then, the prices for these materials will tend to increase as well. The given high biomass prices will certainly benefit forest landowners and increase the bottom line for sustainable forest management. In terms of biomass, buyers will increase the cost for existing biomass users. In terms of the pricing process through supply and demand mechanisms in the market, increasing demand will lead energy producers into competition with forest products for timber and residues, or encourage timber harvesting to unsustainable levels. On the other hand, the forest products industry can afford higher prices for wood fibers than most energy producers can meet, due to the high value of wood, pulp/paper, and other wood products relative to energy values. Thus, the availability of biomass at low costs will limit where and to what extent bioenergy is seen as cost-effective. This is especially true as other renewable energy costs (such as wind, geothermal, solar, and water technology) continue to decline.Actually, the economic feasibility of bioenergy will depend on the supply of reliable and affordable raw materials. In this case, bioenergy has more in common with oil, natural gas, or coal than any other form of renewable energy, such as wind, geothermal, and solar. However, unlike fossil fuels, forest biomass is a living resource, subject to biological forces, climates, and natural disasters. Also, unlike fossil fuels, forests are much appreciated, more than just their energy content. People depend on forests for clean water, biodiversity, timber products, recreational opportunities, essential ecosystem services, and for their esthetic and spiritual appeal. The challenge is to build an infrastructure for cost-effective harvesting of reliable biomass supplies without negatively impacting these other values. The following recommendations address the need to develop infrastructure and an atmospheric biomass market that prioritizes conservation goals, ecosystem restoration, and other forest stewardship objectives.

Efforts to address climate change have been made by the international community through greenhouse gas (GHG) emission reduction programs with avoided deforestation and forest degradation through the afforestation/reforestation clean development mechanism (A/R CDM), reducing emission from deforestation and degradation (REDD+), Joint Implementation

amounts of these components within a ground resolution cell.

**3. Handling climate change**

(JI), and voluntary carbon market (VCM) schemes.

In a forest carbon inventory, a calculated carbon pool contains at least four pools of carbon. The pools of carbon are above- and below-ground biomass, dead organic matter, and soil organic carbon.


Remote sensing satellites have been used in many studies on forest biomass successfully. The use of remote sensing is increasingly widespread after supported by the use of spatial analysis in the geographical information system (GIS). That is why the making of forest biomass maps and other thematic maps has been done for many purposes. Remote sensing applications have been able to estimate forest structure and biophysical parameters such as land cover, crown closure, stand height, leaf area index, biomass, volume, etc. The advantages of remote sensing applications include systematic repetition scope with spectral and spatial consistency, the ability to monitor areas of interest over time, suitability for large area coverage, and a digital representation conducive to image processing. This is supported by satellite sensors capable of recording the reflectance spectra of the stands which is a combination of soil reflection spectrum, trees and ground vegetation. Stand reflectance depends on the relative amounts of these components within a ground resolution cell.

In relation to the search for renewable energy sources for the future, actual forest biomass such as felled and low-value trees can be an alternative in determining renewable energy sources or bioenergy. Thriving markets for these materials will add value to the working forests and provide an important tool for addressing a number of natural conservation goals, including hazardous fuel reduction, degraded forest restoration, habitat management, etc.

Available forest areas are limited by a number of non-market factors, such as environmental regulations, conservation efforts, the value of non-timber forest, and the behavior of landowners. In addition, economic factors will determine where biomass is available and its quantities. National policies of developed countries and global market mechanisms can improve the demand for woody biomass; then, the prices for these materials will tend to increase as well. The given high biomass prices will certainly benefit forest landowners and increase the bottom line for sustainable forest management. In terms of biomass, buyers will increase the cost for existing biomass users. In terms of the pricing process through supply and demand mechanisms in the market, increasing demand will lead energy producers into competition with forest products for timber and residues, or encourage timber harvesting to unsustainable levels. On the other hand, the forest products industry can afford higher prices for wood fibers than most energy producers can meet, due to the high value of wood, pulp/paper, and other wood products relative to energy values. Thus, the availability of biomass at low costs will limit where and to what extent bioenergy is seen as cost-effective. This is especially true as other renewable energy costs (such as wind, geothermal, solar, and water technology) continue to decline.Actually, the economic feasibility of bioenergy will depend on the supply of reliable and affordable raw materials. In this case, bioenergy has more in common with oil, natural gas, or coal than any other form of renewable energy, such as wind, geothermal, and solar. However, unlike fossil fuels, forest biomass is a living resource, subject to biological forces, climates, and natural disasters. Also, unlike fossil fuels, forests are much appreciated, more than just their energy content. People depend on forests for clean water, biodiversity, timber products, recreational opportunities, essential ecosystem services, and for their esthetic and spiritual appeal. The challenge is to build an infrastructure for cost-effective harvesting of reliable biomass supplies without negatively impacting these other values. The following recommendations address the need to develop infrastructure and an atmospheric biomass market that prioritizes conservation goals, ecosystem restoration, and other forest stewardship objectives.
