Wood and Fiber Anatomy PDF

FPPS 111 WOOD AND FIBER ANATOMY INTRODUCTION Wood anatomy is the science of separating the different parts of wood to analyze their situation, structure and function within the material. Emphasis is given on features that could assist in the identification of an unknown samp...

FPPS 111 WOOD AND FIBER ANATOMY INTRODUCTION Wood anatomy is the science of separating the different parts of wood to analyze their situation, structure and function within the material. Emphasis is given on features that could assist in the identification of an unknown samples as well as on the different characteristics that could influence the proper utilization of the material. Wood is the hard, fibrous tissue that comprises the major part of stems, branches and roots of trees. It is essentially the cell wall material of cells produced during cell division. Once the cell dies, it will leave behind its cell wall which could be utilized as lumber, plywood, etc. There are three types of cells present in plants; 1. Conducting cells- elongated, axial cell which serves as water and food material conduits of plants. 2. Support cells – elongated axial cells that provide mechanical support to the plant. 3. Storage cells – short, thin-walled cells with living protoplasm. They are concerned with food storage and distribution. The proportion of these individual cell types vary within the plant depending on the species, position within the stem. This provides complexity in wood properties as well as dictates the proper utilization of the material. IMPORTANCE OF THE COURSE TO: 1. Forestry - assist foresters in the proper collection of forest revenues. 2. Taxonomy – useful in the identification of unknown samples for proper documentation. 3. Phylogenetic studies – helpful in determining the origin of a particular sample. 4. End – use determination – efficient and maximized material conversion. DISTINGUISHING WOODY FROM NON-WOODY PLANTS  1. Must be vascular plants. Possess specialized conducting tissues namely the xylem and the phloem. 2. Must be perennial plants. 3. Must possess a stem that persists from year to year. 4. Exhibit secondary thickening or growth in diameter. TYPES OF WOODY PLANTS 1. Tree - woody plant that attains a height of at least 20 feet. Usually has a single self-supporting stem or trunk. 2. Shrub – woody plant that seldom exceeds 20 feet in height and usually has a number of stems. 3. Woody Lianas – climbing wood vines. Able to climb upward in seek of sunlight by twinning, clambering to other trees. Sometimes produce aerial roots or tendrils. SOFTWOODS AND HARDWOODS Based on botanical origin woody plants are further classified into softwoods and hardwood, both of which belong to the division spermatophyte. 1. Softwoods – belongs to the gymnospermae subdivision characterized by plants having needle like leaves, seeds borne naked. Commonly known as evergreens since most remain green all year round. 2. Hardwoods – belongs to the angiospermae subdivision characterized by plants having broad leaves with seed enclosed in ovaries e.g., fruits. Commonly known as deciduous plants Besides the more obvious differences in external appearance, these two also differ in structural make-up. Cell types, their relative number and their arrangement within the structure differ from one another resulting to their variation in properties. WOOD MONOCOTS One conspicuous feature of many tropical floras is the presence of tree-like monocotyledonous plant with large and long-lived trunks e.g., Palms, rattan, bamboos etc. OTHER PLANT FIBER SOURCES 1. Straw – use for course corrugated boards, solid fiber board and low quality wrapping papers, Ex. Rice straw, wheat etc. 2. Esparto – grass occurring in Spain and Northern Africa. 3. Sugarcane Bagasse 4. Bamboo 5. Manila rope – used in making flour, cement bags and other bags. 6. Cotton stalks 7. Leaf fibers – abaca, pineapple etc.