Lesson Notes By Weeks and Term v4 - SHS 3

Lesson Video

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Performance objectives

• Define Lesser-Known and Lesser-Used Timber Species (LKS & LUS).
• Classify timber species into LKS and LUS.
• Discuss the uses and benefits of LKS and LUS.
• Identify sources of LKS and LUS in Ghana.

Lesson summary

In Ghana, when we think of wood for building or making furniture, our minds often go straight to popular species like Odum (Iroko), Mahogany, or Sapele. However, our forests are blessed with hundreds of other timber species that are not as famous. This lesson focuses on these "other" trees, which we classify as Lesser-Known Timber Species (LKS) and Lesser-Used Timber Species (LUS). Understanding LKS and LUS is crucial for the future of Ghana's woodwork industry and the health of our forests.

Lesson notes

This section breaks down the core ideas of the lesson. We will start by understanding what makes a timber "well-known" before diving into LKS and LUS. A. Well-Known/Primary Timber Species

These are the "celebrity" trees of the Ghanaian timber industry. They are highly demanded both locally and for export. Characteristics: They have well-established markets, their properties (strength, durability, workability) are widely understood, and there is a consistent supply chain. Examples in Ghana: Odum (Iroko), Mahogany, Sapele, Wawa (for plywood core), Teak (plantation-grown), Ofram. Problem: Over-exploitation of these species has led to scarcity, high costs, and environmental degradation. This is why we must look for alternatives. B. Lesser-Known Timber Species (LKS)

As the name suggests, these are timber species that the general public, and even many woodworkers, do not know much about. They are often abundant in the forest but are not commercially harvested or sold on a large scale. Definition: Lesser-Known Timber Species (LKS) are tree species that are biologically abundant in the forest but are not well-known in the timber market. Their properties, potential uses, and processing requirements are not widely documented or understood. Reasons for being "Lesser-Known": Lack of Information: Limited research on their strength, durability, and how to season (dry) them properly. Processing Difficulties: Some may have high silica content that dulls tools quickly, or they may be prone to warping and cracking during drying. Poor Natural Durability: They may not be resistant to insect or fungal attack without treatment. Market Resistance: Carpenters and customers are often hesitant to try something new, preferring the familiar "tried and tested" woods. Ghanaian Examples of LKS: Denya (*Cylicodiscus gabunensis*): Very heavy, strong, and durable. Difficult to work with but excellent for heavy-duty applications like railway sleepers and bridges. Dahoma (*Piptadeniastrum africanum*): A large, common tree. Wood is durable and suitable for general construction, flooring, and heavy carpentry. Kusia (*Nauclea diderrichii*): A yellowish-brown wood that is very durable and resistant to termites. Good for construction, marine work, and furniture. Esa (*Celtis mildbraedii*): A whitish or pale-yellow wood. Not very durable, but if treated, it can be used for interior joinery, furniture frames, and plywood. C. Lesser-Used Timber Species (LUS)

This category is slightly different. These species are generally *known* to exist and have some documented properties, but their full potential is not being realised. They are underutilised. Definition: Lesser-Used Timber Species (LUS) are tree species that are known to the timber industry and have some established uses, but are not exploited to their full potential. They are often harvested but only used for a narrow range of products, or their availability in the market is inconsistent. Reasons for being "Lesser-Used": Niche Properties: They may have specific characteristics that limit their use to specialised applications. Inconsistent Supply: They might not be harvested as frequently as primary species. Aesthetic Preferences: The colour or grain pattern might not be as fashionable as Mahogany or Odum. Overshadowed by Primary Species: In the past, with plenty of primary species available, there was no incentive to explore the full potential of these secondary species. Ghanaian Examples of LUS: Ofram (*Terminalia superba*): While sometimes considered a primary species, its use is often limited to specific applications like furniture frames and light construction. It has greater potential. Emire (*Terminalia ivorensis*): A light, easy-to-work wood. Often used for furniture, but its potential for high-end joinery and decorative veneers is under-explored. Celtis (*Celtis zenkeri*): Similar to Esa. It is known but often overlooked for furniture in favour of other woods. Good for bentwood work. Afina (*Strombosia glaucescens*): A hard, heavy wood suitable for flooring and construction, but not commonly seen in the mainstream market. D. Summary Table: Differentiating LKS and LUS

Evaluation guide

• Classify Lesser -Known Timber Species (LKS), Lesser -Used Timber Species
• (LUS)
• Critical Thinking and Talk for Learning Approaches: Guide learners through
• whole class session to brainstorm the meaning of the following with open -mindedness: