Wood biology

Trees are major components of the biosphere and their wood is one of the most important renewable resources. Wood as it exists is the result of an evolutionary process to perfectly meet the three main functions: water transport, mechanical support, and storage of reserve material. Detailed information is provided on the photosynthesis and its basic biochemistry as the process by which trees use light energy to synthesize carbohydrates. Wood formation is presented on the cellular level with the cambium as the responsible tissue. Cell divisions, differentiation steps as well as seasonal rhythms are described. Principles of wood tissue variations as well as heartwood formation are shown. A detailed insight into structure and formation of reaction wood is given and the cellular processes of wound reactions are reflected. Felling, storage, drying, and steaming of wood cause a variety of discolorations, which reduce wood quality. Their underlying physiological processes are explained. Anatomical and also selected chemical characteristics of plantation wood are exemplarily provided for teak, black locust, and Douglas fir. The chapter also comes up with state of the art knowledge on international laws and regulations against trading of illegally logged timber and its products. CITES-protection is another field which requires efficient control mechanisms like wood identification on the basis of anatomical features. Recently, wood identification in pulp, paperwood, and fiberboards received increasing importance. Finally, a brief overview is given on structure and utilization of bamboo, rattan, and three selected palms as monocotyledons which develop wood-like tissue.