Studies measuring timber is commonly known as the science of measuring forest. Henri S. Groves (1960) in Anonymous (2011) defines the geometry of forests as a science which studies the volume of timber (logs), trees and stands as well as studying the results and growth of the jungle. After World War II evolving application of statistical theory to use a computer, so the geometry timber to follow these developments and the scientists are measuring the wood was followed by learning the basics of mathematics such as calculus, systems analysis, and operations research to support applications in geometry timber.
Geometry of the wood is one of the keys for successful forest management. How can the science of measuring wood plays a role in the success of forest management? Forest management is basically manage the activities of forest land that flora and fauna that is on it, and man who tapped the forest land. In forest management, the important thing to note is the ability to provide solutions to problems that arise during the implementation of forest management, such as:
(1) Is the silvicultural treatments that can generate both regeneration and growth?
(2) Is the species to be planted for reforestation according to the ecology of the forest?
(3) Is the timber products meet the minimum standards of economic if done logging / logging?
(4) Is managed forests have the potential for development of ecotourism?
To answer the above questions forest managers need accurate information so that forest management can provide economic value to all those who were around the forest (not only forest managers but forest communities and governments will also enjoy economies of forest products). Information can be assured of accuracy if in accordance with actual field data. Through the science of measuring timber, in which implement the principles of measuring timber, can be obtained quantitative information on the potential of wood in the forest which can then be useful in decision making managerial level.
Ash’ari et al. (2012) states that the definition of the dimensions are a length with units of a particular size. A space or a particular building has dimensions of length, width and height, so that the measured dimensions can produce the volume or content, which is the result of multiplying the three dimensions of space or owned the building. In line with this definition, then for tree trunks stand has dimensions diameter or circumference and height. As for felling trees or trees after felling has dimensions of diameter or circumference, and length.
These dimensions are then expressed as a tree dimensions measured at the time the measurement is made. Volume stems (usually expressed in m3) is basically the result of multiplying the measured tree dimensions (diameter or circumference and height or length). Thus, the trunk volume is not one dimension of the dimension measured tree trunks although volumes may be measured directly using a measuring instrument Xylometer.
There are two ways to measure the dimensions of trees, both standing trees and fallen trees, which directly and indirectly.
(1) Measurement of direct (direct measurement).
This direct measurement can be made to the diameter or circumference of the trunk, either in a state tree stand or fall. While the height or length can only be performed on fallen trees (logs).
(2) Measurement of indirect (estimate / assessment).
Indirect measurement is usually done by guessing the dimensions measured. How do the dimensions assumed by naked eye or without the aid of any dimension measurement. This method is usually done only for people who are experienced in the field.