CHAPTER ONE

GENERAL INTRODUCTION

1.1 Introduction

Eucalyptus is a tree which belongs to the family Myrtaceae. It is represented by more than 800 species, and a majority of them are native to Australia (Flores et al., 2016). Species of Eucalyptus are economically important plank production and also being used in the production of essential oils, wood, paper and cellulose (Balbino et al., 2011). Eucalyptus flowers contribute to the production of honey (Birtchnell and Gibson, 2006). Essential oils of Eucalyptus are rich in monoterpenes and are extensively used in pharmaceuticals, perfumes, food flavorants and agrochemicals (Barbosa et al., 2016). Several biological activities, such as acaricidal, antioxidant, antibacterial, insecticidal, fungicide and herbicidal, have been reported for different species of Eucalyptus. These activities are attributed mainly to the chemicals present in the essential oils (Barbosa et al., 2016).

Eucalyptus leaves are rich in essential oil, are used as anti-inflammatory and antibiotic (Farah et al. 2002) In rural area in Africa, it is also used as fuel wood by millions of people and used to drain swamps areas (May and Ash, 1990). This tree is also a durable and attractive material for flooring and timber framing (Hoadley 2000). Despite the apparent benefits and the potential for Eucalyptus to improve rural livelihoods and development initiatives, it is undermined by several scientists and communities.

Wood is a complex biological structure, a composite of many chemistries and cell types acting together to serve the needs of a living plant (Cerutti and Lescuyer, 2011). Attempting to understand wood in the context of wood technology, we have often overlooked the key and basic fact that wood evolved over the course of millions of years to serve three main functions in plants conduction of water from the roots to the leaves, mechanical support of the plant body, and storage of biochemicals. There is no property of wood physical, mechanical, chemical, biological, or technological that is not fundamentally derived from the fact that wood is formed to meet the needs of the living tree. To accomplish any of these functions, wood must have cells that are designed and interconnected in ways sufficient to perform these functions. These three functions (mechanical, chemical, biological ) have influenced the evolution of approximately 20,000 different species of woody plants, each with unique properties, uses, and capabilities, in both plant and human contexts (Louppe and Depommier,  2010). Understanding the basic requirements dictated by these three functions and identifying the structures in wood that perform them allow insight to the realm of wood as an engineering material (Hoadley 2000).

A wide range of engineering properties are used to characterize the performance of wood-based composites. Mechanical properties are typically the most frequently used to evaluate wood-based composites for structural and nonstructural applications. Elastic and strength properties are the primary Criteria to select materials or to establish design or product specifications. Elastic properties include modulus of elasticity (MOE) in bending, tension, and compression. Strength properties usually reported include modulus of rupture (MOR, bending strength), compression strength parallel to surface, tension strength parallel to surface, tension strength Perpendicular to surface (internal bond strength), shear strength, fastener holding capacity, and hardness. Detail studies on laboratory classification of Eucalyptus which is the most used tree type in Bamenda has not been done and so the gap posted by the lack of knowledge in the types available has a great effect on the quality of products produced from this wood type.

Previous studies have reported that m any Eucalyptus species have similar morphologies, making their morphological identifi-cation difficult (Santos et al., 2008; Flores et al., 2016). For instance, E. grandis can be confused with E. dunni, E. deanei Maiden, E. saligna and E. botryoides. In this situation, comparative morpho-anatomical studies, like the present work, can help in the distinction and the identification of the species.  This has pushed the researcher to gain interest by looking for the characteristics that differentiate the different species of Eucalyptus that are being used in Bamenda town.

1.2 Problem Statement

Eucalyptus tree is   an important industrial raw material forest timber product with high level of consumption in the world construction, furniture, ship building, medicine and fuel especially in Cameroon due to its advantages of fast-growing, high-yield, wide-ranging and short-rotation. Bamenda the chief town of North West Regions uses wood for his daily activities with Eucalyptus accounting to over 90% with only few species of other wood types like Iroko, Mahogany, Pine wood available. This study will help us to identify different Eucalyptus wood species in Bamenda. Studying the different types of Eucalyptus wood types found in Bamenda is the first of its kind and will have to provide a baseline study of the wood species in the available in Bamenda. An assessment study on the different Eucalyptus types found in Bamenda will help the wood users to improve the knowledge on quality and purposed of using Eucalyptus in wood works. This explains why the researcher intends to work on Identification of the different types of Eucalyptus found in Bamenda in the North West Region of Cameroon.

1.3 Research Questions

1.3.1 Main Research Question

What are the different Eucalyptus species found in Bamenda?

1.3.2 Research Questions

• What are the different Eucalyptus wood types commonly used in construction and furniture in Bamenda town?
• Which characteristics are used to differentiate between the different types of Eucalyptus used in Bamenda town?
• What is the relationship between quality and maturity level of the different types of Eucalyptus used by wood workers in Bamenda town?

1.4 Objectives

1.4.1 Main Objectives 

To investigate and identify different types of Eucalyptus species that are found in the North West Region, Cameroon.

1.4.2 Specific Objectives

• To evaluate the different Eucalyptus wood types commonly used in construction and furniture in Bamenda town.
• To determine the characteristics that are used to differentiate between the different types of Eucalyptus used in Bamenda town.
• To assess the relationship between quality and maturity level of the different types of Eucalyptus used by wood workers in Bamenda town.