**1. Introduction**

The role of forest biomass is now greater due to its ability to cope with global warming. Facts prove that forest cover decreases have caused climate change and various disasters such as flood, landslide, drought, extreme weather, and others. Global climate change is widely

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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 energy sources.

**2. Forest biomass**

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

From Forest Biomass to Carbon Trading http://dx.doi.org/10.5772/intechopen.80395 7

The allometric method for biomass assessment was first discovered by Kittredge [9] in the

Y = aXb (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

**1.** Total harvesting method: This method is commonly done to measure the content of biomass or carbon in vegetation of relatively small size, that is, for the level of shrubs and herbs, for example, the types of agricultural crops as a mixture of agroforestry, such as

**2.** Stratified clip method/allometric method: This method is usually done to measure the content of biomass or carbon in vegetation of relatively large size, such as poles and trees. Implementation of this method in the field is usually done by destruction of sample trees, then separating each section of plant organs that generally include roots, stems, branches, and leaves. Parts of the plant organs are weighed for wet weight (if possible) and sampled for drying (oven) to get biomass value. The biomass content or carbon content of each tree is associated with easily measurable growth variables, such as tree diameter and/or tree height. With the number of samples of varying sizes, the allometric equations can be obtained. **3.** Estimation method: This method is done using commonly used assumptions to estimate the carbon content of forest vegetation. Some commonly used assumptions for estimating

**d.** total above-ground biomass (tree biomass above ground) = biomass stem × BEF (Biomass

peanuts, corn, rice, soybeans, under plants, shrubs, grasses, and others.

**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

practiced in various pilot areas in almost all countries in the world.

form of a logarithmic formulation as follows:

can be done in three ways as follows:

carbon content are as follows:

Expansion Factor).

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 will reduce the carbon in the atmosphere (CO<sup>2</sup> ) through the process of photosynthesis and 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 equivalents (tCO<sup>2</sup> e). Besides that, each greenhouse gas can be converted to a ton of CO<sup>2</sup> e 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 to space.

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 on carbon trading.
